Search Results

Search found 13430 results on 538 pages for 'easy'.

Page 494/538 | < Previous Page | 490 491 492 493 494 495 496 497 498 499 500 501  | Next Page >

• Load on page inside another onClick

  - by Robin I Knight

  Hello, I need to include the content, scripts, forms and dynamic abilities of one page in another onClick. Take a look at http://www.divethegap.com/scuba-diving-programmes-dive-the-gap/dahab-master-scuba-diver.html Then follow one of the links that says 'Beginner' 'Open Water Diver' etc.... You will find a PHP page with a series of options. It is an adaption of the wordpress blog system to produce only specific options for specific programmes by considering each type of each diving programme a category and then displaying only results from that category. You will see that each option is also a collapsible panel and there are also several javascripts that calculate durations, quantities and prices. There is also a validating webform at the end. Now go back to the first page. What I would like to do is include all the content from the second page after the main header inside tabbed panels on the first page so that the customers can immidietly see everything that is included. Essentially the options on the first page would become a series of tabs. The only way I can see to do this is with an iFrame as each option would need a unique URL ending (that is .php?cat=26 or .php?cat=27). THe problem is that the collapsible panels will not work with an iFrame as the iFrame will not resize when the panels open. There were also some calculation problems, but I think that was more down to me staring at the screen for the last 3 hours not remembering to include everything. I have tried it with resizing iframe SSI scripts and have got nowhere. I tried actually embedding it in the page better with a ajax script, but that left behind all the scripts that make it work. I checked with full URL's on everything and it would not take work with any scripts. I know that you could just make the whole page reload but then the user would be at the top of the page again, and even if another script was applied to slowly bring them down again it would not be anything near as easy to use as if it was like tabbed panels. Any ideas. Kind Regards,

  Read the article

• Choosing the right .NET architecture. WCF? WPF/Forms, ASP.NET (MVC)?

  - by Tommy Jakobsen

  I’m in the situation that I have to design and implement a rather big system from the bottom. I’m having some (a lot actually) questions about the architecture that I would like your comments and thoughts on. I don’t hope that I’ve written too much here, but I wanted to give you all an idea of what the system is. Quick info about the applications, read if you want: I can’t share much detail about the project, but basically it’s a system where we offer our customer a service to manage their users. We have a hotline where the users call and our hotline uses an (windows) application (intranet) to manage the user’s data, etc. The customer also has a web application where they can see reports, information about their business and users, and the ability to modify their data. Modifying data is not just user data like address and so, but also information about the products/services the user has, which can be complicated. The applications will be built on Microsoft .NET Framework 4, with a MS SQL Server 2008 database. There will be a few applications that have to access this database, such as: Intranet application (used by us and our hotline) Customer web application type 1 Customer web application type 2 Customer web application type n different applications) … Now my big problem is what .NET parts I should use for such a system. For the “backend” I’ve considered using Windows Communication Foundation: Would WCF be a good choice? The intranet application will be an application that has to edit lots of records in the database. It has to be easy to navigate using the keyboard (fast to work with). Has a feature such as “find customer, find that, lookup this, choose this and update that”. What would be the best choice to develop this application in? Would it be WPF or good old Windows Forms? I don’t need all of the fancy graphics features in WPF, like 3D, but the application has to look nice (maybe something like the new Visual Studio/Office tools). And the same question goes for the web pages. They have much the same work to do, but not as many features as the intranet application, and not the same amount of data (much less). That is my questions for now. I’m hoping to get a discussion going that will open my eyes to some of these technologies, helping me decide architecture to go with. I would like to say thanks in advance, and let you all know that any thoughts will be much appreciated.

  Read the article

• Excel UDF calculation should return 'original' value

  - by LeChe

  Hi all, I've been struggling with a VBA problem for a while now and I'll try to explain it as thoroughly as possible. I have created a VSTO plugin with my own RTD implementation that I am calling from my Excel sheets. To avoid having to use the full-fledged RTD syntax in the cells, I have created a UDF that hides that API from the sheet. The RTD server I created can be enabled and disabled through a button in a custom Ribbon component. The behavior I want to achieve is as follows: If the server is disabled and a reference to my function is entered in a cell, I want the cell to display Disabled If the server is disabled, but the function had been entered in a cell when it was enabled (and the cell thus displays a value), I want the cell to keep displaying that value If the server is enabled, I want the cell to display Loading Sounds easy enough. Here is an example of the - non functional - code: Public Function RetrieveData(id as Long) Dim result as String // This returns either 'Disabled' or 'Loading' result = Application.Worksheet.Function.RTD("SERVERNAME", "", id) RetrieveData = result If(result = "Disabled") Then // Obviously, this recurses (and fails), so that's not an option If(Not IsEmpty(Application.Caller.Value2)) Then // So does this RetrieveData = Application.Caller.Value2 End If End If End Function The function will be called in thousands of cells, so storing the 'original' values in another data structure would be a major overhead and I would like to avoid it. Also, the RTD server does not know the values, since it also does not keep a history of it, more or less for the same reason. I was thinking that there might be some way to exit the function which would force it to not change the displayed value, but so far I have been unable to find anything like that. Any ideas on how to solve this are greatly appreciated! Thanks, Che EDIT: By popular demand, some additional info on why I want to do all this: As I said, the function will be called in thousands of cells and the RTD server needs to retrieve quite a bit of information. This can be quite hard on both network and CPU. To allow the user to decide for himself whether he wants this load on his machine, he or she can disable the updates from the server. In that case, he or she should still be able to calculate the sheets with the values currently in the fields, yet no updates are pushed into them. Once new data is required, the server can be enabled and the fields will be updated. Again, since we are talking about quite a bit of data here, I would rather not store it somewhere in the sheet. Plus, the data should be usable even if the workbook is closed and loaded again.

  Read the article

• feeling insufficient while looking for a programming job ...

