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  • jQuery code not working in Google Chrome...

    - by Jonathan
    Hi, I have writen a simple jQuery code to control ajax tabs navigation.. Its working in good on FireFox but in Chrome it working in one page but not in the home page I don't know why... Its really simple code just a lot of animations and callbacks and stuff like that.. here's the code: jQuery.fn.tabs = function({movieID, movieTitle}) { var tabsWrap = '#movie_details_wrap'; var tabsContent = '#tab_content'; var firstTab = '#tab_detalles'; var postPHP = 'index.php?controlador=pelicula'; //When page loads... first tab actions $('ul.tabs_nav a:first').addClass('active'); //Activate first tab nav $.get(postPHP, {"activeTab": firstTab, "movieID": movieID}, function(response){ $(tabsContent).html(response); // insert response into the faded out div $(tabsWrap).animate({ // animate the wrap div using the new container div height height: $(tabsContent).height() + "px" }, function() { $(tabsContent).fadeIn(); // fade in the div with all the info }); }); //On Click Event $('ul.tabs_nav li').click(function() { $('ul.tabs_nav a').removeClass('active'); //Remove any 'active' class $(this).find('a').addClass('active'); //Add 'active' class to selected tab var activeTab = $(this).find('a').attr('href'); //Find the href attribute value to identify the active tab + content var orgHeight = $(tabsContent).height() + 'px'; // get original height $(tabsWrap).css('height', orgHeight); // set height with css to freeze the wrap div when we hide the inner div $(tabsContent).fadeOut(200, function() { // fade out the inner div // send data by ajax (post) $.get(postPHP, {"activeTab": activeTab, "movieID": movieID , "movieTitle": movieTitle}, function(response){ $(tabsContent).html(response); // insert response into the faded out div $(tabsWrap).animate({ // animate the wrap div using the new container div height height: $(tabsContent).height() + "px" }, function() { $(tabsContent).fadeIn(); // fade in the div with all the info }); }); }); return false; }); }; Here's the HTML: <script type="text/javascript"> $(document).ready(function(){ $('.tabs_nav').tabs({movieID:'135353', movieTitle: 'Some Title'}); }); </script> <!--Navigation--> <ul id="details_nav" class="tabs_nav"> <li><a href="#tab_detalles">Detalles</a></li> <li><a href="#tab_criticas">Criticas</a></li> <li><a href="#tab_posters">Posters</a></li> <li><a href="#tab_trailers">Trailers</a></li> </ul> <div class="border_wrap"> <div id="movie_details_wrap"> <div id="tab_content"> <!--Tabs content here--> </div> </div> </div>

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  • HTML 5 <video> tag vs Flash video. What are the pros and cons?

    - by Vilx-
    Seems like the new <video> tag is all the hype these days, especially since Firefox now supports it. News of this are popping up in blogs all over the place, and everyone seems to be excited. But what about? As much as I searched I could not find anything that would make it better than the good old Flash video. In fact, I see only problems with it: It will still be some time before all the browsers start supporting it, and much more time before most people upgrade; Flash is available already and everyone has it; You can couple Flash with whatever fancy UI you want for controlling the playback. I gather that the tag will be controllable as well (via JavaScript probably), but will it be able to go fullscreen? The only two pros for a <video> tag that I can see are: It is more "semantic" - which probably holds no importance to a whole lot of people, including me; It is not dependent on a single commercial 3rd party entity (Adobe) - which I also don't see as a compelling reason to switch, because free players and video converters are already available, and Adobe is not hindering the whole process in any way (it's not in their interests even). So... what's the big deal? Added: OK, so there is one more Pro... maybe. Support for mobile devices. Hard to say though. A number of thoughts race through my head about the subject: How many mobile devices are actually able to decode video at a decent speed anyway, Flash or otherwise? How long until mainstream mobile devices get the <video> support? Even if it is available through updates, how many people actually do that? How many people watch videos on web pages on their mobile phones at all? As for the semantics part - I understand that search engines might be able to detect videos better now, but... what will they do with them anyway? OK, so they know that there is a video in the page. And? They can't index a video! I'd like some more arguments here. Added: Just thought of another Cons. This opens up a whole new area of cross-browser incompatibility. HTML and CSS is quite messy already in this aspect. Flash at least is the same everywhere. But it's enough for at least one major browser vendor to decide against the <video> tag (can anyone say "Internet Explorer"?) and we have a nice new area of hell to explore. Added: A Pro just came in. More competition = more innovation. That's true. Giving Adobe more competition will probably force them to improve Flash in areas it has been lacking so far. Linux seems to be a weak spot for it, cited by many.

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  • center menu within the 960 grid

    - by Kyle Monti
    I have been working on 960 grid,(http://960.gs/) and I used an old style menu i've used in the past from a few years ago and for some reason with the 960 grid, the menu is floating left and I want it centered. ul#menu { width:940px; height:61px; background: url(../images/menu_bg.png) no-repeat; list-style:none; padding-top:0; padding-left:0; margin: 0; } ul#menu li { float:left; } ul#menu li a { background: url(../images/menu_splice_color.png) no-repeat scroll top left; display:block; height:61px; position:relative; } ul#menu li a.shel { width:135px; } ul#menu li a.golf { width:84px; background-position:-135px 0px; } ul#menu li a.pro { width:119px; background-position:-219px 0px; } ul#menu li a.event { width:94px; background-position:-338px 0px; } ul#menu li a.member { width:148px; background-position:-432px 0px; } ul#menu li a.bistro { width:91px; background-position:-580px 0px; } ul#menu li a.contact { width:115px; background-position:-671px 0px; } ul#menu li a span { background: url(../images/menu_splice_color.png) no-repeat scroll bottom left; display:block; position:absolute; top:0; left:0px; height:100%; width:100%; z-index:100; } ul#menu li a.shel span { background-position:0px -61px; } ul#menu li a.golf span { background-position:-135px -61px; } ul#menu li a.pro span { background-position:-219px -61px; } ul#menu li a.events span { background-position:-338px -61px; } ul#menu li a.member span { background-position:-432px -61px; } ul#menu li a.bistro span { background-position:-580px -61px; } ul#menu li a.contact span { background-position:-672px -61px; } and my generic html markup is <div class="container_16"> <!-- Navigation Start --> <div class="grid_16"> <ul id="menu"> <li><a href="#" class="shel"><span></span></a></li> <li><a href="#" class="golf"><span></span></a></li> <li><a href="#" class="pro"><span></span></a></li> <li><a href="#" class="events"><span></span></a></li> <li><a href="#" class="member"><span></span></a></li> <li><a href="#" class="bistro"><span></span></a></li> <li><a href="#" class="contact"><span></span></a></li> </ul> </div> <div class="clear"></div> </div> And I use jquery animations to roll over the images. $(function() { $("ul#menu span").css("opacity","0"); $("ul#menu span").hover(function () { $(this).stop().animate({ opacity: 1 }, "slow"); }, function () { $(this).stop().animate({ opacity: 0 }, "slow"); }); });

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  • Image change on mouseover with jQuery..

    - by playahabana
    Hi, I am a comlete beginner to pretty much all things web design and am trying to construct my first website. I am attempting to hand code it without the ue of a CMS in order to learn as much as possible as quickly as possible. I am trying to make an imge change on mouseover for my top nav menu, and have the following jQuery functions: $(document).ready(function(){ $(".navlist img").each(function) { rollsrc = $(this).attr("src"); rollON = rollsrc.replace(/.jpg$/ig,"_link.png"); $("<img>").attr("src",rollON); $(".navlist a").mouseover(function(){ }); imgsrc= $(this).children("img").attr("src"); matches = imgsrc.match(/_link.png); if (!matches) { imgsrcON = imgsrc.replace(/.jpg$/ig,"_link.png"); $(this).children("img").attr("src", imagesrcON); } $(".navlist a").mouseout(function(){ $(this).children("img").attr("src", imgsrc); }); }); my html is as follows: <div id="nav"> <ul class="navmenu"> <li><a href="index.html"><img class="swap" src="images/links/home.jpg" alt="Home" border="none"></a></li> <li><a href="#"><img class="swap" src="images/links/ourbar.jpg" alt="Our Bar" border="none"></a> <ul class="navdrop"> <li ><a href="#"><img class="swap" src="images/links/cockteles.jpg" alt="Our Cocktails" border="none"></a></li> <li ><a href="#"><img class="swap" src="images/links/celebrate.jpg" alt="Celebrate in Style" border="none"></a></li> </ul> </li> <li><a href="#"><img class="swap" src="images/links/ourcigars.jpg" alt="Our Cigars" border="none"></a> <ul class="navdrop"> <li><a href="#"><img class="swap" src="images/links/edicionlimitadas.jpg" alt="Edition Limitadas" border="none"></a></li> <li><a href="our_cigars.html"><img class="swap" src="images/links/cigartasting.jpg" alt="Cigar Tastings" border="none"></a></li> </ul> </li> <li><a href="#"><img class="swap" src="images/links/personalcigar.jpg" alt="Personal Cigar Roller" border="none"></a></li> <li><a href="our_cigars.html"><img class="swap" src="images/links/photogallery.jpg" alt="Photo Gallery" border="none"></a></li> <li><a href="#"><img class="swap" src="images/links/contactus.jpg" alt="Contact Us" border="none"></a></li> </ul></div></div><!--end banner--> the image src for the alt image is in the form eg."images/links/home_link.png" and is the same for every image. I have checked this and checked this, could some body please give me a pointer as to where I am going wrong? Or a pointer to a tutorial for this effect? I have looked at a few and this seems to be the best for what I am attempting, but as I said I don't really know what I'm doing so any advice gratefully received.....

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  • upload file on database through php code

    - by ruhit
    hi all I have made an application to upload files and its workingout well.now I want to upload my files on database and I also want to display the uploaded files names on my listby accessing the database....so kindly help me. my codes are given below- function uploadFile() { global $template; //$this->UM_index = $this->session->getUserId(); switch($_REQUEST['cmd']){ case 'upload': $filename = array(); //set upload directory //$target_path = "F:" . '/uploaded/'; for($i=0;$i<count($_FILES['ad']['name']);$i++){ if($_FILES["ad"]["name"]) { $filename = $_FILES["ad"]["name"][$i]; $source = $_FILES["ad"]["tmp_name"][$i]; $type = $_FILES["ad"]["type"]; $name = explode(".", $filename); $accepted_types = array('text/html','application/zip', 'application/x-zip-compressed', 'multipart/x-zip', 'application/x-compressed'); foreach($accepted_types as $mime_type) { if($mime_type == $type) { $okay = true; break; } } $continue = strtolower($name[1]) == 'zip' ? true : false; if(!$continue) { $message = "The file you are trying to upload is not a .zip file. Please try again."; } $target_path = "F:" . '/uploaded/'.$filename; // change this to the correct site path if(move_uploaded_file($source, $target_path )) { $zip = new ZipArchive(); $x = $zip->open($target_path); if ($x === true) { $zip->extractTo("F:" . '/uploaded/'); // change this to the correct site path $zip->close(); unlink($target_path); } $message = "Your .zip file was uploaded and unpacked."; } else { $message = "There was a problem with the upload. Please try again."; } } } echo "Your .zip file was uploaded and unpacked."; $template->main_content = $template->fetch(TEMPLATE_DIR . 'donna1.html'); break; default: $template->main_content = $template->fetch(TEMPLATE_DIR . 'donna1.html'); //$this->assign_values('cmd','uploads'); $this->assign_values('cmd','upload'); } } my html page is <html> <link href="css/style.css" rel="stylesheet" type="text/css"> <!--<form action="{$path_site}{$index_file}" method="post" enctype="multipart/form-data">--> <form action="index.php?menu=upload_file&cmd=upload" method="post" enctype="multipart/form-data"> <div id="main"> <div id="login"> <br /> <br /> Ad No 1: <input type="file" name="ad[]" id="ad1" size="10" />&nbsp;&nbsp;Image(.zip)<input type="file" name="ad[]" id="ad1" size="10" /> Sponsor By : <input type="text" name="ad3" id="ad1" size="25" /> <br /> <br /> </div> </div> </form> </html>

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  • How do I delete files in a class?

    - by user3682906
    I want to have a CRUD management on my gallery but I have no idea how. I have searched the internet but I did not find what I was looking for. This is my class: class Gallery { public function renderImages($map) { $images = ""; foreach (glob($map ."*.{jpeg,jpg,png,gif}", GLOB_BRACE) as $image){ $images .= "<a href='".$image."' data-lightbox='afbeelding'><img src='".$image."' class='thumbnail'></img></a>"; } return $images; } } and this is my gallery: <div class="gallery"> <center> <a href="index.php">Back:</a> <style> body { margin:0; padding:0; background:#efefef; font-family: "Helvetica Neue", helvetica, arial, sans-serif; color: black; text-align:center; /* used to center div in IE */ } </style> <?php $gallery = new Gallery(); echo $gallery -> renderImages("../images/"); $connection = new DatabaseConnection(); $render = new RenderData(); $page = 1; if(isset($_GET['page'])) { $check = new CheckData(); if($check->PageCheck($_GET['page'])) { $page = $_GET['page']; } } ?> <table> <div id="Intro"> <tr> <td>Hieronder kan je uploaden.</td> </tr> </div> <tr> <td>Max. 500000000Bytes</td> </tr> <tr> <form action="pages/upload_file.php" method="post" enctype="multipart/form-data"> <td><label for="file">Filename:</label></td> </tr> <tr> <td><input type="file" name="file" id="file"></td> </tr> <tr> <td><input type="submit" name="submit" value="Submit"></td> </tr> <tr> <td><input type="submit" name="delete" value="Delete"></td> </tr> </form> </table> How do I make a CRUD management on this? I want to select the photo and then delete it from my computer. I hope you guys can help me out...

