Search Results

Search found 23783 results on 952 pages for 'edit and continue'.

Page 538/952 | < Previous Page | 534 535 536 537 538 539 540 541 542 543 544 545  | Next Page >

  • What happens when we say "listen to a port" ?

    - by smwikipedia
    Hi, When we start a server application, we always need to speicify the port number it listens to. But how is this "listening mechanism" implemented under the hood? My current imagination is like this: The operating system associate the port number with some buffer. The server application's responsibiligy is to monitor this buffer. If there's no data in this buffer, the server application's listen operation will just block the application. When some data arrives from the wire, the operating system will know that check the data and see if it is targed at this port number. And then it will fill the buffer. And then OS will notify the blocked server application and the server application will get the data and continue to run. Question is: If the above scenario is correct, how could the opearting system know there's data arriving from wire? It cannot be a busy pooling. Is it some kind of interrupt-based mechanism? If there's too much data arriving and the buffer is not big enough, will there be data loss? Is the "listen to a port" operation really a blocking operation? Many thanks.

    Read the article

  • How do I convert a simple ruby flashcard program into a ROR app?

    - by Mark Wilbur
    What I'm trying to do is make a basic flashcard app on rails. At this point, all I'm looking for is the functionality to iterate through a list of flashcards, quiz the user and let the user know if they were right or not. In ruby, it didn't take me long to write: class Card attr_accessor :answer, :question def initialize(answer = "", question="") @answer = answer @question = question end def quiz puts "What does #@question mean?" answer = gets.chomp if answer == @answer puts "Right" return true else puts "Wrong" return answer end end end class Cardlist attr_accessor :Cards def initialize(Cards = []) @Cards = Cards end def quiz Cards.each do |w| w.quiz end end end The problem I'm having with rails is figuring out where to put the logic to loop through all the cards in the list. I've made models specifying that Card belongs_to cardlist and that Cardlist has_many cards. I know application logic should go in the controller, but if I were to make a "quiz" action for my Cardlist controller, how would I make it iterate through all the cards? After each "quiz" page generated, I'd need to get an answer back from the user, respond (maybe flash) whether it was right or not and then continue onto the next question. Would any of that logic have to go into the view in order to make sure it's sending back the user inputted answers to the controller?

    Read the article

  • Invoking different methods on threads

    - by Kraken
    I have a main process main. It creates 10 threads (say) and then what i want to do is the following: while(required){ Thread t= new Thread(new ClassImplementingRunnable()); t.start(); counter++; } Now i have the list of these threads, and for each thread i want to do a set of process, same for all, hence i put that implementation in the run method of ClassImplementingRunnable. Now after the threads have done their execution, i wan to wait for all of them to stop, and then evoke them again, but this time i want to do them serially not in parallel. for this I join each thread, to wait for them to finish execution but after that i am not sure how to evoke them again and run that piece of code serially. Can i do something like for(each thread){ t.reevoke(); //how can i do that. t.doThis(); // Also where does `dothis()` go, given that my ClassImplementingRunnable is an inner class. } Also, i want to use the same thread, i.e. i want the to continue from where they left off, but in a serial manner. I am not sure how to go about the last piece of pseudo code. Kindly help. Working with with java.

    Read the article

  • PHP's fopen is terminally failing

    - by Skittles
    Okay, I have GOT to be missing something totally rudimentary here. I have an extremely simple use of PHP's fopen function, but for some reason, it will not open the file no matter what I do. The odd part about this is that I use fopen in another function in the same script and it's working perfectly. I'm using the fclose in both functions. So, I know it's not a matter of a rogue file handle. I have confirmed the file's path and the existence of the target file also. I'm running the script at the command-line as root, so I know it's not apache that's the cause. And since I am running the script as root, I am fairly confident that permissions are not the issue. So, what on earth am I missing here? function get_file_list() { $file = '/home/site/tmp/return_files_list.txt'; $fp = fopen($file, 'r') or die("Could not open file: /home/site/tmp/return_files_list.txt for reading.\n"); $files_list = array(); while($line = fgets($fp)) { $files_list[] = $line; } fclose($fp); return $files_list; } function num_records_in_file($filename) { $fp = fopen( $filename, 'r' ); # or die("Could not open file: $filename\n"); $counter = 0; if ($fp) { while (!feof( $fp )) { $line = fgets( $fp ); $arr = explode( '|', $line ); if (( ( $arr[0] != 'HDR' && $arr[0] != 'TRL' ) && $arr[0] != '' )) { ++$counter; continue; } } } fclose( $fp ); return $counter; } As requested, here's both functions. The second function is passed an absolute path to the file. That is what I used to confirm that the file is there and that the path is correct.