  - by user325661

  Hello everybody It's really dream to be programmer for me.So i always wanted to be .I had so small knowledges from commodore basic which i couldn't figure out anything in it .Then i tried to learn Visual basic 6 by myself and result wasn't good as i expected because i even didn't understand classes.Then i left to learning programming and to dream to be programmer. But challenge hadn't finished yet . After all of these i started to learn c# and i did chess engine which i hadn't believe that i can create one.I sometimes feel that i understand many thing about programming like knowing classes ,inheritance,abstract class and methods why exist , interfaces ,extension methods ,static classes ,threads. but i am not expert all in it . i just know that as i need . i don't know still i will learn many thing about these.i have also learned html, css2 , php and database concepts a little sql ,tables relations between primary keys etc but i haven't used them in praticaly . i just did some samples so i feel i am lack of knowledges. As a result still i can't evaluate my skills and can't decide what is my level.I just feel myself one step ahead of junior sometimes :) . Still can't decide that it is time to job seeking. While searching job on web i have never seen a junior advertisement. All looking for a good experiencing one.Nobody care about juniors. When found job advertisement which i feel sufficient myself a little then i start to feel that i think i can't do what they want from me and loosing job after have it in short time would leave many crap feelings into my low self-confidence. Please advise me something ... Also i want to ask some of concentrate questions. 1) If i enter a job which i can't provide their expectations should be in employers responsibility to test me while apply the job ? 2) If i answer "yes , i can " questions which is abstract(for example: can u do something like this) would be my responsibility ? Because such abstract questions is not clear and can't know before start it what i really can or not . 3) i have no professional experiences in this job so i even don't know how teams working on projects but a friend of me said that programmers only write method bodies while seniors create all project.So it looks what i can do really easy but i feel that small companies doesn't work like this so it is better work in a big company for starting who has seniors? 4)last applied job was looking for c# . net developer but then i learn that they need .net web developer.Does it take long time to learn specific sides of web programming while knowing c# desktop programming ? Thanks for all answers since now.

  Read the article

• dynamiclly schedule a lead sales agent

  - by Josh

  I have a website that I'm trying to migrate from classic asp to asp.net. It had a lead schedule, where each sales agent would be featured for the current day, or part of the day.The next day a new agent would be scheduled. It was driven off a database table that had a row for each day in it. So to figure out if a sales agent would show on a day, it was easy, just find today's date in the table. Problem was it ran out rows, and you had to run a script to update the lead days 6 months at a time. Plus if there was ever any change to the schedule, you had to delete all the rows and re-run the script. So I'm trying to code it where sql server figures that out for me, and no script has to be ran. I have a table like so CREATE TABLE [dbo].[LeadSchedule]( [leadid] [int] IDENTITY(1,1) NOT NULL, [userid] [int] NOT NULL, [sunday] [bit] NOT NULL, [monday] [bit] NOT NULL, [tuesday] [bit] NOT NULL, [wednesday] [bit] NOT NULL, [thursday] [bit] NOT NULL, [friday] [bit] NOT NULL, [saturday] [bit] NOT NULL, [StartDate] [smalldatetime] NULL, [EndDate] [smalldatetime] NULL, [StartTime] [time](0) NULL, [EndTime] [time](0) NULL, [order] [int] NULL, So the user can schedule a sales agent depending on their work schedule. Also if they wanted to they could split certain days, or sales agents by time, So from Midnight to 4 it was one agent, from 4-midnight it was another. So far I've tried using a numbers table, row numbers, goofy date math, and I'm at a loss. Any suggestions on how to handle this purely from sql code? If it helps, the table should always be small, like less than 20 never over 100. update After a few hours all I've managed to come up with is the below. It doesn't handle filling in days not available or times, just rotates through all the sales agents with leadTable as ( select leadid,userid,[order],StartDate, case DATEPART(dw,getdate()) when 1 then sunday when 2 then monday when 3 then tuesday when 4 then wednesday when 5 then thursday when 6 then friday when 7 then saturday end as DayAvailable , ROW_NUMBER() OVER (ORDER BY [order] ASC) AS ROWID from LeadSchedule where GETDATE()>=StartDate and (CONVERT(time(0),GETDATE())>= StartTime or StartTime is null) and (CONVERT(time(0),GETDATE())<= EndTime or EndTime is null) ) select userid, DATEADD(d,(number+ROWID-2)*totalUsers,startdate ) leadday from (select *, (select COUNT(1) from leadTable) totalUsers from leadTable inner join Numbers on 1=1 where DayAvailable =1 ) tb1 order by leadday asc

  Read the article

• What are those little useful ,customize/enhanced php functions that you wish you knew about 2 years

  - by I Like PHP

  Hello All, i like to work in php bcoz it's just amazing language. please share basic, useful, enhanced and customize function that make things better and easy in php and must be used in our all PHP project, i m sharing some of them please share your customize function that may be useful for everyone alternative/ enhanced print_r() and var_dump() function watch( $what ) { echo '<pre>'; if ( is_array( $what ) ) { print_r ( $what ); } else { var_dump ( $what ); } echo '</pre>'; } usage: 1. watch($_POST); // to see all post variable 2. watch($array); // to see any variable may b array, string or a variable enhanced mysql_escape_string() for multidimensional array to prevent sql injection function recursive_escape(&$value) { if (is_array($value)) array_map('recursive_escape', $value); else $value = mysql_escape_string($value); } usage array_map('recursive_escape', $_POST); ---------------------For encoding Get variables-------------------------------------- function nkode($k) { if ( is_array( $k ) ) return array_map("base64_encode",$k); else return base64_encode($k); } ---------------------for decoding varaibles from GET--------------------------------- function dkode($k) { if ( is_array( $k ) ) return array_map("base64_decode",$k); else return base64_decode($k); } Usage <a href="somelink.php?pid=<?php echo nkode($someid)?>"> and on next page(somelink.php) $findID=dkode($_GET[pid]); date convert to mm/dd/yyyy to yyyy-mm-dd( if we use date datatype in mysql) and also change into mm/dd/yyyy to disply on page function dateconvert($date,$func) { if ($func == 1){ //insert conversion list($month, $day, $year) = split('[/.-]', $date); $date = "$year-$month-$day"; return $date; } if ($func == 2){ //output conversion list($year, $month, $day) = split('[-.]', $date); $date = "$month/$day/$year"; return $date; } } usage $firstDate=dateconvert($_POST['firstdate'],1); // for insertion in database $showDate=dateconvert($fetch->date_field,2) // to display on browser to clean data before doing some action with that variable function cleanID($data) { $success=0; $data=trim($data); $data=strtolower($data); $data=strip_tags($data); return $data; } usage cleanID($_POST[username]); cleanID($_GET[pid]); please share any basic function that must be used , and please give me some suggestion to make above function more better Thanks