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  • CakePHP access indirectly related model - beginner's question

    - by user325077
    Hi everyone, I am writing a CakePHP application to log the work I do for various clients, but after trying for days I seem unable to get it to do what I want. I have read most of the book CakePHP's website. and googled for all I'm worth, so I presume I am missing something obvious! Every 'log item' belongs to a 'sub-project, which in turn belongs to a 'project', which in turn belongs to a 'sub-client' which finally belongs to a client. These are the 5 MySQL tables I am using: mysql> DESCRIBE log_items; +-----------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | date | date | NO | | NULL | | | time | time | NO | | NULL | | | time_spent | int(11) | NO | | NULL | | | sub_projects_id | int(11) | NO | MUL | NULL | | | title | varchar(100) | NO | | NULL | | | description | text | YES | | NULL | | | created | datetime | YES | | NULL | | | modified | datetime | YES | | NULL | | +-----------------+--------------+------+-----+---------+----------------+ mysql> DESCRIBE sub_projects; +-------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | varchar(100) | NO | | NULL | | | projects_id | int(11) | NO | MUL | NULL | | | created | datetime | YES | | NULL | | | modified | datetime | YES | | NULL | | +-------------+--------------+------+-----+---------+----------------+ mysql> DESCRIBE projects; +----------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | varchar(100) | NO | | NULL | | | sub_clients_id | int(11) | NO | MUL | NULL | | | created | datetime | YES | | NULL | | | modified | datetime | YES | | NULL | | +----------------+--------------+------+-----+---------+----------------+ mysql> DESCRIBE sub_clients; +------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | varchar(100) | NO | | NULL | | | clients_id | int(11) | NO | MUL | NULL | | | created | datetime | YES | | NULL | | | modified | datetime | YES | | NULL | | +------------+--------------+------+-----+---------+----------------+ mysql> DESCRIBE clients; +----------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | varchar(100) | NO | | NULL | | | created | datetime | YES | | NULL | | | modified | datetime | YES | | NULL | | +----------+--------------+------+-----+---------+----------------+ I have set up the following associations in CakePHP: LogItem belongsTo SubProjects SubProject belongsTo Projects Project belongsTo SubClients SubClient belongsTo Clients Client hasMany SubClients SubClient hasMany Projects Project hasMany SubProjects SubProject hasMany LogItems Using 'cake bake' I have created the models, controllers (index, view add, edit and delete) and views, and things seem to function - as in I am able to perform simple CRUD operations successfully. The Question When editing a 'log item' at www.mydomain/log_items/edit I am presented with the view you would all suspect; namely the columns of the log_items table with the appropriate textfields/select boxes etc. I would also like to incorporate select boxes to choose the client, sub-client, project and sub-project in the 'log_items' edit view. Ideally the 'sub-client' select box should populate itself depending upon the 'client' chosen, the 'project' select box should also populate itself depending on the 'sub-client' selected etc, etc. I guess the way to go about populating the select boxes with relevant options is Ajax, but I am unsure of how to go about actually accessing a model from the child view of a indirectly related model, for example how to create a 'sub-client' select box in the 'log_items' edit view. I have have found this example: http://forum.phpsitesolutions.com/php-frameworks/cakephp/ajax-cakephp-dynamically-populate-html-select-dropdown-box-t29.html where someone achieves something similar for US states, counties and cities. However, I noticed in the database schema - which is downloadable from the site above link - that the database tables don't have any foreign keys, so now I'm wondering if I'm going about things in the correct manner. Any pointers and advice would be very much appreciated. Kind regards, Chris

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  • Why does "return ERROR" only work with exceptions?

    - by ThreaT
    In the struts.xml I use: <result name="error">error</result> Then in my action I use: addActionError("ERROR RETURNED"); return ERROR; When I submit the form then it just goes to a blank page and does nothing. However, if I FORCE an exception to be thrown in the action then it goes to the error page and shows the ActionError message. So am I doing this wrong? If so, how should I tell struts to show an error page using "if statements" instead of relying solely on expensive try catches? EDIT 1: I'm using struts 2 version: 2.1.8.1 EDIT 2: For example, here is my action code that I'm using to test: String test = ""; int number = 0; try { if (number == 1) { System.out.println("number 1: " + number); test = SUCCESS; } else if (number == 2) { System.out.println("number 2: " + number); addActionError("ERROR RETURNED?"); addActionMessage("TESTTEST"); test = ERROR; } else if (number == 3) { System.out.println("number 3: " + number); addActionError("ERROR RETURNED?"); addActionMessage("TESTTEST"); test = INPUT; } else { System.out.println("number 4: " + number); test = LOGIN; } } catch (Exception e) { addActionError("ERROR RETURNED? " + e); } return test; And here is my JSP code: <s:form action="number_save" method="post"> <s:textfield name="number" label="Enter number" /> </s:form> <s:actionerror /> <s:fielderror /> <s:actionmessage /> EDIT 3: Here is a longer version of my struts.xml: <action name="number" method="numberCreate" class="NumberActionBean"> <result>number.jsp</result> </action> <action name="error"> <result>error.jsp</result> </action> <action name="number_save" method="numberSave" class="NumberActionBean"> <interceptor-ref name="defaultStack"></interceptor-ref> <result name="success" type="redirect">index</result> <result name="input" type="redirect">number</result> <result name="error">error</result> <result name="login" type="redirect">login</result> <result name="none">number</result> </action> EDIT 4: My error.jsp is simply a <s:actionerror /> tag with the general taglibs and html tags...

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  • UIPageViewController blanking page

    - by CrazyEoin
    I've been trying to use the UIPageViewController to display 3 different nibs for a few days on and off now and have almost got it working. I still have one weird bug that I cant figure out. Basically the app starts, I can scroll between the 3 pages one after another with out any problems, eg: Page1-Page2-Page3 and then back to the start: Page3-Page2-Page1. No Problems. The issue is that if I scroll, for example from Page3-Page2, then BACK to Page3, Page3 Dissappears when it snaps into place. If I scroll to where a forth page would be, then I get Page3. Here is the code relevant to the UIPageViewController, the nibs and the delegate methods for the UIPageViewController: - (void)viewDidLoad{ [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. self.pageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:nil]; self.pageViewController.delegate = self; [[self.pageViewController view] setFrame:[[self view] bounds]]; indexTest = 0; Page1 *p1 = [[Page1 alloc]initWithNibName:@"Page1" bundle:nil]; p1.view.tag = 1; Page2 *p2 = [[Page2 alloc]initWithNibName:@"Page2" bundle:nil]; p2.view.tag = 2; Page3 *p3 = [[Page3 alloc]initWithNibName:@"Page3" bundle:nil]; p3.view.tag = 3; NSArray *arr = [[NSArray alloc] initWithObjects:p1,nil]; viewControllers = [[NSMutableArray alloc] initWithObjects:p1,p2,p3, nil]; [self.pageViewController setViewControllers:arr direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil]; self.pageViewController.dataSource = self; [self addChildViewController:self.pageViewController]; [[self view] addSubview:[self.pageViewController view]]; [self.pageViewController didMoveToParentViewController:self]; self.view.gestureRecognizers = self.pageViewController.gestureRecognizers; } #pragma mark - page view controller stuff - (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController { if (indexTest > 0) { switch (indexTest) { case 1:{ NSLog(@"NO page is BEFORE current page"); break; } case 2:{ NSLog(@"Page BEFORE is Page: %@", [NSString stringWithFormat:@"%@",[viewControllers objectAtIndex:0] ] ); indexTest--; return [viewControllers objectAtIndex:0]; break; } default:{ NSLog(@"PROBLEM in viewBEFORE, indexTest = %d!!!!", indexTest); break; } } } return nil; } - (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController { if (indexTest < NUM_OF_PAGES) { switch (indexTest) { case 0:{ NSLog(@"Page AFTER is Page: %@", [NSString stringWithFormat:@"%@",[viewControllers objectAtIndex:1] ] ); indexTest++; return [viewControllers objectAtIndex:1]; break; } case 1:{ NSLog(@"Page AFTER is Page: %@", [NSString stringWithFormat:@"%@",[viewControllers objectAtIndex:2] ] ); indexTest++; return [viewControllers objectAtIndex:2]; break; } case 2:{ NSLog(@"No pages AFTER this current page %d", indexTest); break; } default:{ NSLog(@"PROBLEM in viewAFTER, indexTest = %d!!!!", indexTest); break; } } } return nil; } Finally the page index dots code #pragma mark - dot controller - (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController { // The number of items reflected in the page indicator. return NUM_OF_PAGES; } - (NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController { // The selected item reflected in the page indicator. return 0; } Any and all help is much appreciated, I think I'm just doing something silly that I cant see as I'm so close to it fully working. If anythings not clear or I haven't give enough information please let me know and I'll answer it as best as I can. Thanks

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  • How to call virtual function of an object in C++

    - by SoonDead
    I'm struggling with calling a virtual function in C++. I'm not experienced in C++, I mainly use C# and Java so I might have some delusions, but bear with me. I have to write a program where I have to avoid dynamic memory allocation if possible. I have made a class called List: template <class T> class List { public: T items[maxListLength]; int length; List() { length = 0; } T get(int i) const { if (i >= 0 && i < length) { return items[i]; } else { throw "Out of range!"; } }; // set the value of an already existing element void set(int i, T p) { if (i >= 0 && i < length) { items[i] = p; } else { throw "Out of range!"; } } // returns the index of the element int add(T p) { if (length >= maxListLength) { throw "Too many points!"; } items[length] = p; return length++; } // removes and returns the last element; T pop() { if (length > 0) { return items[--length]; } else { throw "There is no element to remove!"; } } }; It just makes an array of the given type, and manages the length of it. There is no need for dynamic memory allocation, I can just write: List<Object> objects; MyObject obj; objects.add(obj); MyObject inherits form Object. Object has a virtual function which is supposed to be overridden in MyObject: struct Object { virtual float method(const Input& input) { return 0.0f; } }; struct MyObject: public Object { virtual float method(const Input& input) { return 1.0f; } }; I get the elements as: objects.get(0).method(asdf); The problem is that even though the first element is a MyObject, the Object's method function is called. I'm guessing there is something wrong with storing the object in an array of Objects without dynamically allocating memory for the MyObject, but I'm not sure. Is there a way to call MyObject's method function? How? It's supposed to be a heterogeneous collection btw, so that's why the inheritance is there in the first place. If there is no way to call the MyObject's method function, then how should I make my list in the first place?

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  • Adding Another Parameter to my Custom jQuery Gallery

    - by steve
    My website currently uses a custom jQuery gallery system that I've developed... it works well, but I want to add one capability that I can't seem to figure out. I want the user to, instead of having to click each thumbnail, also be able to click the full image itself to advance in the gallery. Working gallery is here: http://www.studioimbrue.com The code is as follows: $('.thumbscontainer ul li a').click(function() { var li_index = $(this).parents('ul').children('li').index($(this).parent("li"));    $(this).parents('.thumbscontainer').parent().find('.captions ul li').fadeOut(); $(this).parents('.thumbscontainer').parent().find('.captions ul li:eq('+li_index+')').fadeIn(); }); }); and the gallery HTML markup is as follows: <div class="container"> <div class="captions" id="usbdrive"> <ul> <li style="display:block"> <img src="images/portfolio/usbdrive/1.jpg" /> <div class="caption"> <span class='projecttitle'>Super Talent USB Drive Package.</span> A fancy, lavish package designed for Super Talent's specialty USB drive. It was known as the world's smallest flash drive <span class="amp">&amp;</span> it is dipped in gold! </div> </li> <li> <img src="images/portfolio/usbdrive/2.jpg" /> </li> <li> <img src="images/portfolio/usbdrive/3.jpg" /> </li> <li> <img src="images/portfolio/usbdrive/4.jpg" /> </li> <li> <img src="images/portfolio/usbdrive/5.jpg" /> </li> </ul> </div> <div class="thumbscontainer verticalthumbs"> <ul> <li><a href="javascript:void(0);" name="usbdrive1"><img src="images/portfolio/usbdrive/1.jpg" /></a></li> <li><a href="javascript:void(0);" name="usbdrive2"><img src="images/portfolio/usbdrive/2.jpg" /></a></li> <li><a href="javascript:void(0);" name="usbdrive3"><img src="images/portfolio/usbdrive/3.jpg" /></a></li> <li><a href="javascript:void(0);" name="usbdrive4"><img src="images/portfolio/usbdrive/4.jpg" /></a></li> <li><a href="javascript:void(0);" name="usbdrive5"><img src="images/portfolio/usbdrive/5.jpg" /></a></li> </ul> </div> </div>

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  • Jquery only works the first time

    - by Tripping
    I am trying to teach myself general web development skills. I am trying to create a image upload with preview functionality using HTML5 FileAPI. Till now, I have created a file input which shows the preview of image when selected. Html mark up is below: <div> <!-- Photos --> <fieldset> <legend>PropertyPhotos</legend> <div class="upload-box" id="upload-box-1"> <div class="preview-box"> <img alt="Field for image cutting" id="preview_1" src="@Url.Content("~/Content/empty.png")" /> </div> <div> @Html.FileFor(model => model.File1) @Html.ValidationMessageFor(model => model.File1) </div> </div> <div class="upload-box" id="upload-box-2"> <div class="preview-box"> <img alt="Field for image cutting" id="preview_2" src="@Url.Content("~/Content/empty.png")" /> </div> <div> @Html.FileFor(model => model.File2) @Html.ValidationMessageFor(model => model.File2) </div> </div> <div class="upload-box" id="upload-box-3"> <div class="preview-box"> <img alt="Field for image cutting" id="preview_3" src="@Url.Content("~/Content/empty.png")" /> </div> <div> @Html.FileFor(model => model.File3) @Html.ValidationMessageFor(model => model.File3) </div> </div> </fieldset> </div> The Jquery to show preview and then display the next "upload-box" is as follows: <script type="text/javascript"> $(document).ready(function () { // show first box $("#upload-box-1").fadeIn(); //Get current & next step index var stepNum = $('div.upload-box').attr('id').replace(/[^\d]/g, ''); var nextNum = parseInt(stepNum)+1; //Get the preview image tag var preview = $('#preview_'+stepNum); //Load preview on file tag change and display second upload-box $('#File'+stepNum).change(function (evt) { var f = evt.target.files[0]; var reader = new FileReader(); if (!f.type.match('image.*')) { alert("The selected file does not appear to be an image."); return; } reader.onload = function (e) { preview.attr('src', e.target.result); }; reader.readAsDataURL(f); //Show next upload-box $("#upload-box-" + nextNum).fadeIn(); }); }); </script> However, this code only first for the first time ... i.e. on selecting a file - It shows a preview and then shows the next "upload-box". However, when I browse using the second file it doesn't show any preview. From what I have ready, I need to close the Jquery function so that it can be initialised again but I am not sure how to do that. Any help will be grateful.