    Read the article

  • Pass existing model into AJAX PartialViewResult

    - by Joe
    I’m using AJAX to asynchronously update a partial view and need to pass the existing model into the partial view. Controller Action public ActionResult Edit(int id) { var vM = new MyViewModel(); // vM is viewModel return View(vM); } Edit View @using (Html.BeginForm()) { @Html.ValidationSummary(true) ... <span id = "Ship"> @Html.Partial("AJAX_Views/_Ship")</span> _Ship Partial View @model MyProject.ViewModels.MyViewModel <table class="detailtable" style="min-width:398px"> <tr> <th style="padding-left:132px" colspan="2"> <span class="editor-label">Shipping&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Address</span> <span class="editor-label" style="padding-left:55px"> @Ajax.ActionLink("Delete", "SHIPDEL", new AjaxOptions { UpdateTargetId = "Ship", InsertionMode = InsertionMode.Replace, HttpMethod = "Get" })</span> <tr><th style="min-width:152px"><span class="editor-label">Street:</span></th> @Html.HiddenFor(m => m.CmpAdrsSh.Id) @Html.HiddenFor(m => m.CmpAdrsSh.CompPersonId) @Html.HiddenFor(m => m.CmpAdrsSh.IsShip) <td><span class="editor-field">@Html.EditorFor(m => m.CmpAdrsSh.Street) @Html.ValidationMessageFor(m => m.CmpAdrsSh.Street) </span></td></tr> <tr><th><span class="editor-label">City:</span></th> <td><span class="editor-field">@Html.EditorFor(m => m.CmpAdrsSh.City) @Html.ValidationMessageFor(m => m.CmpAdrsSh.City) </span></td></tr> <tr><th><span class="editor-label">State:</span></th> <td><span class="editor-field">@Html.DropDownList("CmpAdrsSh.State", (IEnumerable<SelectListItem>)ViewBag._State) @Html.ValidationMessageFor(m => m.CmpAdrsSh.State) </span></td></tr> <tr><th><span class="editor-label">Zip:</span></th> <td><span class="editor-field">@Html.EditorFor(m => m.CmpAdrsSh.Zip) @Html.ValidationMessageFor(m => m.CmpAdrsSh.Zip) </span></td></tr> _ShipDel Partial View @model MyProject.ViewModels.MyViewModel <table class="detailtable" style="min-width:398px"> <tr> <th style="padding-left:132px" colspan="2"> <span class="editor-label">Shipping&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Address</span> <span class="editor-label" style="padding-left:10px; color:red">Marked for Deletion.</span></th></tr> <tr><td>To not Delete Select Cancel below!</td></tr> @Html.HiddenFor(m => m.CmpAdrsSh.Street) @Html.HiddenFor(m => m.CmpAdrsSh.City) @Html.HiddenFor(m => m.CmpAdrsSh.State) @Html.HiddenFor(m => m.CmpAdrsSh.Zip) Controller PartialViewResult Action public PartialViewResult SHIPDEL() { return PartialView("AJAX_Views/_ShipDel"); } I tried adding this.ModelState to the Action but then the view will not render. I'm guessing I somehow have to pass the model to the SHIPDEL Action first. I couldn't find an @Ajax.ActionLink overload that would allow this. public PartialViewResult SHIPDEL() { return PartialView("AJAX_Views/_ShipDel", this.ModelState); } In the _ShipDel Partial View I need to expose the CmpAdrsSh properties so the model validates in the POST Action. The model is empty at this point. How do I pass the existing vM model into the _ShipDel partial view? Thank you,