  Read the article

• Validating against a Schema with JAXB

  - by fwgx

  I've been looking for solutions to this problem for far too long considering how easy it sounds so I've come for some help. I have an XML Schema which I have used with xjc to create my JAXB binding. This works fine when the XML is well formed. Unfortunately it also doesn't complain when the XML is not well formed. I cannot figure out how to do proper full validation against the schema when I try to unmarshall an XML file. I have managed to use a ValidationEventCollector to handle events, which works for XML parsing errors such as mismatched tags but doesn't raise any events when there is a tag that is required but is completely absent. From what I have seen validation can be done againsta schema, but you must know the path to the schema in order to pass it into the setSchema() method. The problem I have is that the path to the schema is stored in the XML header and I can't knwo at run time where the schema is going to be. Which is why it's stored in the XML file: <?xml version="1.0" encoding="utf-8"?> <DDSSettings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="/a/big/long/path/to/a/schema/file/DDSSettings.xsd"> <Field1>1</Field1> <Field2>-1</Field2> ...etc Every example I see uses setValidating(true), which is now deprecated, so throws an exception. This is the Java code I have so far, which seems to only do XML validation, not schema validation: try { JAXBContext jc = new JAXBContext() { private final JAXBContext jaxbContext = JAXBContext.newInstance("blah"); @Override public Unmarshaller createUnmarshaller() throws JAXBException { Unmarshaller unmarshaller = jaxbContext.createUnmarshaller(); ValidationEventCollector vec = new ValidationEventCollector() { @Override public boolean handleEvent(ValidationEvent event) throws RuntimeException { ValidationEventLocator vel = event.getLocator(); if (event.getSeverity() == event.ERROR || event.getSeverity() == event.FATAL_ERROR) { String error = "XML Validation Exception: " + event.getMessage() + " at row: " + vel.getLineNumber() + " column: " + vel.getColumnNumber(); System.out.println(error); } m_unmarshallingOk = false; return false; } }; unmarshaller.setEventHandler(vec); return unmarshaller; } @Override public Marshaller createMarshaller() throws JAXBException { throw new UnsupportedOperationException("Not supported yet."); } @Override @SuppressWarnings("deprecation") public Validator createValidator() throws JAXBException { throw new UnsupportedOperationException("Not supported yet."); } }; Unmarshaller unmarshaller = jc.createUnmarshaller(); m_ddsSettings = (com.ultra.DDSSettings)unmarshaller.unmarshal(new File(xmlfileName)); } catch (UnmarshalException ex) { Logger.getLogger(UniversalDomainParticipant.class.getName()).log( Level.SEVERE, null, ex); } catch (JAXBException ex) { Logger.getLogger(UniversalDomainParticipant.class.getName()).log( Level.SEVERE, null, ex); } So what is the proper way to do this validation? I was expecting there to be a validate() method on the JAXB generated classes, but I guess that would be too simple for Java.

  Read the article

• Why does extend() engage in bizarre behaviour when passed the same list twice?

  - by intuited

  I'm pretty confused by one of the subtleties of the vimscript extend() function. If you use it to extend a list with another list, it does pretty much what you'd expect, which is to insert the second list into the first list at the index given by the third parameter: let list1 = [1,2,3,4,5,6] | echo extend(list1,[1,2,3,4,5,6],5) " [1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 6] However if you give it the same list twice it starts tripping out a bit. let list1 = [1,2,3,4,5,6] | echo extend(list1,list1,0) " [1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6] let list1 = [1,2,3,4,5,6] | echo extend(list1,list1,1) " [1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6] let list1 = [1,2,3,4,5,6] | echo extend(list1,list1,2) " [1, 2, 1, 2, 1, 2, 1, 2, 3, 4, 5, 6] let list1 = [1,2,3,4,5,6] | echo extend(list1,list1,3) " [1, 2, 3, 1, 2, 3, 1, 2, 3, 4, 5, 6] let list1 = [1,2,3,4,5,6] | echo extend(list1,list1,4) " [1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 5, 6] let list1 = [1,2,3,4,5,6] | echo extend(list1,list1,5) " [1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 6] let list1 = [1,2,3,4,5,6] | echo extend(list1,list1,6) " [1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6] Extra-confusingly, this behaviour applies when the list is referenced with two different variables: let list1 = [1,2,3,4,5,6] | let list2 = list1 | echo extend(list1,list2,4) " [1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 5, 6] This is totally bizarre to me. I can't fathom a use for this functionality, and it seems like it would be really easy to invoke it by accident when you just wanted to insert one list into another and didn't realize that the variables were referencing the same array. The documentation says the following: If they are |Lists|: Append {expr2} to {expr1}. If {expr3} is given insert the items of {expr2} before item {expr3} in {expr1}. When {expr3} is zero insert before the first item. When {expr3} is equal to len({expr1}) then {expr2} is appended. Examples: :echo sort(extend(mylist, [7, 5])) :call extend(mylist, [2, 3], 1) When {expr1} is the same List as {expr2} then the number of items copied is equal to the original length of the List. E.g., when {expr3} is 1 you get N new copies of the first item (where N is the original length of the List). Does this make sense in a way that I'm not getting, or is it just an eccentricity?