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  • PHP Form Automatic Submission

    - by sex stevens
    I need to create a PHP script that runs around the clock and re-submits a form without actually loading the form, just sending the same request over and over. I used a program called WireShark to record my packets and play them back using a packet player. This took two hours of troubleshooting and configuring. When everything finally worked, it turns out the end result was a dead end. The packets being sent did not affect anything. This code is what the script needs to resubmit: <a href="#" onclick="_('_tf11').value=15; return false;">(15)</a> <input type="image" id="btn_train" class="dynamic_img" value="ok" name="s1" src="assets/x.gif" alt="Training"> Okay, I know that here on stackoverflow you can't just ask people to do your work. The problem is that I don't even know where to start here. So please at least give me a direction, or a function name or a lead on how to be able to submit this form. Then I'll write a program and you guys can help me finish it if I will need help. here is what I made: The program: <?php //create array of data to be posted $post_data['tf[11]'] = '10000'; $post_data['s1'] = 'ok'; //traverse array and prepare data for posting (key1=value1) foreach ( $post_data as $key => $value) { $post_items[] = $key . '=' . $value; } //create the final string to be posted using implode() $post_string = implode ('&', $post_items); //create cURL connection $curl_connection = curl_init('http://crusadertrav.com/build.php?id=33'); //set options curl_setopt($curl_connection, CURLOPT_CONNECTTIMEOUT, 30); curl_setopt($curl_connection, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"); curl_setopt($curl_connection, CURLOPT_RETURNTRANSFER, true); curl_setopt($curl_connection, CURLOPT_SSL_VERIFYPEER, false); curl_setopt($curl_connection, CURLOPT_FOLLOWLOCATION, 1); //set data to be posted curl_setopt($curl_connection, CURLOPT_POSTFIELDS, $post_string); //perform our request $result = curl_exec($curl_connection); //show information regarding the request print_r(curl_getinfo($curl_connection)); echo curl_errno($curl_connection) . '-' . curl_error($curl_connection); //close the connection curl_close($curl_connection); ?> The forms: <input type="text" class="text" id="_tf11" name="tf[11]" value="0" maxlength="4"> <input type="image" id="btn_train" class="dynamic_img" value="ok" name="s1" src="assets/x.gif" alt="Training"> The result: Array ( [url] => http://crusadertrav.com/index.php [content_type] => text/html; charset=UTF-8 [http_code] => 200 [header_size] => 895 [request_size] => 350 [filetime] => -1 [ssl_verify_result] => 0 [redirect_count] => 1 [total_time] => 2.781 [namelookup_time] => 0 [connect_time] => 0.532 [pretransfer_time] => 0.532 [size_upload] => 0 [size_download] => 10655 [speed_download] => 3831 [speed_upload] => 0 [download_content_length] => 0 [upload_content_length] => 0 [starttransfer_time] => 0.954 [redirect_time] => 0.906 [certinfo] => Array ( ) [primary_ip] => 5.154.88.71 [primary_port] => 80 [local_ip] => 192.168.11.52 [local_port] => 3222 [redirect_url] => ) 0-

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  • jQuery .find() doesn't return data in IE but does in Firefox and Chrome

    - by Steve Hiner
    I helped a friend out by doing a little web work for him. Part of what he needed was an easy way to change a couple pieces of text on his site. Rather than having him edit the HTML I decided to provide an XML file with the messages in it and I used jQuery to pull them out of the file and insert them into the page. It works great... In Firefox and Chrome, not so great in IE7. I was hoping one of you could tell me why. I did a fair but of googling but couldn't find what I'm looking for. Here's the XML: <?xml version="1.0" encoding="utf-8" ?> <messages> <message type="HeaderMessage"> This message is put up in the header area. </message> <message type="FooterMessage"> This message is put in the lower left cell. </message> </messages> And here's my jQuery call: <script type="text/javascript"> $(document).ready(function() { $.get('messages.xml', function(d) { //I have confirmed that it gets to here in IE //and it has the xml loaded. //alert(d); gives me a message box with the xml text in it //alert($(d).find('message')); gives me "[object Object]" //alert($(d).find('message')[0]); gives me "undefined" //alert($(d).find('message').Length); gives me "undefined" $(d).find('message').each(function() { //But it never gets to here in IE var $msg = $(this); var type = $msg.attr("type"); var message = $msg.text(); switch (type) { case "HeaderMessage": $("#HeaderMessageDiv").html(message); break; case "FooterMessage": $("#footermessagecell").html(message); break; default: } }); }); }); </script> Is there something I need to do differently in IE? Based on the message box with [object Object] I'm assumed that .find was working in IE but since I can't index into the array with [0] or check it's Length I'm guessing that means .find isn't returning any results. Any reason why that would work perfectly in Firefox and Chrome but fail in IE? I'm a total newbie with jQuery so I hope I haven't just done something stupid. That code above was scraped out of a forum and modified to suit my needs. Since jQuery is cross-platform I figured I wouldn't have to deal with this mess. Edit: I've found that if I load the page in Visual Studio 2008 and run it then it will work in IE. So it turns out it always works when run through the development web server. Now I'm thinking IE just doesn't like doing .find in XML loaded off of my local drive so maybe when this is on an actual web server it will work OK. I have confirmed that it works fine when browsed from a web server. Must be a peculiarity with IE. I'm guessing it's because the web server sets the mime type for the xml data file transfer and without that IE doesn't parse the xml correctly.

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  • Drop down list in menu disappears before able to click

    - by user1834770
    I've had quite a search through forums looking for a solution for this, but since I don't know coding I'm not sure what applies to me and what doesn't. So, apologies if this is an often solved problem, but I'll greatly appreciate your help! After much trial and error, I've managed to get a drop down list of pages on my navigation bar; however, when I go to click on a sub-page, the entire menu disappears. I've read through other similar problems where there has been an issue with a margin that's too big, but I think my margins are set to '0'. The blog is at: http://swirlstwirlsblog.blogspot.com.au/ I haven't got content in the sub pages but there are there and linked in the html/javascript widget. I've also looked at it in Chrome, Mozilla, and Safari and it's the same issue. I'm also not sure if this is a javascript, css, or html problem, so please be kind in your responses--I'm only new! Thanks so much to anyone able to help me on this. Here's the script I used in the Widget: <ul id="jsddm"> <li><a href="http://swirlstwirlsblog.blogspot.com.au/">Home</a> <li><a href="http://swirlstwirlsblog.blogspot.com.au/search/label/sparkles">Sparkles</a> </li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/search/label/friendship">Friendship</a> </li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/search/label/humour">Humour</a> </li> <li><a href="">About</a> <ul> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/about_16.html">Us</a></li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/contributers.html">Contributors</a> </li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/advertising.html">Advertising</a> </li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/privacy-policies.html">Privacy</a></li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/contact.html">Contact</a></li> </ul> </li> </li></ul> And here's the html code I put in the template: <pre>#jsddm { margin: 0; padding: 15px; z-index:1000000000; position:relative; } #jsddm li { float: left; list-style: none; font: 12px Tahoma, Arial; } #jsddm li a { display: block; white-space: nowrap; margin:1px 3px; padding: 5px 10px; border-right: 1px color: eeeeee; text-shadow: #ffffff 0 1px 0; color: #363636; font-size: 15px; font-family: crushed; text-decoration: none; vertical-align: middle; } #jsddm li a:hover { background: #C8C8C8; } #jsddm li ul { margin: 0; padding: 0; position: absolute; visibility: hidden; border-top: 1px solid white; } #jsddm li ul li { float: none; display: inline; } #jsddm li ul li a { width: auto; background: #ffffff; } #jsddm li ul li a:hover { background: #eeeeee; }</pre>

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  • Jquery mobile ajax request not working after 4-5 request is made in Android

    - by Coder_sLaY
    I am developing an application using jQuery mobile 1.1.0 RC1 and phonegap 1.5.0 I have a single HTML page which contains all the pages in it as a div(through data-role="page") here is my code <!DOCTYPE HTML> <html> <head> <title>Index Page</title> <!-- Adding viewport --> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1"> <!-- Adding Phonegap scripts --> <script type="text/javascript" charset="utf-8" src="cordova/cordova-1.5.0.js"></script> <!-- Adding jQuery mobile and jQuery scripts & CSS --> <script type="text/javascript" src="jquery/jquery-1.7.1.min.js"></script> <link rel="stylesheet" href="jquerymobile/jquery.mobile-1.1.0-rc.1.min.css" /> <script type="text/javascript" src="jquery/jquery.validate.min.js"></script> <script type="text/javascript" src="jquerymobile/jquery.mobile-1.1.0-rc.1.min.js"></script> <link rel="stylesheet" href="css/colors.css"> <script type="text/javascript"> function page1(){ $.mobile.changePage("#page2", { transition : "slide" }); } function page2(){ $.mobile.changePage("#page1", { transition : "slide" }); } $("#page1").live("pageshow", function(e) { $.ajax({ type : 'GET', cache : false, url : "http://192.168.1.198:9051/something.xml" + "?time=" + Date.now(), data : { key : "value" }, dataType : "xml", success : function(xml) { console.log("Success Page1"); }, error : function(xhr) { } }); }); $("#page2").live("pageshow", function(e) { $.ajax({ type : 'GET', cache : false, url : "http://192.168.1.198:9051/something.xml" + "?time=" + Date.now(), data : { key : "value" }, dataType : "xml", success : function(xml) { console.log("Success Page2"); }, error : function(xhr) { } }); }); </script> <body> <div data-role="page" id="page1"> <div data-role="header">Page 1</div> <div data-role="content"> <input type="text" name="page1GetTime" id="page1GetTime" value="" /><a href="#" data-role="button" onclick="page1()" id="gotopage2"> Go to Page 2 </a> </div> </div> <div data-role="page" id="page2"> <div data-role="header">Page 2</div> <div data-role="content"> <input type="text" name="page2GetTime" id="page2GetTime" value="" /><a href="#" data-role="button" onclick="page2()" id="gotopage1">Go to Page 1</a> </div> </div> </body> Now when i click to "Go to page2" then page2 will be shown along with one ajax request .. If i keep on moving from one page to another then a ajax request is made.. This request stops responding after 4 to 5 request... Why is it happening?

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  • jQuery embedding youtube IE issue

    - by webmonkey237
    I have been working on a custom image slider featured here: JQuery $(function(){ $('.cont:gt(0)').hide(); $("#parent").on("mouseenter", ".extraContent div", function(){ var ind = $(this).index(); $("#parent").find(".cont").stop().fadeTo(600,0,function(){ $('#parent').find('.cont').eq(ind).stop().fadeTo(300,1); }); }); $('#parent .extraContent').on('click',function(){ window.location=$(this).find("a").attr("href"); return false; }); }); CSS ?#parent { width:400px; margin:auto} .mainContent { width:430px; height:300px; border:1px solid #000;padding:5px; } .extraContent {overflow:auto; width:450px;} .extraContent div{float:left; width:90px; height:90px; border:1px solid #00F; margin:5px; padding:5px } .extraContent div:hover { border:1px solid #0F0;cursor:pointer } .cont{ position:absolute; } HTML <div id="parent"> <div class="mainContent"> <div class="cont"> Content 1....</div> <div class="cont"> Content 2....</div> <div class="cont">Content 3...<br /><iframe width="267" height="200" src="http://www.youtube.com/embed/6tlQn7iePV4?rel=0" frameborder="0" allowfullscreen></iframe></div> <div class="cont"> Content 4....</div> </div> <div class="extraContent"> <div><p>1 Custom content here <br /> <a href="">Some link</a></p></div> <div><p>2 Custom content here <br /> <a href="">Some link</a></p></div> <div><p>3 Custom content here <br /> <a href="">Some link</a></p></div> <div><p>4 Custom content here <br /> <a href="">Some link</a></p></div> </div> </div>? My problem is if I embed YouTube video straight from the site using there iframe it transitions fine in Chrome but Firefox & IE just display the video straight away and each slide/div appears under the video, is this a known problem and doesn't anyone know a way I can get IE & FF to behave. p.s. because this is going to be in a content management system the only way the user can embed the video is using the default code from youtube. FIDDLE HERE

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  • C - Error with read() of a file, storage in an array, and printing output properly