    Read the article

  • Writing out sheet to text file using POI event model

    - by Eduardo Dennis
    I am using XLSX2CSV example to parse large sheets from a workbook. Since I only need to output the data for specific sheets I added an if statement in the process method to test for the specific sheets. When the condition is met I continue with the process. public void process() throws IOException, OpenXML4JException, ParserConfigurationException, SAXException { ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(this.xlsxPackage); XSSFReader xssfReader = new XSSFReader(this.xlsxPackage); StylesTable styles = xssfReader.getStylesTable(); XSSFReader.SheetIterator iter = (XSSFReader.SheetIterator) xssfReader.getSheetsData(); while (iter.hasNext()) { InputStream stream = iter.next(); String sheetName = iter.getSheetName(); if (sheetName.equals("SHEET1")||sheetName.equals("SHEET2")||sheetName.equals("SHEET3")||sheetName.equals("SHEET4")||sheetName.equals("SHEET5")){ processSheet(styles, strings, stream); try { System.setOut(new PrintStream( new FileOutputStream("C:\\Users\\edennis.AD\\Desktop\\test\\"+sheetName+".txt"))); } catch (Exception e) { e.printStackTrace(); } stream.close(); } } } But I need to output text file and not sure how to do it. I tried to use the System.set() method to output everything from system.out to text but that's not working I just get blank files.

    Read the article

  • Where can I find my iPhone app's Core Data persistent store?

    - by Dr Dork
    I'm diving into iPhone development, so I apologize in advance if this is a ridiculous question, but in a new iPad app project using the Core Data framework, here's the generated code for creating the persistentStoreCoordinator... - (NSPersistentStoreCoordinator *)persistentStoreCoordinator { if (persistentStoreCoordinator != nil) { return persistentStoreCoordinator; } NSURL *storeUrl = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"ApplicationName.sqlite"]]; NSError *error = nil; persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]]; if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error]) { /* Replace this implementation with code to handle the error appropriately. abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button. Typical reasons for an error here include: * The persistent store is not accessible * The schema for the persistent store is incompatible with current managed object model Check the error message to determine what the actual problem was. */ NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } return persistentStoreCoordinator; } My questions are... The first time I run the app, is the ApplicationName.sqllite database created automatically if it doesn't exist? If not, when is it created? When data is added to it programmatically? Once the DB does exist, where can I locate the file? I'd like to open it with a different program so I can manually manipulate the data. Thanks so much in advance for your help! I'm going to continue researching these questions right now.

    Read the article

  • What's the correct place to share application logic in CakePHP?

    - by Pichan
    I guess simple answer to the question would be a component. Although I agree, I feel weird having to write a component for something so specific. For example, let's say I have a table of users. When a user is created, it should form a chain reaction of events, initiating different kinds of data related to the user all around the database. I figured it would be best to avoid directly manipulating the database from different controllers and instead pack all that neatly in a method. However since some logic needs to be accesed separately, I really can't have the whole package in a single method. Instead I thought it would be logical to break it up to smaller pieces(like $userModelOrController->createNew() and $candyStorageModelOrController->createNew()) that only interact with their respective database table. Now, if the logic is put to the model, it works great until I need to use other models. Of course it's possible, but when compared to loading models in a controller, it's not that simple. It's like a Cake developer telling me "Sure, it's possible if you want to do it that way but that's not how I would do it". Then, if the logic is put to the controller, I can access other models really easy through $this->loadModel(), but that brings me back to the previously explained situation since I need to be able to continue the chain reaction indefinitely. Accessing other controllers from a controller is possible, but again there doesn't seem to be any direct way of doing so, so I'm guessing I'm still not doing it right. By using a component this problem could be solved easily, since components are available to every controller I want. But like I wrote at the beginning, it feels awkward to create a component specifically for this one task. To me, components seem more like packages of extra functionality(like the core components) and not something to share controller-specific logic. Since I'm new to this whole MVC thing, I could've completely misunderstood the concept. Once again, I would be thankful if someone pointed me to the right direction :)

    Read the article

  • Android newbie installing Eclipse, having issues....

    - by Jeff
    I am a web developer, new to app development and Java/Android. I am about to follow some tutorials to get started learning but I'm running into a wall. The Android dev site says the recommended way to build Android apps is in Java using the Eclipse plug in. So I downloaded Eclipse Classic and unzipped it on to get this error: "A Java Runtime Environment (JRE) or Java Development Kit (JDK) must be available in order to run Eclipse. No Java virtual machine was found after searching the following locations: /Users//Desktop/eclipse/Eclipse.app/Contents/MacOS/jre/bin/java java in your current PATH" Any idea what the issue is and how I can fix it? Again, newbie to java, jre, android, so I apologize if this question has already been asked. In my research I've discovered that most of the posts or solutions I've found are tough for me to follow. There's always a few unclear items that are probably prohibiting me from getting the answer I need. So I'm hoping someone can walk me through installing or configuring whatever I need to regarding Java so I can continue installing Eclipse and begin learning. I should probably note that I'm on Mac OSX 10.6.6 Snow Leopard. Please let me know if you need any other info. Thanks so much in advance for any and all help!!!