  Read the article

• What is the best way to read and write cXML documents in C# ?

  - by tetranz

  I know this is a vague open ended question. I'm hoping to get some general direction. I need to add cXML punchout to an ASP.NET C# site / application. This is replacing something that I wrote years ago in ColdFusion. I'm a reasonably experienced C# developer but I haven't done much with XML. There seems to be lots of different options for processing XML in .NET. Here's the open ended question: Assuming that I have an XML document in some form, eg a file or a string, what is the best way to read it into my code? I want to get the data and then query databases etc. The cXML document size and our traffic volumes are easily small enough so that loading the a cXML document into memory is not a problem. Should I: 1) Manually build classes based on the dtd and use the XML Serializer? 2) Use a tool to generate classes. There are sample cXML files downloadable from Ariba.com. I tried xsd.exe to generate an xsd and then xsd.exe /c to generate classes. When I try to deserialize I get errors because there seems to be "confusion" around whether some elements should be single values or arrays. I tried the CodeXS online tool but that gives errors in it's log and errors if I try to deserialize a sample document. 2) Create a dataset and ReadXml()? 3) Create a typed dataset and ReadXml()? 4) Use Linq to XML. I often use Linq to Objects so I'm familiar with Linq in general but I'm struggling to see what it gives me in this situation. 5) Some other means. I guess I need to improve my understanding of XML in general but even so ... am I missing some obvious way of doing this? In the old ColdFusion site I found a free component ("tag") which basically ignored any schema and read the XML into a "structure" which is essentially a series of nested hash tables which was then easy to read in code. That was probably quite sloppy but it worked. I also need to generate XML files from my C# objects. Maybe Linq to XML will be good for that. I could start with a default "template" document and manipulate it before saving. Thanks for any pointers ...

  Read the article

• Jquery image preview thumbnail doesn't seem to work....

  - by Pandiya Chendur

  I just tried the tooltip like this Easy image preview... But i cant get it to work.... I used this, <style> body { margin:0; padding:40px; background:#fff; font:80% Arial, Helvetica, sans-serif; color:#555; line-height:180%; } h1{ font-size:180%; font-weight:normal; color:#555; } h2{ clear:both; font-size:160%; font-weight:normal; color:#555; margin:0; padding:.5em 0; } a{ text-decoration:none; color:#f30; } p{ clear:both; margin:0; padding:.5em 0; } pre{ display:block; font:100% "Courier New", Courier, monospace; padding:10px; border:1px solid #bae2f0; background:#e3f4f9; margin:.5em 0; overflow:auto; width:800px; } img{border:none;} ul,li{ margin:0; padding:0; } li{ list-style:none; float:left; display:inline; margin-right:10px; } /* */ #preview{ position:absolute; border:1px solid #ccc; background:#333; padding:5px; display:none; color:#fff; } /* */ </style> <script type="text/javascript" src="jquery.js"></script> <ul> <li> <a href="Images/4.jpg" class="preview" title="Lake and a mountain"> <img src="Images/4s.jpg" alt="gallery thumbnail" /> </a> </li> </ul> and included style... Nothing happens when i hover over the anchor tag....

  Read the article

• Issues loading Jquery (Galleria) script from inside an i-frame (beginner javascript?)

  - by 103188530284789248582

  Hello, first of all - I'm not entirely new to javascript, but am not fluent in it as I am with html and css, and am especially new to jQuery... so please excuse me if this questions seems easy or obvious, but after days of google I still have no solution to the problem... using jQuery 1.4.2.min, jQuery-ui-1.8.1 .... the site in question: http://homecapture.ca/sets/project_index.html The scenario: I have a tabbed menu generated from an unordered list, when a menu item is clicked it reveals an iframe which links to the page containing an image gallery. I am using jQuery UI tabs for the tabbed menu, and the galleries to which I'm linking are jQuery Galleria pages, automatically generated with Jalbum. The problem: The galleria plug-in only works normally from inside of the containing iframe in Chrome, has inconsistent behaviour in IE8 (seems to work in my local copy, but won't load properly online), and is not loaded properly in Firefox. Instead of displaying a thumbnail area and the first large image, the Galleria page shows the first thumbnail only, then when it is clicked the image it links to, but if you right-click and go Back, the iframe content shows up as a properly rendered Galleria page. Jalbum generates more script in the < head of the page in addition to linking to jquery and the galleria plug-in. All of it seems to be in charge of the gallery navigation , and I have relocated it to the < body of the page, in an effort to make it load after the parent page scripts, and together with the gallery content. At this point I am not sure what else I could do to solve the problem, without digging around in all or some of the library and pluging .js files (which I am not knowledgeable enough to do without some pointers). Has anyone dealt with a similar issue? I'm seeing some solutions for manipulating iframe content from a parent page with jQuery on here, is that what I should be researching instead? Thanks in advance for all the help! ps. I tried posting some code, but it seems I do not have enough 'reputation' for things to work right on here either :)

  Read the article

• Want to set 'src' of script to my IP-Won't load in Safari or Chrome. Relative link asp.netmvc