    - by ns1
    I am new to C, so I am not exactly sure where my error is. However, I do know that the great portion of the issue lies either in how I am storing the doubles in the d_buffer (double) array or the way I am printing it. Specifically, my output keeps printing extremely large numbers (with around 10-12 digits before the decimal point and a trail of zeros after it. Additionally, this is an adaptation of an older program to allow for double inputs, so I only really added the two if statements (in the "read" for loop and the "printf" for loop) and the d_buffer declaration. I would appreciate any input whatsoever as I have spent several hours on this error. #include <stdio.h> #include <fcntl.h> #include <sys/types.h> #include <unistd.h> #include <string.h> struct DataDescription { char fieldname[30]; char fieldtype; int fieldsize; }; /* ----------------------------------------------- eof(fd): returns 1 if file `fd' is out of data ----------------------------------------------- */ int eof(int fd) { char c; if ( read(fd, &c, 1) != 1 ) return(1); else { lseek(fd, -1, SEEK_CUR); return(0); } } void main() { FILE *fp; /* Used to access meta data */ int fd; /* Used to access user data */ /* ---------------------------------------------------------------- Variables to hold the description of the data - max 10 fields ---------------------------------------------------------------- */ struct DataDescription DataDes[10]; /* Holds data descriptions for upto 10 fields */ int n_fields; /* Actual # fields */ /* ------------------------------------------------------ Variables to hold the data - max 10 fields.... ------------------------------------------------------ */ char c_buffer[10][100]; /* For character data */ int i_buffer[10]; /* For integer data */ double d_buffer[10]; int i, j; int found; printf("Program for searching a mini database:\n"); /* ============================= Read in meta information ============================= */ fp = fopen("db-description", "r"); n_fields = 0; while ( fscanf(fp, "%s %c %d", DataDes[n_fields].fieldname, &DataDes[n_fields].fieldtype, &DataDes[n_fields].fieldsize) > 0 ) n_fields++; /* --- Prints meta information --- */ printf("\nThe database consists of these fields:\n"); for (i = 0; i < n_fields; i++) printf("Index %d: Fieldname `%s',\ttype = %c,\tsize = %d\n", i, DataDes[i].fieldname, DataDes[i].fieldtype, DataDes[i].fieldsize); printf("\n\n"); /* --- Open database file --- */ fd = open("db-data", O_RDONLY); /* --- Print content of the database file --- */ printf("\nThe database content is:\n"); while ( ! eof(fd) ) { /* ------------------ Read next record ------------------ */ for (j = 0; j < n_fields; j++) { if ( DataDes[j].fieldtype == 'I' ) read(fd, &i_buffer[j], DataDes[j].fieldsize); if ( DataDes[j].fieldtype == 'F' ) read(fd, &d_buffer[j], DataDes[j].fieldsize); if ( DataDes[j].fieldtype == 'C' ) read(fd, &c_buffer[j], DataDes[j].fieldsize); } double d; /* ------------------ Print it... ------------------ */ for (j = 0; j < n_fields; j++) { if ( DataDes[j].fieldtype == 'I' ) printf("%d ", i_buffer[j]); if ( DataDes[j].fieldtype == 'F' ) d = d_buffer[j]; printf("%lf ", d); if ( DataDes[j].fieldtype == 'C' ) printf("%s ", c_buffer[j]); } printf("\n"); } printf("\n"); printf("\n"); } Post edits output: 16777216 0.000000 107245694331284094976.000000 107245694331284094976.000000 Pi 33554432 107245694331284094976.000000 2954938175610156848888276006519501238173891974277081114627768841840801736306392481516295906896346039950625609765296207682724801406770458881439696544971142710292689518104183685723154223544599940711614138798312668264956190761622328617992192.000000 2954938175610156848888276006519501238173891974277081114627768841840801736306392481516295906896346039950625609765296207682724801406770458881439696544971142710292689518104183685723154223544599940711614138798312668264956190761622328617992192.000000 Secret Key 50331648 2954938175610156848888276006519501238173891974277081114627768841840801736306392481516295906896346039950625609765296207682724801406770458881439696544971142710292689518104183685723154223544599940711614138798312668264956190761622328617992192.000000 -0.000000 -0.000000 The number E Expected Output: 3 rows of data ending with the number "e = 2.18281828" To reproduce the problem, the following two files need to be in the same directory as the lookup-data.c file: - db-data - db-description

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  • Java: Object Array assignment in for loop

    - by Hackster
    I am trying to use Dijkstra's algorithm to find the shortest path from a specific vertex (v0) to the rest of them. That is solved and works well with this code from this link below: http://en.literateprograms.org/index.php?title=Special:DownloadCode/Dijkstra%27s_algorithm_(Java)&oldid=15444 I am having trouble with assigning the Edge array in a for loop from the user input, as opposed to hard-coding it like it is here. Any help assigning a new edge to Edge[] adjacencies from each vertex? Keeping in mind it could be 1 or multiple edges. class Vertex implements Comparable<Vertex> { public final String name; public Edge[] adjacencies; public double minDistance = Double.POSITIVE_INFINITY; public Vertex previous; public Vertex(String argName) { name = argName; } public String toString() { return name; } public int compareTo(Vertex other){ return Double.compare(minDistance, other.minDistance); } } class Edge{ public final Vertex target; public final double weight; public Edge(Vertex argTarget, double argWeight){ target = argTarget; weight = argWeight; } } public static void main(String[] args) { Vertex v[] = new Vertex[3]; Vertex v[0] = new Vertex("Harrisburg"); Vertex v[1] = new Vertex("Baltimore"); Vertex v[2] = new Vertex("Washington"); v0.adjacencies = new Edge[]{ new Edge(v[1], 1), new Edge(v[2], 3) }; v1.adjacencies = new Edge[]{ new Edge(v[0], 1), new Edge(v[2], 1),}; v2.adjacencies = new Edge[]{ new Edge(v[0], 3), new Edge(v[1], 1) }; Vertex[] vertices = { v0, v1, v2}; /*Three vertices with weight: V0 connects (V1,1),(V2,3) V1 connects (V0,1),(V2,1) V2 connects (V1,1),(V2,3) */ computePaths(v0); for (Vertex v : vertices){ System.out.println("Distance to " + v + ": " + v.minDistance); List<Vertex> path = getShortestPathTo(v); System.out.println("Path: " + path); } } } The above code works well in finding the shortest path from v0 to all the other vertices. The problem occurs when assigning the new edge[] to edge[] adjacencies. For example this does not produce the correct output: for (int i = 0; i < total_vertices; i++){ s = br.readLine(); char[] line = s.toCharArray(); for (int j = 0; j < line.length; j++){ if(j % 4 == 0 ){ //Input: vertex weight vertex weight: 1 1 2 3 int vert = Integer.parseInt(String.valueOf(line[j])); int w = Integer.parseInt(String.valueOf(line[j+2])); v[i].adjacencies = new Edge[] {new Edge(v[vert], w)}; } } } As opposed to this: v0.adjacencies = new Edge[]{ new Edge(v[1], 1), new Edge(v[2], 3) }; How can I take the user input and make an Edge[], to pass it to adjacencies? The problem is it could be 0 edges or many. Any help would be much appreciated Thanks!

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  • Having trouble with multiple Jquery libraries

    - by user3716971
    I've seen the posts about the no conflict but I'm not very code savvy and can't figure it out alone. I'm having trouble making two libraries work together. At the top I have the 1.9.1 library which controls a news ticker, and a carousel. Near the bottom there is a library 1.6.1, which controls a Dribbble feed. If I remove 1.6.1 everything but the dribbble feed works, and if I remove the 1.9.1 the dribbble feed is the only thing that works. I uploaded the website for you guys to check out. If you could edit my code to make it work that would be amazing, I don't have much knowledge of jquery. This version has a working dribbble feed at the very bottom http://michaelcullenbenson.com/MichaelCullenBenson.com/index.html and this version has a broken feed and everything else works. http://michaelcullenbenson.com/MichaelCullenBenson.com/index2.html Help would be AMAZING as the dribbble feed is the last element I'm trying to finish on my homepage and I'll be able to move on. <script type="text/javascript" src="js/jquery-1.9.1.min.js"></script> <script type="text/javascript" src="js/jquery.innerfade.js"></script> <script type="text/javascript"> $(document).ready( function(){ $('#news').innerfade({ animationtype: 'slide', speed: 600, timeout: 6000, type: 'random', containerheight: '1em' }); }); </script> <!-- Include all compiled plugins (below), or include individual files as needed --> <script src="utilcarousel-files/utilcarousel/jquery.utilcarousel.min.js"></script> <script src="utilcarousel-files/magnific-popup/jquery.magnific-popup.js"></script> <script src="js/responsive-nav.js"></script> <script> $(function() { $('#fullwidth').utilCarousel({ breakPoints : [[600, 1], [800, 2], [1000, 3], [1300, 4],], mouseWheel : false, rewind : true, autoPlay : true, pagination : false }); $('#fullwidth2').utilCarousel({ breakPoints : [[600, 1], [800, 2], [1000, 3], [1300, 4],], mouseWheel : false, rewind : true, autoPlay : true, pagination : false }); }); </script> <script> $(document).ready(function() { var movementStrength = 25; var height = movementStrength / $(window).height(); var width = movementStrength / $(window).width(); $("#aboutarea").mousemove(function(e){ var pageX = e.pageX - ($(window).width() / 2); var pageY = e.pageY - ($(window).height() / 2); var newvalueX = width * pageX * -1 - 25; var newvalueY = height * pageY * -1 - 50; $('#aboutarea').css("background-position", newvalueX+"px "+newvalueY+"px"); }); }); </script> <script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js" type="text/javascript"></script> <script type="text/javascript" src="dribbble.js"></script> <script type="text/javascript"> $(function () { $('#user').dribbble({ player: 'MCBDesign', total: 1 }); }); </script>

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  • HTML/CSS - No 100% height on div in IE

    - by Jordan Rynard
    Okay, so I've got a problem - and I'd love to have it fixed. I am using my favourite way of setting up a simple header/content/footer layout. The problem is that any elements I add to the 'content' div of my layout can not be expanded to 100% in Internet Explorer (as far as I know, IE only). I understand there is no height declared to the 'content' element, but because of the style of its positioning (declaring an absolute top AND bottom), the element fills the desired area. (The content element has a background color defined so you can see that the div is in fact filling between both the header and the footer.) So my problem is, since the div is clearly expanded between the two, why can't a child be set to 100% to fill that area? If anyone has any solutions, I'd love to hear them. (I'm looking for a solution that won't involve designing by an entire different layout.. or at least perhaps an explanation of why this is happening. I'm assuming at this point it's because of the lack of a height declaration -- but the div is expanded, so I don't get it!) You can view a page of the example here: http://www.elizabethlouter.com/html/index.html And here is the code as used on the page: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta name="robots" content="noindex" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>No 100% height on 'content' child div in IE</title> </head> <style> html, body { width:100%; height:100%; margin:0px; padding:0px; } body { position:relative; } #wrapper { position:absolute; top:0px; width:960px; height:100%; left:50%; margin-left:-480px; } #header{ position:absolute; top:0px; left:0px; width:100%; height:200px; background-color:#999; } #content{ position:absolute; top:100px; bottom:50px; left:0px; width:100%; background-color:#F7F7F7; } #content_1{ width:200px; background-color:black; height:100%; } #footer{ position:absolute; bottom:0px; left:0px; width:100%; height:50px; background-color:#999; } </style> <body> <div id="wrapper"> <div id="header"> </div> <div id="content"> <div id="content_1"> </div> </div> <div id="footer"> </div> </div> </body> </html>

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  • Using LINQ Distinct: With an Example on ASP.NET MVC SelectListItem