    Read the article

  • How to resolve strange conflict between form post and ajax post?

    - by Oliver Hyde
    On the one page, I am trying to use ajax to edit existing values. I am doing this by using jQuery Inline Edit and posting away the new data, updating the record and returning with success. This is working fine. Next I have implemented the ability to add new records, to do this I have a form at the end of the table, which submits post data then redirects back to the original page. Each of them work individually, but after I have used the form to add a new record, the inline editing stops to work. If I close the webpage and reopen it, it works fine again until I have used the form and it goes of the rails again. I have tried a number of solutions, clearing session data, giving the form a separate name, redirecting to an alternative page (which does work, but is not ideal as I want the form to redirect back to the original location ). Here is a sample of the view form data: <?php foreach($week->incomes as $income):?> <tr> <td><?php echo $income->name;?></td> <td width="70" style="text-align:right;" class="editableSingle income id<?php echo $income->id;?>">$<?php echo $income->cost;?></td> </tr> <?php endforeach;?> <?php echo form_open('budget/add/'.$week->id.'/income/index', 'class="form-vertical" id="add_income"'); ?> <tr> <td> <input type="text" name="name" class="input-small" placeholder="Name"> <input type="text" name="cost" class="input-small" placeholder="Cost"> </td> <td> <button type="submit" class="btn btn-small pull-right"><i class="icon-plus "></i></button> </td> </tr> <?php echo form_close(); ?> This is the javascript initialisation code: $(function(){ $.inlineEdit({ income: 'budget/update_income/', expense: 'budget/update_expense/' }, { animate: false, filterElementValue: function($o){ if ($o.hasClass('income')) { return $o.html().match(/\$(.+)/)[1]; } else if ($o.hasClass('expense')) { return $o.html().match(/\$(.+)/)[1]; } else { return $o.html(); } }, afterSave: function(o){ if (o.type == 'income') { $('.income.id' + o.id).prepend('$'); } if (o.type == 'expense') { $('.expense.id' + o.id).prepend('$'); } }, colors: { error:'green' } }); }); If I can provide any more information to clarify what I have attempted etc, let me know. Temporary Fix It seems I have come up with a work around, not ideal as I still am not sure what is causing the issue. I have created a method called redirect. public function redirect(){ redirect(''); } am now calling that after the form submit which has temporarily allows my multiple post submits to work.

    Read the article

  • Is there a better way to change user password in cakephp using Auth?

    - by sipiatti
    Hi, I am learning cakephp by myself. I tried to create a user controller with a changepassword function. It works, but I am not sure if this is the best way, and I could not googled up useful tutorials on this. Here is my code: class UsersController extends AppController { var $name = 'Users'; function login() { } function logout() { $this->redirect($this->Auth->logout()); } function changepassword() { $session=$this->Session->read(); $id=$session['Auth']['User']['id']; $user=$this->User->find('first',array('conditions' => array('id' => $id))); $this->set('user',$user); if (!empty($this->data)) { if ($this->Auth->password($this->data['User']['password'])==$user['User']['password']) { if ($this->data['User']['passwordn']==$this->data['User']['password2']) { // Passwords match, continue processing $data=$this->data; $this->data=$user; $this->data['User']['password']=$this->Auth->password($data['User']['passwordn']); $this->User->id=$id; $this->User->save($this->data); $this->Session->setFlash('Password changed.'); $this->redirect(array('controller'=>'Toners','action' => 'index')); } else { $this->Session->setFlash('New passwords differ.'); } } else { $this->Session->setFlash('Typed passwords did not match.'); } } } } password is the old password, passwordn is the new one, password2 is the new one retyped. Is there any other, more coomon way to do it in cake?