  - by Ozaki

  I have a script that links to the server I am hosting (IP can change) usually I would just use for links: var url ='http://' + window.location.hostname + 'end of url'; But in this case it isnt appearing to be so easy. I have tried: (1) $('#scriptid').attr('src', url); as well as: (2) var script = document.createElement( 'script' ); script.type = 'text/javascript'; script.src = url; $("#insert").append( script ); Now case (2) works loads the script runs the script. But when at the end of my script it hits the 'write data' it decides to replace the entire page with just the data. Any idea on how I can do this? Note: I am using plain html not ASP. With ASP backend that is just the way it has to be. Ok it now is <script src="myscript.js"></script> C# router.AddAsyncRoute("myscript.js"...... It workes in IE & FF. But I get blank pages in Chrome & Safari. I am using document.write to write a script onto my page. Any ideas why Chrome & Safari don't like this? I am so far assuming that in Crhome & Safari it takes longer to run the script therefore launching the document.write after the DOM has loaded therefore replacing the page with a blank one. edit the script im trying to run is a modification of: d = new dTree('d'); d.add(0,-1,'My example tree'); d.add(1,0,'Node 1','default.html'); d.add(2,0,'Node 2','default.html'); d.add(3,1,'Node 1.1','default.html'); d.add(4,0,'Node 3','default.html'); d.add(5,3,'Node 1.1.1','default.html') document.write(d); Any ideas how I can get around this? I am not to sure how to implement an appenChild in this case as the script is changing constantly with live data. So every refresh it will generally have changed some...

  Read the article

• java timer on current instance

  - by hspim

  import java.util.Scanner; import java.util.Timer; import java.util.TimerTask; public class Boggle { Board board; Player player; Timer timer; boolean active; static Scanner in = new Scanner(System.in); public Boggle() { board = new Board(4); timer = new Timer(); } public void newGame() { System.out.println("Please enter your name: "); String line = in.nextLine(); player = new Player(line); active = true; board.shuffle(); System.out.println(board); timer.schedule(new timesUP(), 20000); while(active) { String temp = in.nextLine(); player.addGuess(temp); } } public void endGame() { active = false; int score = Scoring.calculate(player, board); System.out.println(score); } class timesUP extends TimerTask { public void run() { endGame(); } } public static void main(String[] args) { Boggle boggle = new Boggle(); boggle.newGame(); } } I have the above class which should perform a loop for a given length of time and afterwards invoke an instance method. Essentially I need the loop in newGame() to run for a minute or so before endGame() is invoked on the current instance. However, using the Timer class I'm not sure how I would invoke the method I need on the current instance since I can't pass any parameters to the timertasks run method? Is there an easy way to do this or am I going about this the wrong way? (note: this is a console project only, no GUI) ========== code edited I've changed the code to the above following the recommendations, and it works almost as I expect however the thread still doesnt seem to end properly. I was the while loop would die and control would eventually come back to the main method. Any ideas?

  Read the article

• sendmail and MX records when mail server is not on web host

  - by Jim Nelson

  This is a problem I'm sure is easy to fix, but I've been banging my head on it all day. I'm developing a new web site for a client. The web site resides at (this is an example) website.com. I have a PHP form script to email visitors' requests to [email protected]. When I coded this on a staging server on a different domain, all worked fine. When I moved it to website.com, the mail messages never arrived. The web server is on a virtual host with a major ISP. Here's what I've learned since then: My client's mail server is Microsoft Exchange on a box physically in their office. Whenever someone on the outside world emails [email protected], the mail arrives. But if the web server sends to the same email address, it fails every time. This is not a PHP problem. I secure shell in to the web server and have tested this both with sendmail and the UNIX mail application. I've also tested it by emailing various email accounts from the shell. I can email myself, for example, just nobody at the website.com domain. In short, when I'm logged in to website.com, mail to [email protected], [email protected], [email protected] all fail. All other addresses work fine. What I've discovered is those dropped emails are routed to the web server's "catchall" account where they sit in its inbox. I've done an MX lookup on website.com. The MX record points to mailsec.website.com. I can telnet to mailsec.website.com port 25 and see the SMTP server. It appears to me that website.com isn't doing an MX lookup when it's sending mail to [email protected]. My theory is that it recognizes the domain as local, sees that there's no "requests" user account to deliver it to, and drops the mail into the catchall account. What I want is to force sendmail to do the MX lookup and send the message on to the Exchange server. I'm at wit's end here. I can't figure out how to do this. For that matter, I may be way off base here and have misdiagnosed this entirely. Internet mail and MX has always seemed a black art to me, and my ignorance is certainly showing in this question.

  Read the article

• show/hide html table columns using css

  - by Art Peterson

  I want to display a basic html table with controls to toggle showing/hiding of additional columns: <table id="mytable"> <tr> <th>Column 1</th> <th class="col1">1a</th> <th class="col1">1b</th> <th>Column 2</th> <th class="col2">2a</th> <th class="col2">2b</th> </tr> <tr> <td>100</td> <td class="col1">40</td> <td class="col1">60</td> <td>200</td> <td class="col2">110</td> <td class="col2">90</td> </tr> </table> So Column 1 and Column 2 will be the only columns displayed by default - but when you click on the Column 1 I want 1a and 1b to toggle, and same with Column 2 with 2a and 2b. I may end up with more columns and lots of rows - so any javascript looping approaches have been too slow to work with when I tested. The only approach that seems to be fast enough is to set up some css like this: table.hide1 .col1 { display: none; } table.hide2 .col2 { display: none; } table.hide3 .col3 { display: none; } table.show1 .col1 { display: table-cell; } table.show2 .col2 { display: table-cell; } table.show3 .col3 { display: table-cell; } And then set up onClick function calls on the table header cells that will trigger a toggle - and determine which css class to set "mytable" to that will create the toggle effect that I'm looking for. Is there an easy way to set this up so that the code can work for n # of columns?

  Read the article

• What is a good platform for building a game framework targetting both web and native languages?