    - by Joe Mayo
    One of the things that might be surprising in the LINQ Distinct standard query operator is that it doesn’t automatically work properly on custom classes. There are reasons for this, which I’ll explain shortly. The example I’ll use in this post focuses on pulling a unique list of names to load into a drop-down list. I’ll explain the sample application, show you typical first shot at Distinct, explain why it won’t work as you expect, and then demonstrate a solution to make Distinct work with any custom class. The technologies I’m using are  LINQ to Twitter, LINQ to Objects, Telerik Extensions for ASP.NET MVC, ASP.NET MVC 2, and Visual Studio 2010. The function of the example program is to show a list of people that I follow.  In Twitter API vernacular, these people are called “Friends”; though I’ve never met most of them in real life. This is part of the ubiquitous language of social networking, and Twitter in particular, so you’ll see my objects named accordingly. Where Distinct comes into play is because I want to have a drop-down list with the names of the friends appearing in the list. Some friends are quite verbose, which means I can’t just extract names from each tweet and populate the drop-down; otherwise, I would end up with many duplicate names. Therefore, Distinct is the appropriate operator to eliminate the extra entries from my friends who tend to be enthusiastic tweeters. The sample doesn’t do anything with the drop-down list and I leave that up to imagination for what it’s practical purpose could be; perhaps a filter for the list if I only want to see a certain person’s tweets or maybe a quick list that I plan to combine with a TextBox and Button to reply to a friend. When the program runs, you’ll need to authenticate with Twitter, because I’m using OAuth (DotNetOpenAuth), for authentication, and then you’ll see the drop-down list of names above the grid with the most recent tweets from friends. Here’s what the application looks like when it runs: As you can see, there is a drop-down list above the grid. The drop-down list is where most of the focus of this article will be. There is some description of the code before we talk about the Distinct operator, but we’ll get there soon. This is an ASP.NET MVC2 application, written with VS 2010. Here’s the View that produces this screen: <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<TwitterFriendsViewModel>" %> <%@ Import Namespace="DistinctSelectList.Models" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">     Home Page </asp:Content><asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">     <fieldset>         <legend>Twitter Friends</legend>         <div>             <%= Html.DropDownListFor(                     twendVM => twendVM.FriendNames,                     Model.FriendNames,                     "<All Friends>") %>         </div>         <div>             <% Html.Telerik().Grid<TweetViewModel>(Model.Tweets)                    .Name("TwitterFriendsGrid")                    .Columns(cols =>                     {                         cols.Template(col =>                             { %>                                 <img src="<%= col.ImageUrl %>"                                      alt="<%= col.ScreenName %>" />                         <% });                         cols.Bound(col => col.ScreenName);                         cols.Bound(col => col.Tweet);                     })                    .Render(); %>         </div>     </fieldset> </asp:Content> As shown above, the Grid is from Telerik’s Extensions for ASP.NET MVC. The first column is a template that renders the user’s Avatar from a URL provided by the Twitter query. Both the Grid and DropDownListFor display properties that are collections from a TwitterFriendsViewModel class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { /// /// For finding friend info on screen /// public class TwitterFriendsViewModel { /// /// Display names of friends in drop-down list /// public List FriendNames { get; set; } /// /// Display tweets in grid /// public List Tweets { get; set; } } } I created the TwitterFreindsViewModel. The two Lists are what the View consumes to populate the DropDownListFor and Grid. Notice that FriendNames is a List of SelectListItem, which is an MVC class. Another custom class I created is the TweetViewModel (the type of the Tweets List), shown below: namespace DistinctSelectList.Models { /// /// Info on friend tweets /// public class TweetViewModel { /// /// User's avatar /// public string ImageUrl { get; set; } /// /// User's Twitter name /// public string ScreenName { get; set; } /// /// Text containing user's tweet /// public string Tweet { get; set; } } } The initial Twitter query returns much more information than we need for our purposes and this a special class for displaying info in the View.  Now you know about the View and how it’s constructed. Let’s look at the controller next. The controller for this demo performs authentication, data retrieval, data manipulation, and view selection. I’ll skip the description of the authentication because it’s a normal part of using OAuth with LINQ to Twitter. Instead, we’ll drill down and focus on the Distinct operator. However, I’ll show you the entire controller, below,  so that you can see how it all fits together: using System.Linq; using System.Web.Mvc; using DistinctSelectList.Models; using LinqToTwitter; namespace DistinctSelectList.Controllers { [HandleError] public class HomeController : Controller { private MvcOAuthAuthorization auth; private TwitterContext twitterCtx; /// /// Display a list of friends current tweets /// /// public ActionResult Index() { auth = new MvcOAuthAuthorization(InMemoryTokenManager.Instance, InMemoryTokenManager.AccessToken); string accessToken = auth.CompleteAuthorize(); if (accessToken != null) { InMemoryTokenManager.AccessToken = accessToken; } if (auth.CachedCredentialsAvailable) { auth.SignOn(); } else { return auth.BeginAuthorize(); } twitterCtx = new TwitterContext(auth); var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); var twendsVM = new TwitterFriendsViewModel { Tweets = friendTweets, FriendNames = friendNames }; return View(twendsVM); } public ActionResult About() { return View(); } } } The important part of the listing above are the LINQ to Twitter queries for friendTweets and friendNames. Both of these results are used in the subsequent population of the twendsVM instance that is passed to the view. Let’s dissect these two statements for clarification and focus on what is happening with Distinct. The query for friendTweets gets a list of the 20 most recent tweets (as specified by the Twitter API for friend queries) and performs a projection into the custom TweetViewModel class, repeated below for your convenience: var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); The LINQ to Twitter query above simplifies what we need to work with in the View and the reduces the amount of information we have to look at in subsequent queries. Given the friendTweets above, the next query performs another projection into an MVC SelectListItem, which is required for binding to the DropDownList.  This brings us to the focus of this blog post, writing a correct query that uses the Distinct operator. The query below uses LINQ to Objects, querying the friendTweets collection to get friendNames: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); The above implementation of Distinct seems normal, but it is deceptively incorrect. After running the query above, by executing the application, you’ll notice that the drop-down list contains many duplicates.  This will send you back to the code scratching your head, but there’s a reason why this happens. To understand the problem, we must examine how Distinct works in LINQ to Objects. Distinct has two overloads: one without parameters, as shown above, and another that takes a parameter of type IEqualityComparer<T>.  In the case above, no parameters, Distinct will call EqualityComparer<T>.Default behind the scenes to make comparisons as it iterates through the list. You don’t have problems with the built-in types, such as string, int, DateTime, etc, because they all implement IEquatable<T>. However, many .NET Framework classes, such as SelectListItem, don’t implement IEquatable<T>. So, what happens is that EqualityComparer<T>.Default results in a call to Object.Equals, which performs reference equality on reference type objects.  You don’t have this problem with value types because the default implementation of Object.Equals is bitwise equality. However, most of your projections that use Distinct are on classes, just like the SelectListItem used in this demo application. So, the reason why Distinct didn’t produce the results we wanted was because we used a type that doesn’t define its own equality and Distinct used the default reference equality. This resulted in all objects being included in the results because they are all separate instances in memory with unique references. As you might have guessed, the solution to the problem is to use the second overload of Distinct that accepts an IEqualityComparer<T> instance. If you were projecting into your own custom type, you could make that type implement IEqualityComparer<T>, but SelectListItem belongs to the .NET Framework Class Library.  Therefore, the solution is to create a custom type to implement IEqualityComparer<T>, as in the SelectListItemComparer class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { public class SelectListItemComparer : EqualityComparer { public override bool Equals(SelectListItem x, SelectListItem y) { return x.Value.Equals(y.Value); } public override int GetHashCode(SelectListItem obj) { return obj.Value.GetHashCode(); } } } The SelectListItemComparer class above doesn’t implement IEqualityComparer<SelectListItem>, but rather derives from EqualityComparer<SelectListItem>. Microsoft recommends this approach for consistency with the behavior of generic collection classes. However, if your custom type already derives from a base class, go ahead and implement IEqualityComparer<T>, which will still work. EqualityComparer is an abstract class, that implements IEqualityComparer<T> with Equals and GetHashCode abstract methods. For the purposes of this application, the SelectListItem.Value property is sufficient to determine if two items are equal.   Since SelectListItem.Value is type string, the code delegates equality to the string class. The code also delegates the GetHashCode operation to the string class.You might have other criteria in your own object and would need to define what it means for your object to be equal. Now that we have an IEqualityComparer<SelectListItem>, let’s fix the problem. The code below modifies the query where we want distinct values: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct(new SelectListItemComparer()) .ToList(); Notice how the code above passes a new instance of SelectListItemComparer as the parameter to the Distinct operator. Now, when you run the application, the drop-down list will behave as you expect, showing only a unique set of names. In addition to Distinct, other LINQ Standard Query Operators have overloads that accept IEqualityComparer<T>’s, You can use the same techniques as shown here, with SelectListItemComparer, with those other operators as well. Now you know how to resolve problems with getting Distinct to work properly and also have a way to fix problems with other operators that require equality comparisons. @JoeMayo