    Read the article

  • How to filter txt file by string with using batch

    - by Antediluvian
    Hello guys I know this kind of problem will be very easy for you but I am total beginner in batch mode. The question is how bat file code should look like to generate a new txt file from specific one . for example . I have report txt Displaying status for license file: 7788@Server01 License Server: server01 License In Use Free ------- ------ ---- Design* 1 6 (user1@host1) 127 server01 7788 4402 Assembly* 0 4 Pro 0 15 AdvSE 2 3 (user2@host2) AdvSE server01 7788 2706 (user3@host3) AdvSE server01 7788 1503 SingleSite_License 1 3 (user4@host4) SingleSite_License server01 7788 2003 Intra_CLIENT_License 1 4 (user2@host2) Intra_CLIENT_License server01 7788 2003 CAD 1 32 ^(user2@host2) CAD server01 7788 501 * = License Extensions - Available only on startup. ^ = Borrowed License. Press any key to continue . . . What I want to have in new file from this one are only lines : SingleSite_License 3 Intra_CLIENT_License 9 but both SingleSite_License and Intra_Client_License should be taken from 1st found string -other are not necessary. report txt can be different and licenses can be showed in different order . if it not possible - other solution can be just only Free value will be written in new txt file - f.e 3 and 9 . so the last string in line which contains specific words thank you for any tips

    Read the article

  • Catch a PHP Object Instantiation Error

    - by Rob Wilkerson
    It's really irking me that PHP considers the failure to instantiate an object a Fatal Error (which can't be caught) for the application as a whole. I have set of classes that aren't strictly necessary for my application to function--they're really a convenience. I have a factory object that attempts to instantiate the class variant that's indicated in a config file. This mechanism is being deployed for message storage and will support multiple store types: DatabaseMessageStore FileMessageStore MemcachedMessageStore etc. A MessageStoreFactory class will read the application's preference from a config file, instantiate and return an instance of the appropriate class. It might be easy enough to slap a conditional around the instantiation to ensure that class_exists(), but MemcachedMessageStore extends PHP's Memcached class. As a result, the class_exists() test will succeed--though instantiation will fail--if the memcached bindings for PHP aren't installed. Is there any other way to test whether a class can be instantiated properly? If it can't, all I need to do is tell the user which features won't be available to them, but let them continue one with the application. Thanks.

    Read the article

  • Keep the images downloaded in the listview during scrolling

    - by Paveliko
    I'm developing my first app and have been reading a LOT here. I've been trying to find a solution for the following issue for over a week with no luck. I have an Adapter that extends ArrayAdapter to show image and 3 lines of text in each row. Inside the getView I assign relevant information for the TextViews and use ImageLoader class to download image and assign it to the ImageView. Everything works great! I have 4.5 rows visible on my screen (out of total of 20). When I scroll down for the first time the images continue to download and be assigned in right order to the list. BUT when I scroll back the list looses all the images and start redrawing them again (0.5-1 sec per image) in correct order. From what I've been reading it's the standard list performance but I want to change it. I want that, once the image was downloaded, it will be "sticked" to the list for the whole session of the current window. Just like in Contacts list or in the Market. It is only 20 images (6-9kb each). Hope I managed to explain myself.

    Read the article

  • getting text that will be displayed to user from html

    - by gordatron
    Bit of a random one, i am wanting to have a play with some NLP stuff and I would like to: Get all the text that will be displayed to the user in a browser from HTML. My ideal output would not have any tags in it and would only have fullstops (and any other punctuation used) and new line characters, though i can tolerate a fairly reasonable amount of failure in this (random other stuff ending up in output). If there was a way of inserting a newline or full stop in situations where the content was likely not to continue on then that would be considered an added bonus. e.g: items in an ul or option tag could be separated by full stops (or to be honest just ignored). I am working Java, but would be interested in seeing any code that does this. I can (and will if required) come up with something to do this, just wondered if there was anything out there like this already, as it would probably be better than what I come up with in an afternoon ;-). An example of the code I might write if I do end up doing this would be to use a SAX parser to find content in p tags, strip it of any span or strong etc tags, and add a full stop if I hit a div or another p without having had a fullstop. Any pointers or suggestions very welcome.

    Read the article

  • Appropriate use of die()?

    - by letseatfood
    I create pages in my current PHP project by using the following template: <?php include 'bootstrap.php'; head(); ?> <!-- Page content here --> <?php foot(); ?> Is the following example an appropriate use of die()? Also, what sort of problems might this cause for me, if any? <?php include 'bootstrap.php'; head(); try { //Simulate throwing an exception from some class throw new Exception('Something went wrong!'); } catch(Exception $e) { ?> <p>Please fix the following errors:</p> <p><?php echo $e->getMessage(); ?></p> <?php foot(); die(); } //If no exception is thrown above, continue script doSomething(); doSomeOtherThing(); foot(); ?> ?> <?php foot(); ?> Basically, I have a script with multiple tasks on it and I am trying to set up a graceful way to notify the user of input errors while preventing the remaining portion of the script from executing. Thanks!