  - by fuzzyTew

  I would like to develop (or find, if one is already in development) a framework with support for accelerated graphics and sound built on a system flexible enough to compile to the following: native ppc/x86/x86_64/arm binaries or a language which compiles to them javascript actionscript bytecode or a language which compiles to it (actionscript 3, haxe) optionally java I imagine, for example, creating an API where I can open windows and make OpenGL-like calls and the framework maps this in a relatively efficient manner to either WebGL with a canvas object, 3d graphics in Flash, OpenGL ES 2 with EGL, or desktop OpenGL in an X11, Windows, or Cocoa window. I have so far looked into these avenues: Building the game library in haXe Pros: Targets exist for php, javascript, actionscript bytecode, c++ High level, object oriented language Cons: No support for finally{} blocks or destructors, making resource cleanup difficult C++ target does not allow room for producing highly optimized libraries -- the foreign function interface requires all primitive types be boxed in a wrapper object, as if writing bindings for a scripting language; these feel unideal for real-time graphics and audio, especially exporting low-level functions. Doesn't seem quite yet mature Using the C preprocessor to create a translator, writing programs entirely with macros Pros: CPP is widespread and simple to use Cons: This is an arduous task and probably the wrong tool for the job CPP implementations differ widely in support for features (e.g. xcode cpp has no variadic macros despite claiming C99 compliance) There is little-to-no room for optimization in this route Using llvm's support for multiple backends to target c/c++ to web languages Pros: Can code in c/c++ LLVM is a very mature highly optimizing compiler performing e.g. global inlining Targets exist for actionscript (alchemy) and javascript (emscripten) Cons: Actionscript target is closed source, unmaintained, and buggy. Javascript targets do not use features of HTML5 for appropriate optimization (e.g. linear memory with typed arrays) and are immature An LLVM target must convert from low-level bytecode, so high-level constructs are lost and bloated unreadable code is created from translating individual instructions, which may be more difficult for an unprepared JIT to optimize. "jump" instructions cause problems for languages with no "goto" statements. Using libclang to write a translator from C/C++ to web languages Pros: A beautiful parsing library providing easy access to the code structure Can code in C/C++ Has sponsored developer effort from Apple Cons: Incomplete; current feature set targets IDEs. Basic operators are unexposed and must be manually parsed from the returned AST element to be identified. Translating code prior to compilation may forgo optimizations assumed in c/c++ such as inlining. Creating new code generators for clang to translate into web languages Pros: Can code in C/C++ as libclang Cons: There is no API; code structure is unstable A much larger job than using libclang; the innards of clang are complex Building the game library in Common Lisp Pros: Flexible, ancient, well-developed language Extensive introspection should ease writing translators Translators exist for at least javascript Cons: Unfamiliar language No standardized library functions, widely varying implementations Which of these avenues should I pursue? Do you know of any others, or any systems that might be useful? Does a general project like this exist somewhere already? Thank you for any input.

  Read the article

• java concurrency: many writers, one reader

  - by Janning

  I need to gather some statistics in my software and i am trying to make it fast and correct, which is not easy (for me!) first my code so far with two classes, a StatsService and a StatsHarvester public class StatsService { private Map<String, Long> stats = new HashMap<String, Long>(1000); public void notify ( String key ) { Long value = 1l; synchronized (stats) { if (stats.containsKey(key)) { value = stats.get(key) + 1; } stats.put(key, value); } } public Map<String, Long> getStats ( ) { Map<String, Long> copy; synchronized (stats) { copy = new HashMap<String, Long>(stats); stats.clear(); } return copy; } } this is my second class, a harvester which collects the stats from time to time and writes them to a database. public class StatsHarvester implements Runnable { private StatsService statsService; private Thread t; public void init ( ) { t = new Thread(this); t.start(); } public synchronized void run ( ) { while (true) { try { wait(5 * 60 * 1000); // 5 minutes collectAndSave(); } catch (InterruptedException e) { e.printStackTrace(); } } } private void collectAndSave ( ) { Map<String, Long> stats = statsService.getStats(); // do something like: // saveRecords(stats); } } At runtime it will have about 30 concurrent running threads each calling notify(key) about 100 times. Only one StatsHarvester is calling statsService.getStats() So i have many writers and only one reader. it would be nice to have accurate stats but i don't care if some records are lost on high concurrency. The reader should run every 5 Minutes or whatever is reasonable. Writing should be as fast as possible. Reading should be fast but if it locks for about 300ms every 5 minutes, its fine. I've read many docs (Java concurrency in practice, effective java and so on), but i have the strong feeling that i need your advice to get it right. I hope i stated my problem clear and short enough to get valuable help.

  Read the article

• My style/control template out my calendar's blackout dates.

  - by Chris

  Howdy, My C#/WPF project needs a calendar. We're going to be using it to pick a range of dates for appointment scheduling. I'm told the default calendar is too small to be used by some of our reps so I've been working on resizing it. <toolkit:Calendar Grid.Row="1" x:Name="DateWindowCalendar" BorderBrush="White" BorderThickness="0" Style="{StaticResource PopupCalendarStyle}" DisplayMode="Month" SelectionMode="SingleRange" DisplayDateStart="{Binding FirstDayOfMonth}" AutomationProperties.AutomationId="ToolkitCalendarId" VerticalAlignment="Top"> </toolkit:Calendar> And I've created this styling: <Style x:Key="PopupCalendarStyle" TargetType="toolkit:Calendar"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="toolkit:Calendar"> <StackPanel Margin="0" HorizontalAlignment="Center" x:Name="Root"> <toolkit:Calendar x:Name="Calendar" SelectedDate="{TemplateBinding SelectedDate}" DisplayDateStart="{TemplateBinding DisplayDateStart}" SelectionMode="{TemplateBinding SelectionMode}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" SelectedDatesChanged="Calendar_SelectedDatesChanged"> <toolkit:Calendar.CalendarDayButtonStyle> <Style> <Setter Property="Button.Height" Value="34"/> <Setter Property="Button.Width" Value="34" /> <Setter Property="Button.FontSize" Value="16" /> </Style> </toolkit:Calendar.CalendarDayButtonStyle> <toolkit:Calendar.CalendarButtonStyle> <Style> <Setter Property="Button.Height" Value="34"/> <Setter Property="Button.Width" Value="34"/> <Setter Property="Button.FontSize" Value="16"/> </Style> </toolkit:Calendar.CalendarButtonStyle> </toolkit:Calendar> </StackPanel> </ControlTemplate> </Setter.Value> </Setter> </Style> Everything is almost perfect. I specify my range, I can track the selected dates (granted using the SelectedDatesChanged event instead of the SelectedDates property. The problem is I also need to be able to set blackout dates (usually the period between first of the month and today although sometimes first of the month to a few days from now). Without the styling, this works: DateWindowCalendar.BlackoutDates.Add(new CalendarDateRange( new DateTime(DateTime.Now.Year, DateTime.Now.Month, 01), DateTime.Now)); But when I add the style, I don't get the black out displays being displayed and worse its possible to select the blackout dates. I'm not sure what I missed but I'm hoping someone has an easy answer so that I don't have to rebuild the entire widget. Any help is appreciated. Thanks, Chris