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  • Agile Development

    - by James Oloo Onyango
    Alot of literature has and is being written about agile developement and its surrounding philosophies. In my quest to find the best way to express the importance of agile methodologies, i have found Robert C. Martin's "A Satire Of Two Companies" to be both the most concise and thorough! Enjoy the read! Rufus Inc Project Kick Off Your name is Bob. The date is January 3, 2001, and your head still aches from the recent millennial revelry. You are sitting in a conference room with several managers and a group of your peers. You are a project team leader. Your boss is there, and he has brought along all of his team leaders. His boss called the meeting. "We have a new project to develop," says your boss's boss. Call him BB. The points in his hair are so long that they scrape the ceiling. Your boss's points are just starting to grow, but he eagerly awaits the day when he can leave Brylcream stains on the acoustic tiles. BB describes the essence of the new market they have identified and the product they want to develop to exploit this market. "We must have this new project up and working by fourth quarter October 1," BB demands. "Nothing is of higher priority, so we are cancelling your current project." The reaction in the room is stunned silence. Months of work are simply going to be thrown away. Slowly, a murmur of objection begins to circulate around the conference table.   His points give off an evil green glow as BB meets the eyes of everyone in the room. One by one, that insidious stare reduces each attendee to quivering lumps of protoplasm. It is clear that he will brook no discussion on this matter. Once silence has been restored, BB says, "We need to begin immediately. How long will it take you to do the analysis?" You raise your hand. Your boss tries to stop you, but his spitwad misses you and you are unaware of his efforts.   "Sir, we can't tell you how long the analysis will take until we have some requirements." "The requirements document won't be ready for 3 or 4 weeks," BB says, his points vibrating with frustration. "So, pretend that you have the requirements in front of you now. How long will you require for analysis?" No one breathes. Everyone looks around to see whether anyone has some idea. "If analysis goes beyond April 1, we have a problem. Can you finish the analysis by then?" Your boss visibly gathers his courage: "We'll find a way, sir!" His points grow 3 mm, and your headache increases by two Tylenol. "Good." BB smiles. "Now, how long will it take to do the design?" "Sir," you say. Your boss visibly pales. He is clearly worried that his 3 mms are at risk. "Without an analysis, it will not be possible to tell you how long design will take." BB's expression shifts beyond austere.   "PRETEND you have the analysis already!" he says, while fixing you with his vacant, beady little eyes. "How long will it take you to do the design?" Two Tylenol are not going to cut it. Your boss, in a desperate attempt to save his new growth, babbles: "Well, sir, with only six months left to complete the project, design had better take no longer than 3 months."   "I'm glad you agree, Smithers!" BB says, beaming. Your boss relaxes. He knows his points are secure. After a while, he starts lightly humming the Brylcream jingle. BB continues, "So, analysis will be complete by April 1, design will be complete by July 1, and that gives you 3 months to implement the project. This meeting is an example of how well our new consensus and empowerment policies are working. Now, get out there and start working. I'll expect to see TQM plans and QIT assignments on my desk by next week. Oh, and don't forget that your crossfunctional team meetings and reports will be needed for next month's quality audit." "Forget the Tylenol," you think to yourself as you return to your cubicle. "I need bourbon."   Visibly excited, your boss comes over to you and says, "Gosh, what a great meeting. I think we're really going to do some world shaking with this project." You nod in agreement, too disgusted to do anything else. "Oh," your boss continues, "I almost forgot." He hands you a 30-page document. "Remember that the SEI is coming to do an evaluation next week. This is the evaluation guide. You need to read through it, memorize it, and then shred it. It tells you how to answer any questions that the SEI auditors ask you. It also tells you what parts of the building you are allowed to take them to and what parts to avoid. We are determined to be a CMM level 3 organization by June!"   You and your peers start working on the analysis of the new project. This is difficult because you have no requirements. But from the 10-minute introduction given by BB on that fateful morning, you have some idea of what the product is supposed to do.   Corporate process demands that you begin by creating a use case document. You and your team begin enumerating use cases and drawing oval and stick diagrams. Philosophical debates break out among the team members. There is disagreement as to whether certain use cases should be connected with <<extends>> or <<includes>> relationships. Competing models are created, but nobody knows how to evaluate them. The debate continues, effectively paralyzing progress.   After a week, somebody finds the iceberg.com Web site, which recommends disposing entirely of <<extends>> and <<includes>> and replacing them with <<precedes>> and <<uses>>. The documents on this Web site, authored by Don Sengroiux, describes a method known as stalwart-analysis, which claims to be a step-by-step method for translating use cases into design diagrams. More competing use case models are created using this new scheme, but again, people can't agree on how to evaluate them. The thrashing continues. More and more, the use case meetings are driven by emotion rather than by reason. If it weren't for the fact that you don't have requirements, you'd be pretty upset by the lack of progress you are making. The requirements document arrives on February 15. And then again on February 20, 25, and every week thereafter. Each new version contradicts the previous one. Clearly, the marketing folks who are writing the requirements, empowered though they might be, are not finding consensus.   At the same time, several new competing use case templates have been proposed by the various team members. Each template presents its own particularly creative way of delaying progress. The debates rage on. On March 1, Prudence Putrigence, the process proctor, succeeds in integrating all the competing use case forms and templates into a single, all-encompassing form. Just the blank form is 15 pages long. She has managed to include every field that appeared on all the competing templates. She also presents a 159- page document describing how to fill out the use case form. All current use cases must be rewritten according to the new standard.   You marvel to yourself that it now requires 15 pages of fill-in-the-blank and essay questions to answer the question: What should the system do when the user presses Return? The corporate process (authored by L. E. Ott, famed author of "Holistic Analysis: A Progressive Dialectic for Software Engineers") insists that you discover all primary use cases, 87 percent of all secondary use cases, and 36.274 percent of all tertiary use cases before you can complete analysis and enter the design phase. You have no idea what a tertiary use case is. So in an attempt to meet this requirement, you try to get your use case document reviewed by the marketing department, which you hope will know what a tertiary use case is.   Unfortunately, the marketing folks are too busy with sales support to talk to you. Indeed, since the project started, you have not been able to get a single meeting with marketing, which has provided a never-ending stream of changing and contradictory requirements documents.   While one team has been spinning endlessly on the use case document, another team has been working out the domain model. Endless variations of UML documents are pouring out of this team. Every week, the model is reworked.   The team members can't decide whether to use <<interfaces>> or <<types>> in the model. A huge disagreement has been raging on the proper syntax and application of OCL. Others on the team just got back from a 5-day class on catabolism, and have been producing incredibly detailed and arcane diagrams that nobody else can fathom.   On March 27, with one week to go before analysis is to be complete, you have produced a sea of documents and diagrams but are no closer to a cogent analysis of the problem than you were on January 3. **** And then, a miracle happens.   **** On Saturday, April 1, you check your e-mail from home. You see a memo from your boss to BB. It states unequivocally that you are done with the analysis! You phone your boss and complain. "How could you have told BB that we were done with the analysis?" "Have you looked at a calendar lately?" he responds. "It's April 1!" The irony of that date does not escape you. "But we have so much more to think about. So much more to analyze! We haven't even decided whether to use <<extends>> or <<precedes>>!" "Where is your evidence that you are not done?" inquires your boss, impatiently. "Whaaa . . . ." But he cuts you off. "Analysis can go on forever; it has to be stopped at some point. And since this is the date it was scheduled to stop, it has been stopped. Now, on Monday, I want you to gather up all existing analysis materials and put them into a public folder. Release that folder to Prudence so that she can log it in the CM system by Monday afternoon. Then get busy and start designing."   As you hang up the phone, you begin to consider the benefits of keeping a bottle of bourbon in your bottom desk drawer. They threw a party to celebrate the on-time completion of the analysis phase. BB gave a colon-stirring speech on empowerment. And your boss, another 3 mm taller, congratulated his team on the incredible show of unity and teamwork. Finally, the CIO takes the stage to tell everyone that the SEI audit went very well and to thank everyone for studying and shredding the evaluation guides that were passed out. Level 3 now seems assured and will be awarded by June. (Scuttlebutt has it that managers at the level of BB and above are to receive significant bonuses once the SEI awards level 3.)   As the weeks flow by, you and your team work on the design of the system. Of course, you find that the analysis that the design is supposedly based on is flawedno, useless; no, worse than useless. But when you tell your boss that you need to go back and work some more on the analysis to shore up its weaker sections, he simply states, "The analysis phase is over. The only allowable activity is design. Now get back to it."   So, you and your team hack the design as best you can, unsure of whether the requirements have been properly analyzed. Of course, it really doesn't matter much, since the requirements document is still thrashing with weekly revisions, and the marketing department still refuses to meet with you.     The design is a nightmare. Your boss recently misread a book named The Finish Line in which the author, Mark DeThomaso, blithely suggested that design documents should be taken down to code-level detail. "If we are going to be working at that level of detail," you ask, "why don't we simply write the code instead?" "Because then you wouldn't be designing, of course. And the only allowable activity in the design phase is design!" "Besides," he continues, "we have just purchased a companywide license for Dandelion! This tool enables 'Round the Horn Engineering!' You are to transfer all design diagrams into this tool. It will automatically generate our code for us! It will also keep the design diagrams in sync with the code!" Your boss hands you a brightly colored shrinkwrapped box containing the Dandelion distribution. You accept it numbly and shuffle off to your cubicle. Twelve hours, eight crashes, one disk reformatting, and eight shots of 151 later, you finally have the tool installed on your server. You consider the week your team will lose while attending Dandelion training. Then you smile and think, "Any week I'm not here is a good week." Design diagram after design diagram is created by your team. Dandelion makes it very difficult to draw these diagrams. There are dozens and dozens of deeply nested dialog boxes with funny text fields and check boxes that must all be filled in correctly. And then there's the problem of moving classes between packages. At first, these diagram are driven from the use cases. But the requirements are changing so often that the use cases rapidly become meaningless. Debates rage about whether VISITOR or DECORATOR design patterns should be used. One developer refuses to use VISITOR in any form, claiming that it's not a properly object-oriented construct. Someone refuses to use multiple inheritance, since it is the spawn of the devil. Review meetings rapidly degenerate into debates about the meaning of object orientation, the definition of analysis versus design, or when to use aggregation versus association. Midway through the design cycle, the marketing folks announce that they have rethought the focus of the system. Their new requirements document is completely restructured. They have eliminated several major feature areas and replaced them with feature areas that they anticipate customer surveys will show to be more appropriate. You tell your boss that these changes mean that you need to reanalyze and redesign much of the system. But he says, "The analysis phase is system. But he says, "The analysis phase is over. The only allowable activity is design. Now get back to it."   You suggest that it might be better to create a simple prototype to show to the marketing folks and even some potential customers. But your boss says, "The analysis phase is over. The only allowable activity is design. Now get back to it." Hack, hack, hack, hack. You try to create some kind of a design document that might reflect the new requirements documents. However, the revolution of the requirements has not caused them to stop thrashing. Indeed, if anything, the wild oscillations of the requirements document have only increased in frequency and amplitude.   You slog your way through them.   On June 15, the Dandelion database gets corrupted. Apparently, the corruption has been progressive. Small errors in the DB accumulated over the months into bigger and bigger errors. Eventually, the CASE tool just stopped working. Of course, the slowly encroaching corruption is present on all the backups. Calls to the Dandelion technical support line go unanswered for several days. Finally, you receive a brief e-mail from Dandelion, informing you that this is a known problem and that the solution is to purchase the new version, which they promise will be ready some time next quarter, and then reenter all the diagrams by hand.   ****   Then, on July 1 another miracle happens! You are done with the design!   Rather than go to your boss and complain, you stock your middle desk drawer with some vodka.   **** They threw a party to celebrate the on-time completion of the design phase and their graduation to CMM level 3. This time, you find BB's speech so stirring that you have to use the restroom before it begins. New banners and plaques are all over your workplace. They show pictures of eagles and mountain climbers, and they talk about teamwork and empowerment. They read better after a few scotches. That reminds you that you need to clear out your file cabinet to make room for the brandy. You and your team begin to code. But you rapidly discover that the design is lacking in some significant areas. Actually, it's lacking any significance at all. You convene a design session in one of the conference rooms to try to work through some of the nastier problems. But your boss catches you at it and disbands the meeting, saying, "The design phase is over. The only allowable activity is coding. Now get back to it."   ****   The code generated by Dandelion is really hideous. It turns out that you and your team were using association and aggregation the wrong way, after all. All the generated code has to be edited to correct these flaws. Editing this code is extremely difficult because it has been instrumented with ugly comment blocks that have special syntax that Dandelion needs in order to keep the diagrams in sync with the code. If you accidentally alter one of these comments, the diagrams will be regenerated incorrectly. It turns out that "Round the Horn Engineering" requires an awful lot of effort. The more you try to keep the code compatible with Dandelion, the more errors Dandelion generates. In the end, you give up and decide to keep the diagrams up to date manually. A second later, you decide that there's no point in keeping the diagrams up to date at all. Besides, who has time?   Your boss hires a consultant to build tools to count the number of lines of code that are being produced. He puts a big thermometer graph on the wall with the number 1,000,000 on the top. Every day, he extends the red line to show how many lines have been added. Three days after the thermometer appears on the wall, your boss stops you in the hall. "That graph isn't growing quickly enough. We need to have a million lines done by October 1." "We aren't even sh-sh-sure that the proshect will require a m-million linezh," you blather. "We have to have a million lines done by October 1," your boss reiterates. His points have grown again, and the Grecian formula he uses on them creates an aura of authority and competence. "Are you sure your comment blocks are big enough?" Then, in a flash of managerial insight, he says, "I have it! I want you to institute a new policy among the engineers. No line of code is to be longer than 20 characters. Any such line must be split into two or more preferably more. All existing code needs to be reworked to this standard. That'll get our line count up!"   You decide not to tell him that this will require two unscheduled work months. You decide not to tell him anything at all. You decide that intravenous injections of pure ethanol are the only solution. You make the appropriate arrangements. Hack, hack, hack, and hack. You and your team madly code away. By August 1, your boss, frowning at the thermometer on the wall, institutes a mandatory 50-hour workweek.   Hack, hack, hack, and hack. By September 1st, the thermometer is at 1.2 million lines and your boss asks you to write a report describing why you exceeded the coding budget by 20 percent. He institutes mandatory Saturdays and demands that the project be brought back down to a million lines. You start a campaign of remerging lines. Hack, hack, hack, and hack. Tempers are flaring; people are quitting; QA is raining trouble reports down on you. Customers are demanding installation and user manuals; salespeople are demanding advance demonstrations for special customers; the requirements document is still thrashing, the marketing folks are complaining that the product isn't anything like they specified, and the liquor store won't accept your credit card anymore. Something has to give.    On September 15, BB calls a meeting. As he enters the room, his points are emitting clouds of steam. When he speaks, the bass overtones of his carefully manicured voice cause the pit of your stomach to roll over. "The QA manager has told me that this project has less than 50 percent of the required features implemented. He has also informed me that the system crashes all the time, yields wrong results, and is hideously slow. He has also complained that he cannot keep up with the continuous train of daily releases, each more buggy than the last!" He stops for a few seconds, visibly trying to compose himself. "The QA manager estimates that, at this rate of development, we won't be able to ship the product until December!" Actually, you think it's more like March, but you don't say anything. "December!" BB roars with such derision that people duck their heads as though he were pointing an assault rifle at them. "December is absolutely out of the question. Team leaders, I want new estimates on my desk in the morning. I am hereby mandating 65-hour work weeks until this project is complete. And it better be complete by November 1."   As he leaves the conference room, he is heard to mutter: "Empowermentbah!" * * * Your boss is bald; his points are mounted on BB's wall. The fluorescent lights reflecting off his pate momentarily dazzle you. "Do you have anything to drink?" he asks. Having just finished your last bottle of Boone's Farm, you pull a bottle of Thunderbird from your bookshelf and pour it into his coffee mug. "What's it going to take to get this project done? " he asks. "We need to freeze the requirements, analyze them, design them, and then implement them," you say callously. "By November 1?" your boss exclaims incredulously. "No way! Just get back to coding the damned thing." He storms out, scratching his vacant head.   A few days later, you find that your boss has been transferred to the corporate research division. Turnover has skyrocketed. Customers, informed at the last minute that their orders cannot be fulfilled on time, have begun to cancel their orders. Marketing is re-evaluating whether this product aligns with the overall goals of the company. Memos fly, heads roll, policies change, and things are, overall, pretty grim. Finally, by March, after far too many sixty-five hour weeks, a very shaky version of the software is ready. In the field, bug-discovery rates are high, and the technical support staff are at their wits' end, trying to cope with the complaints and demands of the irate customers. Nobody is happy.   In April, BB decides to buy his way out of the problem by licensing a product produced by Rupert Industries and redistributing it. The customers are mollified, the marketing folks are smug, and you are laid off.     Rupert Industries: Project Alpha   Your name is Robert. The date is January 3, 2001. The quiet hours spent with your family this holiday have left you refreshed and ready for work. You are sitting in a conference room with your team of professionals. The manager of the division called the meeting. "We have some ideas for a new project," says the division manager. Call him Russ. He is a high-strung British chap with more energy than a fusion reactor. He is ambitious and driven but understands the value of a team. Russ describes the essence of the new market opportunity the company has identified and introduces you to Jane, the marketing manager, who is responsible for defining the products that will address it. Addressing you, Jane says, "We'd like to start defining our first product offering as soon as possible. When can you and your team meet with me?" You reply, "We'll be done with the current iteration of our project this Friday. We can spare a few hours for you between now and then. After that, we'll take a few people from the team and dedicate them to you. We'll begin hiring their replacements and the new people for your team immediately." "Great," says Russ, "but I want you to understand that it is critical that we have something to exhibit at the trade show coming up this July. If we can't be there with something significant, we'll lose the opportunity."   "I understand," you reply. "I don't yet know what it is that you have in mind, but I'm sure we can have something by July. I just can't tell you what that something will be right now. In any case, you and Jane are going to have complete control over what we developers do, so you can rest assured that by July, you'll have the most important things that can be accomplished in that time ready to exhibit."   Russ nods in satisfaction. He knows how this works. Your team has always kept him advised and allowed him to steer their development. He has the utmost confidence that your team will work on the most important things first and will produce a high-quality product.   * * *   "So, Robert," says Jane at their first meeting, "How does your team feel about being split up?" "We'll miss working with each other," you answer, "but some of us were getting pretty tired of that last project and are looking forward to a change. So, what are you people cooking up?" Jane beams. "You know how much trouble our customers currently have . . ." And she spends a half hour or so describing the problem and possible solution. "OK, wait a second" you respond. "I need to be clear about this." And so you and Jane talk about how this system might work. Some of her ideas aren't fully formed. You suggest possible solutions. She likes some of them. You continue discussing.   During the discussion, as each new topic is addressed, Jane writes user story cards. Each card represents something that the new system has to do. The cards accumulate on the table and are spread out in front of you. Both you and Jane point at them, pick them up, and make notes on them as you discuss the stories. The cards are powerful mnemonic devices that you can use to represent complex ideas that are barely formed.   At the end of the meeting, you say, "OK, I've got a general idea of what you want. I'm going to talk to the team about it. I imagine they'll want to run some experiments with various database structures and presentation formats. Next time we meet, it'll be as a group, and we'll start identifying the most important features of the system."   A week later, your nascent team meets with Jane. They spread the existing user story cards out on the table and begin to get into some of the details of the system. The meeting is very dynamic. Jane presents the stories in the order of their importance. There is much discussion about each one. The developers are concerned about keeping the stories small enough to estimate and test. So they continually ask Jane to split one story into several smaller stories. Jane is concerned that each story have a clear business value and priority, so as she splits them, she makes sure that this stays true.   The stories accumulate on the table. Jane writes them, but the developers make notes on them as needed. Nobody tries to capture everything that is said; the cards are not meant to capture everything but are simply reminders of the conversation.   As the developers become more comfortable with the stories, they begin writing estimates on them. These estimates are crude and budgetary, but they give Jane an idea of what the story will cost.   At the end of the meeting, it is clear that many more stories could be discussed. It is also clear that the most important stories have been addressed and that they represent several months worth of work. Jane closes the meeting by taking the cards with her and promising to have a proposal for the first release in the morning.   * * *   The next morning, you reconvene the meeting. Jane chooses five cards and places them on the table. "According to your estimates, these cards represent about one perfect team-week's worth of work. The last iteration of the previous project managed to get one perfect team-week done in 3 real weeks. If we can get these five stories done in 3 weeks, we'll be able to demonstrate them to Russ. That will make him feel very comfortable about our progress." Jane is pushing it. The sheepish look on her face lets you know that she knows it too. You reply, "Jane, this is a new team, working on a new project. It's a bit presumptuous to expect that our velocity will be the same as the previous team's. However, I met with the team yesterday afternoon, and we all agreed that our initial velocity should, in fact, be set to one perfectweek for every 3 real-weeks. So you've lucked out on this one." "Just remember," you continue, "that the story estimates and the story velocity are very tentative at this point. We'll learn more when we plan the iteration and even more when we implement it."   Jane looks over her glasses at you as if to say "Who's the boss around here, anyway?" and then smiles and says, "Yeah, don't worry. I know the drill by now."Jane then puts 15 more cards on the table. She says, "If we can get all these cards done by the end of March, we can turn the system over to our beta test customers. And we'll get good feedback from them."   You reply, "OK, so we've got our first iteration defined, and we have the stories for the next three iterations after that. These four iterations will make our first release."   "So," says Jane, can you really do these five stories in the next 3 weeks?" "I don't know for sure, Jane," you reply. "Let's break them down into tasks and see what we get."   So Jane, you, and your team spend the next several hours taking each of the five stories that Jane chose for the first iteration and breaking them down into small tasks. The developers quickly realize that some of the tasks can be shared between stories and that other tasks have commonalities that can probably be taken advantage of. It is clear that potential designs are popping into the developers' heads. From time to time, they form little discussion knots and scribble UML diagrams on some cards.   Soon, the whiteboard is filled with the tasks that, once completed, will implement the five stories for this iteration. You start the sign-up process by saying, "OK, let's sign up for these tasks." "I'll take the initial database generation." Says Pete. "That's what I did on the last project, and this doesn't look very different. I estimate it at two of my perfect workdays." "OK, well, then, I'll take the login screen," says Joe. "Aw, darn," says Elaine, the junior member of the team, "I've never done a GUI, and kinda wanted to try that one."   "Ah, the impatience of youth," Joe says sagely, with a wink in your direction. "You can assist me with it, young Jedi." To Jane: "I think it'll take me about three of my perfect workdays."   One by one, the developers sign up for tasks and estimate them in terms of their own perfect workdays. Both you and Jane know that it is best to let the developers volunteer for tasks than to assign the tasks to them. You also know full well that you daren't challenge any of the developers' estimates. You know these people, and you trust them. You know that they are going to do the very best they can.   The developers know that they can't sign up for more perfect workdays than they finished in the last iteration they worked on. Once each developer has filled his or her schedule for the iteration, they stop signing up for tasks.   Eventually, all the developers have stopped signing up for tasks. But, of course, tasks are still left on the board.   "I was worried that that might happen," you say, "OK, there's only one thing to do, Jane. We've got too much to do in this iteration. What stories or tasks can we remove?" Jane sighs. She knows that this is the only option. Working overtime at the beginning of a project is insane, and projects where she's tried it have not fared well.   So Jane starts to remove the least-important functionality. "Well, we really don't need the login screen just yet. We can simply start the system in the logged-in state." "Rats!" cries Elaine. "I really wanted to do that." "Patience, grasshopper." says Joe. "Those who wait for the bees to leave the hive will not have lips too swollen to relish the honey." Elaine looks confused. Everyone looks confused. "So . . .," Jane continues, "I think we can also do away with . . ." And so, bit by bit, the list of tasks shrinks. Developers who lose a task sign up for one of the remaining ones.   The negotiation is not painless. Several times, Jane exhibits obvious frustration and impatience. Once, when tensions are especially high, Elaine volunteers, "I'll work extra hard to make up some of the missing time." You are about to correct her when, fortunately, Joe looks her in the eye and says, "When once you proceed down the dark path, forever will it dominate your destiny."   In the end, an iteration acceptable to Jane is reached. It's not what Jane wanted. Indeed, it is significantly less. But it's something the team feels that can be achieved in the next 3 weeks.   And, after all, it still addresses the most important things that Jane wanted in the iteration. "So, Jane," you say when things had quieted down a bit, "when can we expect acceptance tests from you?" Jane sighs. This is the other side of the coin. For every story the development team implements,   Jane must supply a suite of acceptance tests that prove that it works. And the team needs these long before the end of the iteration, since they will certainly point out differences in the way Jane and the developers imagine the system's behaviour.   "I'll get you some example test scripts today," Jane promises. "I'll add to them every day after that. You'll have the entire suite by the middle of the iteration."   * * *   The iteration begins on Monday morning with a flurry of Class, Responsibilities, Collaborators sessions. By midmorning, all the developers have assembled into pairs and are rapidly coding away. "And now, my young apprentice," Joe says to Elaine, "you shall learn the mysteries of test-first design!"   "Wow, that sounds pretty rad," Elaine replies. "How do you do it?" Joe beams. It's clear that he has been anticipating this moment. "OK, what does the code do right now?" "Huh?" replied Elaine, "It doesn't do anything at all; there is no code."   "So, consider our task; can you think of something the code should do?" "Sure," Elaine said with youthful assurance, "First, it should connect to the database." "And thereupon, what must needs be required to connecteth the database?" "You sure talk weird," laughed Elaine. "I think we'd have to get the database object from some registry and call the Connect() method. "Ah, astute young wizard. Thou perceives correctly that we requireth an object within which we can cacheth the database object." "Is 'cacheth' really a word?" "It is when I say it! So, what test can we write that we know the database registry should pass?" Elaine sighs. She knows she'll just have to play along. "We should be able to create a database object and pass it to the registry in a Store() method. And then we should be able to pull it out of the registry with a Get() method and make sure it's the same object." "Oh, well said, my prepubescent sprite!" "Hay!" "So, now, let's write a test function that proves your case." "But shouldn't we write the database object and registry object first?" "Ah, you've much to learn, my young impatient one. Just write the test first." "But it won't even compile!" "Are you sure? What if it did?" "Uh . . ." "Just write the test, Elaine. Trust me." And so Joe, Elaine, and all the other developers began to code their tasks, one test case at a time. The room in which they worked was abuzz with the conversations between the pairs. The murmur was punctuated by an occasional high five when a pair managed to finish a task or a difficult test case.   As development proceeded, the developers changed partners once or twice a day. Each developer got to see what all the others were doing, and so knowledge of the code spread generally throughout the team.   Whenever a pair finished something significant whether a whole task or simply an important part of a task they integrated what they had with the rest of the system. Thus, the code base grew daily, and integration difficulties were minimized.   The developers communicated with Jane on a daily basis. They'd go to her whenever they had a question about the functionality of the system or the interpretation of an acceptance test case.   Jane, good as her word, supplied the team with a steady stream of acceptance test scripts. The team read these carefully and thereby gained a much better understanding of what Jane expected the system to do. By the beginning of the second week, there was enough functionality to demonstrate to Jane. She watched eagerly as the demonstration passed test case after test case. "This is really cool," Jane said as the demonstration finally ended. "But this doesn't seem like one-third of the tasks. Is your velocity slower than anticipated?"   You grimace. You'd been waiting for a good time to mention this to Jane but now she was forcing the issue. "Yes, unfortunately, we are going more slowly than we had expected. The new application server we are using is turning out to be a pain to configure. Also, it takes forever to reboot, and we have to reboot it whenever we make even the slightest change to its configuration."   Jane eyes you with suspicion. The stress of last Monday's negotiations had still not entirely dissipated. She says, "And what does this mean to our schedule? We can't slip it again, we just can't. Russ will have a fit! He'll haul us all into the woodshed and ream us some new ones."   You look Jane right in the eyes. There's no pleasant way to give someone news like this. So you just blurt out, "Look, if things keep going like they're going, we're not going to be done with everything by next Friday. Now it's possible that we'll figure out a way to go faster. But, frankly, I wouldn't depend on that. You should start thinking about one or two tasks that could be removed from the iteration without ruining the demonstration for Russ. Come hell or high water, we are going to give that demonstration on Friday, and I don't think you want us to choose which tasks to omit."   "Aw forchrisakes!" Jane barely manages to stifle yelling that last word as she stalks away, shaking her head. Not for the first time, you say to yourself, "Nobody ever promised me project management would be easy." You are pretty sure it won't be the last time, either.   Actually, things went a bit better than you had hoped. The team did, in fact, have to drop one task from the iteration, but Jane had chosen wisely, and the demonstration for Russ went without a hitch. Russ was not impressed with the progress, but neither was he dismayed. He simply said, "This is pretty good. But remember, we have to be able to demonstrate this system at the trade show in July, and at this rate, it doesn't look like you'll have all that much to show." Jane, whose attitude had improved dramatically with the completion of the iteration, responded to Russ by saying, "Russ, this team is working hard, and well. When July comes around, I am confident that we'll have something significant to demonstrate. It won't be everything, and some of it may be smoke and mirrors, but we'll have something."   Painful though the last iteration was, it had calibrated your velocity numbers. The next iteration went much better. Not because your team got more done than in the last iteration but simply because the team didn't have to remove any tasks or stories in the middle of the iteration.   By the start of the fourth iteration, a natural rhythm has been established. Jane, you, and the team know exactly what to expect from one another. The team is running hard, but the pace is sustainable. You are confident that the team can keep up this pace for a year or more.   The number of surprises in the schedule diminishes to near zero; however, the number of surprises in the requirements does not. Jane and Russ frequently look over the growing system and make recommendations or changes to the existing functionality. But all parties realize that these changes take time and must be scheduled. So the changes do not cause anyone's expectations to be violated. In March, there is a major demonstration of the system to the board of directors. The system is very limited and is not yet in a form good enough to take to the trade show, but progress is steady, and the board is reasonably impressed.   The second release goes even more smoothly than the first. By now, the team has figured out a way to automate Jane's acceptance test scripts. The team has also refactored the design of the system to the point that it is really easy to add new features and change old ones. The second release was done by the end of June and was taken to the trade show. It had less in it than Jane and Russ would have liked, but it did demonstrate the most important features of the system. Although customers at the trade show noticed that certain features were missing, they were very impressed overall. You, Russ, and Jane all returned from the trade show with smiles on your faces. You all felt as though this project was a winner.   Indeed, many months later, you are contacted by Rufus Inc. That company had been working on a system like this for its internal operations. Rufus has canceled the development of that system after a death-march project and is negotiating to license your technology for its environment.   Indeed, things are looking up!