    Read the article

  • Goldbach theory in C

    - by nofe
    I want to write some code which takes any positive, even number (greater than 2) and gives me the smallest pair of primes that sum up to this number. I need this program to handle any integer up to 9 digits long. My aim is to make something that looks like this: Please enter a positive even integer ( greater than 2 ) : 10 The first primes adding : 3+7=10. Please enter a positive even integer ( greater than 2 ) : 160 The first primes adding : 3+157=160. Please enter a positive even integer ( greater than 2 ) : 18456 The first primes adding : 5+18451=18456. I don't want to use any library besides stdio.h. I don't want to use arrays, strings, or anything besides for the most basic toolbox: scanf, printf, for, while, do-while, if, else if, break, continue, and the basic operators (<,, ==, =+, !=, %, *, /, etc...). Please no other functions especially is_prime. I know how to limit the input to my needs so that it loops until given a valid entry. So now I'm trying to figure out the algorithm. I thought of starting a while loop like something like this: #include <stdio.h> long first, second, sum, goldbach, min; long a,b,i,k; //indices int main (){ while (1){ printf("Please enter a positive integer :\n"); scanf("%ld",&goldbach); if ((goldbach>2)&&((goldbach%2)==0)) break; else printf("Wrong input, "); } while (sum!=goldbach){ for (a=3;a<goldbach;a=(a+2)) for (i=2;(goldbach-a)%i;i++) first = a; for (b=5;b<goldbach;b=(b+2)) for (k=2;(goldbach-b)%k;k++) sum = first + second; } }

    Read the article

  • Downloading a webpage in C# example

    - by Chris
    I am trying to understand some example code on this web page: (http://www.csharp-station.com/HowTo/HttpWebFetch.aspx) that downloads a file from the internet. The piece of code quoted below goes through a loop getting chunks of data and saving them to a string until all the data has been downloaded. As I understand it, "count" contains the size of the downloaded chunk and the loop runs until count is 0 (an empty chunk of data is downloaded). My question is, isn't it possible that count could be 0 without the file being completely downloaded? Say if the network connection is interrupted, the stream may not have any data to read on a pass of the loop and count should be 0, ending the download prematurely. Or does ResStream.Read stop the program until it gets data? Is this the correct way to save a stream? int count = 0; do { // fill the buffer with data count = resStream.Read(buf, 0, buf.Length); // make sure we read some data if (count != 0) { // translate from bytes to ASCII text tempString = Encoding.ASCII.GetString(buf, 0, count); // continue building the string sb.Append(tempString); } } while (count 0); // any more data to read?

    Read the article

  • How to define 2-bit numbers in C, if possible?

    - by Eddy
    For my university process I'm simulating a process called random sequential adsorption. One of the things I have to do involves randomly depositing squares (which cannot overlap) onto a lattice until there is no more room left, repeating the process several times in order to find the average 'jamming' coverage %. Basically I'm performing operations on a large array of integers, of which 3 possible values exist: 0, 1 and 2. The sites marked with '0' are empty, the sites marked with '1' are full. Initially the array is defined like this: int i, j; int n = 1000000000; int array[n][n]; for(j = 0; j < n; j++) { for(i = 0; i < n; i++) { array[i][j] = 0; } } Say I want to deposit 5*5 squares randomly on the array (that cannot overlap), so that the squares are represented by '1's. This would be done by choosing the x and y coordinates randomly and then creating a 5*5 square of '1's with the topleft point of the square starting at that point. I would then mark sites near the square as '2's. These represent the sites that are unavailable since depositing a square at those sites would cause it to overlap an existing square. This process would continue until there is no more room left to deposit squares on the array (basically, no more '0's left on the array) Anyway, to the point. I would like to make this process as efficient as possible, by using bitwise operations. This would be easy if I didn't have to mark sites near the squares. I was wondering whether creating a 2-bit number would be possible, so that I can account for the sites marked with '2'. Sorry if this sounds really complicated, I just wanted to explain why I want to do this.