  Read the article

• Discovering a functional algorithm from a mutable one

  - by Garrett Rowe

  This isn't necessarily a Scala question, it's a design question that has to do with avoiding mutable state, functional thinking and that sort. It just happens that I'm using Scala. Given this set of requirements: Input comes from an essentially infinite stream of random numbers between 1 and 10 Final output is either SUCCEED or FAIL There can be multiple objects 'listening' to the stream at any particular time, and they can begin listening at different times so they all may have a different concept of the 'first' number; therefore listeners to the stream need to be decoupled from the stream itself. Pseudocode: if (first number == 1) SUCCEED else if (first number >= 9) FAIL else { first = first number rest = rest of stream for each (n in rest) { if (n == 1) FAIL else if (n == first) SUCCEED else continue } } Here is a possible mutable implementation: sealed trait Result case object Fail extends Result case object Succeed extends Result case object NoResult extends Result class StreamListener { private var target: Option[Int] = None def evaluate(n: Int): Result = target match { case None => if (n == 1) Succeed else if (n >= 9) Fail else { target = Some(n) NoResult } case Some(t) => if (n == t) Succeed else if (n == 1) Fail else NoResult } } This will work but smells to me. StreamListener.evaluate is not referentially transparent. And the use of the NoResult token just doesn't feel right. It does have the advantage though of being clear and easy to use/code. Besides there has to be a functional solution to this right? I've come up with 2 other possible options: Having evaluate return a (possibly new) StreamListener, but this means I would have to make Result a subtype of StreamListener which doesn't feel right. Letting evaluate take a Stream[Int] as a parameter and letting the StreamListener be in charge of consuming as much of the Stream as it needs to determine failure or success. The problem I see with this approach is that the class that registers the listeners should query each listener after each number is generated and take appropriate action immediately upon failure or success. With this approach, I don't see how that could happen since each listener is forcing evaluation of the Stream until it completes evaluation. There is no concept here of a single number generation. Is there any standard scala/fp idiom I'm overlooking here?

  Read the article

• How to customize android analog clock widget through configuration screen

  - by michJ

  I'm trying to develop my own analog clock widget on the home screen. It's based on the stock ICS analog clock widget, but when added to the homescreen, my widget opens a configuration screen first. On this screen you can choose the color you want the clock to be (through a colorpicker dialog). You also see a preview of the clock in the chosen color on this screen. (See picture). My problem is changing the color of the widget on the home screen to the chosen color (when you hit the apply button). I have three .png files that I use for the dial, hour hand and minute hand. I color them using this code in my widgetconfig class: Drawable dial = getResources().getDrawable(R.drawable.clockbackground); dial.setColorFilter(color, PorterDuff.Mode.MULTIPLY); //hour Drawable hour = getResources().getDrawable(R.drawable.hourhand); hour.setColorFilter(color, PorterDuff.Mode.MULTIPLY); //minute Drawable min = getResources().getDrawable(R.drawable.minutehand); min.setColorFilter(color, PorterDuff.Mode.MULTIPLY); // clock AnalogClock clockpreview = (AnalogClock) findViewById(R.id.ACconfig); clockpreview.setBackgroundDrawable(dial); This works fine because I can find the AnalogClock since it's in the layout xml file of the configuration screen, which I set in the OnCreate() through setContentView(). The problem is that for the clock widget on my screen I have to use RemoteViews. So I tried setting the new background of the clock widget through RemoteViews. But RemoteViews seems too limited to do this. I need something like setTextViewText() but then for the background of my analog clock widget, like for example: RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.clockwidget); views.setAnalogClockBackgroundDrawable(dial); The clock widget background seems sort of unchangeable. How can I recolor my clockwidget on homescreen in widgetconfig class? There must be a way because it seems so easy to do at first... My project consists of the widget config class and clockwidget class, widgetconfig.xml, clockwidget.xml, and widget_info.xml (for appwidgetprovider).

  Read the article

• With NHibernate, how can I create an INHibernateProxy?