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  • Parallelism in .NET – Part 9, Configuration in PLINQ and TPL

    - by Reed
    Parallel LINQ and the Task Parallel Library contain many options for configuration.  Although the default configuration options are often ideal, there are times when customizing the behavior is desirable.  Both frameworks provide full configuration support. When working with Data Parallelism, there is one primary configuration option we often need to control – the number of threads we want the system to use when parallelizing our routine.  By default, PLINQ and the TPL both use the ThreadPool to schedule tasks.  Given the major improvements in the ThreadPool in CLR 4, this default behavior is often ideal.  However, there are times that the default behavior is not appropriate.  For example, if you are working on multiple threads simultaneously, and want to schedule parallel operations from within both threads, you might want to consider restricting each parallel operation to using a subset of the processing cores of the system.  Not doing this might over-parallelize your routine, which leads to inefficiencies from having too many context switches. In the Task Parallel Library, configuration is handled via the ParallelOptions class.  All of the methods of the Parallel class have an overload which accepts a ParallelOptions argument. We configure the Parallel class by setting the ParallelOptions.MaxDegreeOfParallelism property.  For example, let’s revisit one of the simple data parallel examples from Part 2: Parallel.For(0, pixelData.GetUpperBound(0), row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, we’re looping through an image, and calling a method on each pixel in the image.  If this was being done on a separate thread, and we knew another thread within our system was going to be doing a similar operation, we likely would want to restrict this to using half of the cores on the system.  This could be accomplished easily by doing: var options = new ParallelOptions(); options.MaxDegreeOfParallelism = Math.Max(Environment.ProcessorCount / 2, 1); Parallel.For(0, pixelData.GetUpperBound(0), options, row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); Now, we’re restricting this routine to using no more than half the cores in our system.  Note that I included a check to prevent a single core system from supplying zero; without this check, we’d potentially cause an exception.  I also did not hard code a specific value for the MaxDegreeOfParallelism property.  One of our goals when parallelizing a routine is allowing it to scale on better hardware.  Specifying a hard-coded value would contradict that goal. Parallel LINQ also supports configuration, and in fact, has quite a few more options for configuring the system.  The main configuration option we most often need is the same as our TPL option: we need to supply the maximum number of processing threads.  In PLINQ, this is done via a new extension method on ParallelQuery<T>: ParallelEnumerable.WithDegreeOfParallelism. Let’s revisit our declarative data parallelism sample from Part 6: double min = collection.AsParallel().Min(item => item.PerformComputation()); Here, we’re performing a computation on each element in the collection, and saving the minimum value of this operation.  If we wanted to restrict this to a limited number of threads, we would add our new extension method: int maxThreads = Math.Max(Environment.ProcessorCount / 2, 1); double min = collection .AsParallel() .WithDegreeOfParallelism(maxThreads) .Min(item => item.PerformComputation()); This automatically restricts the PLINQ query to half of the threads on the system. PLINQ provides some additional configuration options.  By default, PLINQ will occasionally revert to processing a query in parallel.  This occurs because many queries, if parallelized, typically actually cause an overall slowdown compared to a serial processing equivalent.  By analyzing the “shape” of the query, PLINQ often decides to run a query serially instead of in parallel.  This can occur for (taken from MSDN): Queries that contain a Select, indexed Where, indexed SelectMany, or ElementAt clause after an ordering or filtering operator that has removed or rearranged original indices. Queries that contain a Take, TakeWhile, Skip, SkipWhile operator and where indices in the source sequence are not in the original order. Queries that contain Zip or SequenceEquals, unless one of the data sources has an originally ordered index and the other data source is indexable (i.e. an array or IList(T)). Queries that contain Concat, unless it is applied to indexable data sources. Queries that contain Reverse, unless applied to an indexable data source. If the specific query follows these rules, PLINQ will run the query on a single thread.  However, none of these rules look at the specific work being done in the delegates, only at the “shape” of the query.  There are cases where running in parallel may still be beneficial, even if the shape is one where it typically parallelizes poorly.  In these cases, you can override the default behavior by using the WithExecutionMode extension method.  This would be done like so: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .Select(i => i.PerformComputation()) .Reverse(); Here, the default behavior would be to not parallelize the query unless collection implemented IList<T>.  We can force this to run in parallel by adding the WithExecutionMode extension method in the method chain. Finally, PLINQ has the ability to configure how results are returned.  When a query is filtering or selecting an input collection, the results will need to be streamed back into a single IEnumerable<T> result.  For example, the method above returns a new, reversed collection.  In this case, the processing of the collection will be done in parallel, but the results need to be streamed back to the caller serially, so they can be enumerated on a single thread. This streaming introduces overhead.  IEnumerable<T> isn’t designed with thread safety in mind, so the system needs to handle merging the parallel processes back into a single stream, which introduces synchronization issues.  There are two extremes of how this could be accomplished, but both extremes have disadvantages. The system could watch each thread, and whenever a thread produces a result, take that result and send it back to the caller.  This would mean that the calling thread would have access to the data as soon as data is available, which is the benefit of this approach.  However, it also means that every item is introducing synchronization overhead, since each item needs to be merged individually. On the other extreme, the system could wait until all of the results from all of the threads were ready, then push all of the results back to the calling thread in one shot.  The advantage here is that the least amount of synchronization is added to the system, which means the query will, on a whole, run the fastest.  However, the calling thread will have to wait for all elements to be processed, so this could introduce a long delay between when a parallel query begins and when results are returned. The default behavior in PLINQ is actually between these two extremes.  By default, PLINQ maintains an internal buffer, and chooses an optimal buffer size to maintain.  Query results are accumulated into the buffer, then returned in the IEnumerable<T> result in chunks.  This provides reasonably fast access to the results, as well as good overall throughput, in most scenarios. However, if we know the nature of our algorithm, we may decide we would prefer one of the other extremes.  This can be done by using the WithMergeOptions extension method.  For example, if we know that our PerformComputation() routine is very slow, but also variable in runtime, we may want to retrieve results as they are available, with no bufferring.  This can be done by changing our above routine to: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .WithMergeOptions(ParallelMergeOptions.NotBuffered) .Select(i => i.PerformComputation()) .Reverse(); On the other hand, if are already on a background thread, and we want to allow the system to maximize its speed, we might want to allow the system to fully buffer the results: var reversed = collection .AsParallel() .WithExecutionMode(ParallelExecutionMode.ForceParallelism) .WithMergeOptions(ParallelMergeOptions.FullyBuffered) .Select(i => i.PerformComputation()) .Reverse(); Notice, also, that you can specify multiple configuration options in a parallel query.  By chaining these extension methods together, we generate a query that will always run in parallel, and will always complete before making the results available in our IEnumerable<T>.