    Read the article

  • Check a list of packages to install with apt-get

    - by Joel
    I am writing a post-install script for Ubuntu in Perl (same script as seen here). One of the steps is to install a list of packages. The problem is that if apt-get install fails in some of many different ways for any one of the packages the script dies badly. I would like to prevent that from happening. This happens because of the ways that apt-get install fails for packages that it doesn't like. For example when I try to install a nonsense word (i.e. typed in the wrong package name) $ sudo apt-get install oblihbyvl Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package oblihbyvl but if instead the package name has been obsoleted (installing handbrake from ppa) $ sudo apt-get install handbrake Reading package lists... Done Building dependency tree Reading state information... Done Package handbrake is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'handbrake' has no installation candidate $ apt-cache search handbrake handbrake-cli - versatile DVD ripper and video transcoder - command line handbrake-gtk - versatile DVD ripper and video transcoder - GTK GUI I have tried parsing the results of apt-cache and apt-get -s install to try to catch all possibilities before doing the install, but I seem to keep finding new ways to allow failures to continue to the actual install system command. My question is, is there some facility either in Perl (e.g. a module, though I would like to avoid installing modules if possible as this is supposed to be the first thing run after a new install of Ubuntu) or apt-* or dpkg that would let me be sure that the packages are all available to be installed before installing and if not fail gracefully in some way that lets the user decide what to do?

    Read the article

  • `this` in global scope in ECMAScript 6

    - by Nathan Wall
    I've tried looking in the ES6 draft myself, but I'm not sure where to look: Can someone tell me if this in ES6 necessarily refers to the global object? Will this object have same members as the global scope? If you could answer for ES5 that would be helpful as well. I know this in global scope refers to the global object in the browser and in most other ES environments, like Node. I just want to know if that's the defined behavior by the spec or if that's extended behavior that implementers have added (and if this behavior will continue in ES6 implementations). In addition, is the global object always the same thing as the global scope? Or are there distinctions? Update - Why I want to know: I am basically trying to figure out how to get the global object reliably in ES5 & 6. I can't rely on window because that's specific to the browser, nor can I rely on global because that's specific to environments like Node. I know this in Node can refer to module in module scope, but I think it still refers to global in global scope. I want a cross-environment ES5 & 6 compliant way to get the global object (if possible). It seems like in all the environments I know of this in global scope does that, but I want to know if it's part of the actual spec (and so reliable across any environment that I may not be familiar with). I also need to know if the global scope and the global object are the same thing by the spec. In other words will all variables in global scope be the same as globalobject.variable_name?

    Read the article

  • jQuery animation loop not working

    - by Marko Ivanovski
    Hi, I'm trying to create a looping animation that starts on onmousedown and stops on onmouseout. The effect is a simple scroll that will continue looping until you release the mouse. I've created a function which performs the .animate method and it passes itself as a callback but the code only runs once. Here's the entire code: $(document).ready(function() { var $scroller = $("#scroller"); var $content = $("#content", $scroller); // lineHeight equal to 1 line of text var lineHeight = $content.css('line-height'); //Amount to scroll = 3 lines of text a time var amountToScroll = lineHeight.replace("px","")*3; var maxScroll = $content.height() - $scroller.height(); function scrollDown() { var topCoord = $content.css("top").replace("px",""); if(topCoord > -maxScroll) { if((-maxScroll-topCoord) > -amountToScroll) { $content.stop().animate({ top: -maxScroll }, 1000 ); } else { $content.stop().animate({ top: "-=" + amountToScroll }, 1000, function(){ scrollDown() } ); } } } function scrollUp() { var topCoord = $content.css("top").replace("px",""); if(topCoord < 0) { if(topCoord > -amountToScroll) { $content.stop().animate({ top: 0 }, 1000 ); } else { $content.stop().animate({ top: "+=" + amountToScroll }, 1000, function(){scrollUp()} ); } } } $("#scroll-down").mousedown(function() { scrollDown(); }); $("#scroll-down").mouseup(function() { $content.stop(); }); $("#scroll-up").mousedown(function() { scrollUp(); }); $("scroll-up").mouseup(function() { $content.stop(); }); });

    Read the article

  • XNA: What can cause SpriteBatch.End() to throw a NRE?