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  • sudo apt-get update problem

    - by Jeon
    I have a problem with sudo apt-get update that I can't seem to fix and It's causing problems with alot of installations I want to do. I run Ubuntu 12.04. Ign http://ftp.availo.se precise InRelease Ign http://ftp.availo.se precise-updates InRelease Ign http://ftp.availo.se precise-backports InRelease Ign http://ftp.availo.se precise-security InRelease Get:1 http://repository.spotify.com stable InRelease [2,979 B] Ign http://ppa.launchpad.net precise InRelease Ign http://extras.ubuntu.com precise InRelease Ign http://archive.canonical.com precise InRelease Ign http://ppa.launchpad.net precise InRelease Ign http://ppa.launchpad.net precise InRelease Ign http://repository.spotify.com stable InRelease Ign http://ftp.availo.se precise Release.gpg Ign http://ftp.availo.se precise-updates Release.gpg Ign http://ftp.availo.se precise-backports Release.gpg Ign http://repository.spotify.com stable/non-free amd64 Packages/DiffIndex Hit http://ppa.launchpad.net precise Release.gpg Hit http://ppa.launchpad.net precise Release.gpg Hit http://archive.canonical.com precise Release.gpg Hit http://extras.ubuntu.com precise Release.gpg Ign http://ftp.availo.se precise-security Release.gpg Ign http://repository.spotify.com stable/non-free i386 Packages/DiffIndex Ign http://repository.spotify.com stable/non-free TranslationIndex Hit http://ppa.launchpad.net precise Release.gpg Hit http://archive.canonical.com precise Release Hit http://extras.ubuntu.com precise Release Ign http://ftp.availo.se precise Release Ign http://ftp.availo.se precise-updates Release Hit http://ppa.launchpad.net precise Release Hit http://archive.canonical.com precise/partner amd64 Packages Hit http://extras.ubuntu.com precise/main Sources Ign http://ftp.availo.se precise-backports Release Ign http://ftp.availo.se precise-security Release Hit http://ppa.launchpad.net precise Release Hit http://archive.canonical.com precise/partner i386 Packages Ign http://archive.canonical.com precise/partner TranslationIndex Hit http://ppa.launchpad.net precise Release Hit http://extras.ubuntu.com precise/main amd64 Packages Hit http://extras.ubuntu.com precise/main i386 Packages Ign http://ftp.availo.se precise/main TranslationIndex Ign http://ftp.availo.se precise/multiverse TranslationIndex Ign http://ftp.availo.se precise/restricted TranslationIndex Hit http://ppa.launchpad.net precise/main Sources Hit http://ppa.launchpad.net precise/main amd64 Packages Hit http://ppa.launchpad.net precise/main i386 Packages Ign http://ppa.launchpad.net precise/main TranslationIndex Ign http://extras.ubuntu.com precise/main TranslationIndex Ign http://ftp.availo.se precise/universe TranslationIndex Hit http://ppa.launchpad.net precise/main Sources Hit http://ppa.launchpad.net precise/main amd64 Packages Hit http://ppa.launchpad.net precise/main i386 Packages Ign http://ppa.launchpad.net precise/main TranslationIndex Hit http://ppa.launchpad.net precise/main Sources Hit http://ppa.launchpad.net precise/main amd64 Packages Hit http://ppa.launchpad.net precise/main i386 Packages Ign http://ppa.launchpad.net precise/main TranslationIndex Ign http://ftp.availo.se precise-updates/main TranslationIndex Ign http://ftp.availo.se precise-updates/multiverse TranslationIndex Ign http://ftp.availo.se precise-updates/restricted TranslationIndex Ign http://ftp.availo.se precise-updates/universe TranslationIndex Hit http://repository.spotify.com stable/non-free amd64 Packages Ign http://ftp.availo.se precise-backports/main TranslationIndex Ign http://ftp.availo.se precise-backports/multiverse TranslationIndex Ign http://ftp.availo.se precise-backports/restricted TranslationIndex Ign http://ftp.availo.se precise-backports/universe TranslationIndex Hit http://repository.spotify.com stable/non-free i386 Packages Ign http://archive.canonical.com precise/partner Translation-en_US Ign http://ftp.availo.se precise-security/main TranslationIndex Ign http://ftp.availo.se precise-security/multiverse TranslationIndex Ign http://ftp.availo.se precise-security/restricted TranslationIndex Ign http://ftp.availo.se precise-security/universe TranslationIndex Ign http://repository.spotify.com stable/non-free Translation-en_US Ign http://archive.canonical.com precise/partner Translation-en Ign http://repository.spotify.com stable/non-free Translation-en Ign http://extras.ubuntu.com precise/main Translation-en_US Ign http://extras.ubuntu.com precise/main Translation-en Ign http://ppa.launchpad.net precise/main Translation-en_US Ign http://ppa.launchpad.net precise/main Translation-en Ign http://ppa.launchpad.net precise/main Translation-en_US Ign http://ppa.launchpad.net precise/main Translation-en Ign http://ppa.launchpad.net precise/main Translation-en_US Ign http://ppa.launchpad.net precise/main Translation-en Err http://ftp.availo.se precise/main Sources 404 Not Found Err http://ftp.availo.se precise/restricted Sources 404 Not Found Err http://ftp.availo.se precise/universe Sources 404 Not Found Err http://ftp.availo.se precise/multiverse Sources 404 Not Found Err http://ftp.availo.se precise/main amd64 Packages 404 Not Found Err http://ftp.availo.se precise/restricted amd64 Packages 404 Not Found Err http://ftp.availo.se precise/universe amd64 Packages 404 Not Found Err http://ftp.availo.se precise/multiverse amd64 Packages 404 Not Found Err http://ftp.availo.se precise/main i386 Packages 404 Not Found Err http://ftp.availo.se precise/restricted i386 Packages 404 Not Found Err http://ftp.availo.se precise/universe i386 Packages 404 Not Found Err http://ftp.availo.se precise/multiverse i386 Packages 404 Not Found Err http://ftp.availo.se precise-updates/main Sources 404 Not Found Err http://ftp.availo.se precise-updates/restricted Sources 404 Not Found Err http://ftp.availo.se precise-updates/universe Sources 404 Not Found Err http://ftp.availo.se precise-updates/multiverse Sources 404 Not Found Err http://ftp.availo.se precise-updates/main amd64 Packages 404 Not Found Err http://ftp.availo.se precise-updates/restricted amd64 Packages 404 Not Found Err http://ftp.availo.se precise-updates/universe amd64 Packages 404 Not Found Err http://ftp.availo.se precise-updates/multiverse amd64 Packages 404 Not Found Err http://ftp.availo.se precise-updates/main i386 Packages 404 Not Found Err http://ftp.availo.se precise-updates/restricted i386 Packages 404 Not Found Err http://ftp.availo.se precise-updates/universe i386 Packages 404 Not Found Err http://ftp.availo.se precise-updates/multiverse i386 Packages 404 Not Found Err http://ftp.availo.se precise-backports/main Sources 404 Not Found Err http://ftp.availo.se precise-backports/restricted Sources 404 Not Found Err http://ftp.availo.se precise-backports/universe Sources 404 Not Found Err http://ftp.availo.se precise-backports/multiverse Sources 404 Not Found Err http://ftp.availo.se precise-backports/main amd64 Packages 404 Not Found Err http://ftp.availo.se precise-backports/restricted amd64 Packages 404 Not Found Err http://ftp.availo.se precise-backports/universe amd64 Packages 404 Not Found Err http://ftp.availo.se precise-backports/multiverse amd64 Packages 404 Not Found Err http://ftp.availo.se precise-backports/main i386 Packages 404 Not Found Err http://ftp.availo.se precise-backports/restricted i386 Packages 404 Not Found Err http://ftp.availo.se precise-backports/universe i386 Packages 404 Not Found Err http://ftp.availo.se precise-backports/multiverse i386 Packages 404 Not Found Err http://ftp.availo.se precise-security/main Sources 404 Not Found Err http://ftp.availo.se precise-security/restricted Sources 404 Not Found Err http://ftp.availo.se precise-security/universe Sources 404 Not Found Err http://ftp.availo.se precise-security/multiverse Sources 404 Not Found Err http://ftp.availo.se precise-security/main amd64 Packages 404 Not Found Err http://ftp.availo.se precise-security/restricted amd64 Packages 404 Not Found Err http://ftp.availo.se precise-security/universe amd64 Packages 404 Not Found Err http://ftp.availo.se precise-security/multiverse amd64 Packages 404 Not Found Err http://ftp.availo.se precise-security/main i386 Packages 404 Not Found Err http://ftp.availo.se precise-security/restricted i386 Packages 404 Not Found Err http://ftp.availo.se precise-security/universe i386 Packages 404 Not Found Err http://ftp.availo.se precise-security/multiverse i386 Packages 404 Not Found Ign http://ftp.availo.se precise/main Translation-en_US Ign http://ftp.availo.se precise/main Translation-en Ign http://ftp.availo.se precise/multiverse Translation-en_US Ign http://ftp.availo.se precise/multiverse Translation-en Ign http://ftp.availo.se precise/restricted Translation-en_US Ign http://ftp.availo.se precise/restricted Translation-en Ign http://ftp.availo.se precise/universe Translation-en_US Ign http://ftp.availo.se precise/universe Translation-en Ign http://ftp.availo.se precise-updates/main Translation-en_US Ign http://ftp.availo.se precise-updates/main Translation-en Ign http://ftp.availo.se precise-updates/multiverse Translation-en_US Ign http://ftp.availo.se precise-updates/multiverse Translation-en Ign http://ftp.availo.se precise-updates/restricted Translation-en_US Ign http://ftp.availo.se precise-updates/restricted Translation-en Ign http://ftp.availo.se precise-updates/universe Translation-en_US Ign http://ftp.availo.se precise-updates/universe Translation-en Ign http://ftp.availo.se precise-backports/main Translation-en_US Ign http://ftp.availo.se precise-backports/main Translation-en Ign http://ftp.availo.se precise-backports/multiverse Translation-en_US Ign http://ftp.availo.se precise-backports/multiverse Translation-en Ign http://ftp.availo.se precise-backports/restricted Translation-en_US Ign http://ftp.availo.se precise-backports/restricted Translation-en Ign http://ftp.availo.se precise-backports/universe Translation-en_US Ign http://ftp.availo.se precise-backports/universe Translation-en Ign http://ftp.availo.se precise-security/main Translation-en_US Ign http://ftp.availo.se precise-security/main Translation-en Ign http://ftp.availo.se precise-security/multiverse Translation-en_US Ign http://ftp.availo.se precise-security/multiverse Translation-en Ign http://ftp.availo.se precise-security/restricted Translation-en_US Ign http://ftp.availo.se precise-security/restricted Translation-en Ign http://ftp.availo.se precise-security/universe Translation-en_US Ign http://ftp.availo.se precise-security/universe Translation-en Fetched 2,979 B in 9s (328 B/s) W: GPG error: http://repository.spotify.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 082CCEDF94558F59 W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/main/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/restricted/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/universe/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/multiverse/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/main/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/restricted/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/universe/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/multiverse/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/main/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/restricted/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/universe/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise/multiverse/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/main/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/restricted/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/universe/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/multiverse/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/main/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/restricted/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/universe/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/multiverse/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/main/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/restricted/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/universe/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-updates/multiverse/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/main/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/restricted/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/universe/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/multiverse/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/main/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/restricted/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/universe/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/multiverse/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/main/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/restricted/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/universe/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-backports/multiverse/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/main/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/restricted/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/universe/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/multiverse/source/Sources 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/main/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/restricted/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/universe/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/multiverse/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/main/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/restricted/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/universe/binary-i386/Packages 404 Not Found W: Failed to fetch http://ftp.availo.se/ubuntu/dists/precise-security/multiverse/binary-i386/Packages 404 Not Found E: Some index files failed to download. They have been ignored, or old ones used instead. I would appreciate a fix to this. Thank you for the help.

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