    - by Rosarch
    I don't understand what I'm doing wrong here: public void Draw(GameTime gameTime) // in ScreenManager { SpriteBatch.Begin(SpriteBlendMode.AlphaBlend); for (int i = 0; i < Screens.Count; i++) { if (Screens[i].State == Screen.ScreenState.HIDDEN) continue; Screens[i].Draw(gameTime); } SpriteBatch.End(); // null ref exception } SpriteBatch itself is not null. Some more context: public class MasterEngine : Microsoft.Xna.Framework.Game { public MasterEngine() { graphicsDeviceManager = new GraphicsDeviceManager(this); Components.Add(new GamerServicesComponent(this)); // ... spriteBatch = new SpriteBatch(graphicsDeviceManager.GraphicsDevice); screenManager = new ScreenManager(assets, gameEngine, graphicsDeviceManager.GraphicsDevice, spriteBatch); } //... protected override void Draw(GameTime gameTime) { screenManager.Draw(gameTime); // calls the problematic method base.Draw(gameTime); } } Am I failing to initialize something properly? UPDATE: As an experiment, I tried this to the constructor of MasterEngine: spriteBatch = new SpriteBatch(graphicsDeviceManager.GraphicsDevice); spriteBatch.Begin(); spriteBatch.DrawString(assets.GetAsset<SpriteFont>("calibri"), "ftw", new Vector2(), Color.White); spriteBatch.End(); This does not cause a NRE. hmm.... UPDATE 2: This does cause an NRE: protected override void Draw(GameTime gameTime) { spriteBatch.Begin(); spriteBatch.End(); // boned here //screenManager.Draw(gameTime); base.Draw(gameTime); }

    Read the article

  • How to differentiate between exceptions i can show the user, and ones i can't?

    - by Ian Boyd
    i have some business logic that traps some logically invalid situations, e.g. trying to reverse a transaction that was already reversed. In this case the correct action is to inform the user: Transaction already reversed or Cannot reverse a reversing transaction or You do not have permission to reverse transactions or This transaction is on a session that has already been closed or This transaction is too old to be reversed The question is, how do i communicate these exceptional cases back to the calling code, so they can show the user? Do i create a separate exception for each case: catch (ETransactionAlreadyReversedException) MessageBox.Show('Transaction already reversed') catch (EReversingAReversingTransactionException) MessageBox.Show('Cannot reverse a reversing transaction') catch (ENoPermissionToReverseTranasctionException) MessageBox.Show('You do not have permission to reverse transactions') catch (ECannotReverseTransactionOnAlredyClosedSessionException) MessageBox.Show('This transaction is on a session that has already been closed') catch (ECannotReverseTooOldTransactionException) MessageBox.Show('This transaction is too old to be reversed') Downside for this is that when there's a new logical case to show the user: Tranasctions created by NSL cannot be reversed i don't simply show the user a message, and instead it leaks out as an unhandled excpetion, when really it should be handled with another MessageBox. The alternative is to create a single exception class: `EReverseTransactionException` With the understanding that any exception of this type is a logical check, that should be handled with a message box: catch (EReverseTransactionException) But it's still understood that any other exceptions, ones that involve, for example, an memory ECC parity error, continue unhandled. In other words, i don't convert all errors that can be thrown by the ReverseTransaction() method into EReverseTransactionException, only ones that are logically invalid cause of the user.

    Read the article

  • Query distinct list of choices for Django form with App Engine Datastore

    - by Brian
    I've been trying to figure this out for hours across a couple of days, and can not get it to work. I've been everywhere. I'll continue trying to figure it out, but was hoping for a quicker solution. I'm using App Engine datastore + Django. Using a query in a view and custom forms, I was able to get a list to the form but then I was not able to post. I have been trying to figure out how to dynamically add the choices as part of the Django form... I've tried various ways with no success. Help! Below are the two models. I'd like to get a distinct list of address_id to show in the location field in InfoForm. This fields could (and maybe should) be named the same, but I thought it'd be easier if they were named different. class Info(db.Model): user = db.UserProperty() location = db.StringProperty() info = db.StringProperty() created = db.DateTimeProperty(auto_now_add=True) modified = db.DateTimeProperty(auto_now=True) class Locations(db.Model): user = db.UserProperty() address_id = db.StringProperty() address = db.StringProperty() class InfoForm(djangoforms.ModelForm): info = forms.ChoiceField(choices=INFO_CHOICES) location = forms.ChoiceField() class Meta: model = Info exclude = ['user','created','modified']

    Read the article

< Previous Page | 534 535 536 537 538 539 540 541 542 543 544 545  | Next Page >