  - by Eric

  After lots of reading about serialization, I've decided to try to create DTOs. After more reading, I decided to use AutoMapper. What I would like to do is transform the parent (easy enough) and transform the entity properties if they've been initialized, which I've done with ValueResolvers like below (I may try to make it generic once I get it fully working). This part works. public class OrderItemResolver : ValueResolver<Order, OrderItem> { protected override OrderItem ResolveCore(Order source) { // could also use NHibernateUtil.IsInitialized(source.OrderItem) if (source.OrderItem is NHibernate.Proxy.INHibernateProxy) return null; else return source.OrderItem; } } } When I transform the DTO back to an entity, for the entities that weren't initialized, I want to create a proxy so that if the entity wants to access it, it can. However, I can't figure out how to create a proxy. I'm using Castle if that's relevant. I've tried a bunch of things with no luck. The below code is a mess, mainly because I've been trying things at random without knowing what I should be doing. Anybody have any suggestions? public class OrderItemDTOResolver : ValueResolver<OrderDTO, OrderItem> { protected override OrderItem ResolveCore(OrderDTO source) { if (source.OrderItem == null) { //OrderItem OrderItem = new ProxyGenerator().CreateClassProxy<OrderItem>(); // Castle.Core.Interceptor. //OrderItem OrderItem = new ProxyGenerator().CreateClassProxy<OrderItem>(); //OrderItem.Id = source.OrderItemId; //OrderItem OrderItem = new OrderItem(); //var proxy = new OrderItem() as INHibernateProxy; //var proxy = OrderItem as INHibernateProxy; //return (OrderItem)proxy.HibernateLazyInitializer //ILazyInitializer proxy = new LazyInitializer("OrderItem", OrderItem, source.OrderItemId, null, null, null, null); //return (OrderItem)proxy; //return (OrderItem)proxy.HibernateLazyInitializer.GetImplementation(); //return OrderItem; IProxyTargetAccessor proxy = new Castle.Core.Interceptor. var initializer = new LazyInitializer("OrderItem", typeof(OrderItem), source.OrderItemId, null, null, null, null); //var proxyFactory = new SerializableProxyFactory{Interfaces = Interfaces, TargetSource = initializer, ProxyTargetType = IsClassProxy}; //proxyFactory.AddAdvice(initializer); //object proxyInstance = proxyFactory.GetProxy(); //return (INHibernateProxy) proxyInstance; return null; //OrderItem.Id = source.OrderItemId; //return OrderItem; } else return OrderItemDTO.Unmap(source.OrderItem); } } Thanks, Eric

  Read the article

• Information Gain and Entropy

  - by dhorn

  I recently read this question regarding information gain and entropy. I think I have a semi-decent grasp on the main idea, but I'm curious as what to do with situations such as follows: If we have a bag of 7 coins, 1 of which is heavier than the others, and 1 of which is lighter than the others, and we know the heavier coin + the lighter coin is the same as 2 normal coins, what is the information gain associated with picking two random coins and weighing them against each other? Our goal here is to identify the two odd coins. I've been thinking this problem over for a while, and can't frame it correctly in a decision tree, or any other way for that matter. Any help? EDIT: I understand the formula for entropy and the formula for information gain. What I don't understand is how to frame this problem in a decision tree format. EDIT 2: Here is where I'm at so far: Assuming we pick two coins and they both end up weighing the same, we can assume our new chances of picking H+L come out to 1/5 * 1/4 = 1/20 , easy enough. Assuming we pick two coins and the left side is heavier. There are three different cases where this can occur: HM: Which gives us 1/2 chance of picking H and a 1/4 chance of picking L: 1/8 HL: 1/2 chance of picking high, 1/1 chance of picking low: 1/1 ML: 1/2 chance of picking low, 1/4 chance of picking high: 1/8 However, the odds of us picking HM are 1/7 * 5/6 which is 5/42 The odds of us picking HL are 1/7 * 1/6 which is 1/42 And the odds of us picking ML are 1/7 * 5/6 which is 5/42 If we weight the overall probabilities with these odds, we are given: (1/8) * (5/42) + (1/1) * (1/42) + (1/8) * (5/42) = 3/56. The same holds true for option B. option A = 3/56 option B = 3/56 option C = 1/20 However, option C should be weighted heavier because there is a 5/7 * 4/6 chance to pick two mediums. So I'm assuming from here I weight THOSE odds. I am pretty sure I've messed up somewhere along the way, but I think I'm on the right path! EDIT 3: More stuff. Assuming the scale is unbalanced, the odds are (10/11) that only one of the coins is the H or L coin, and (1/11) that both coins are H/L Therefore we can conclude: (10 / 11) * (1/2 * 1/5) and (1 / 11) * (1/2) EDIT 4: Going to go ahead and say that it is a total 4/42 increase.

  Read the article

• Collision point of 2 curves in a 3d-room

  - by Frank

  Hello, i am programming a small game for quite some time. We started coding a small FPS-Shooter inside of a project at school to get a bit experience using directX. I dont know why, but i couldnt stop the project and started programming at home aswell. At the moment i am trying to create some small AI. Of cause thats definatlly not easy, but thats my personal goal anyways. The topic could prolly fill multiple books hehe. I've got the walking part of my bots done so far. They walk along a scriped path. I am not working on the "aiming" of the bots. While programming that i hit on some math problem i couldnt solve yet. I hope of your input on this to help me get further. Concepts, ideas and everything else are highly appreciated. Problem: Calculate the position (D3DXVECTOR3) where the curve of the projectile (depends on gravity, speed), hit the curved of the enemys walking path (depends on speed). We assume that the enemy walks in a constant line. Known variables: float projectilSpeed = 2000 m/s //speed of the projectile per second float gravitation = 9.81 m/s^2 //of cause the gravity lol D3DXVECTOR3 targetPosition //position of the target stored in a vector (x,y,z) D3DXVECTOR3 projectilePosition //position of the projectile D3DXVECTOR3 targetSpeed //stores the change of the targets position in the last second Variabledefinition ProjectilePosition at time of collision = ProjectilePos_t TargetPosition at time of collision = TargetPos_t ProjectilePosition at time 0, now = ProjectilePos_0 TargetPosition at time 0, now = TargetPos_0 Time to impact = t Aim-angle = theta My try: Found a formular to calculate "drop" (Drop of the projectile based on the gravity) on Wikipedia: float drop = 0.5f * gravity * t * t The speed of the projectile has a horizontal and a vertical part.. Found a formular for that on wikipedia aswell: ProjectilVelocity.x = projectilSpeed * cos(theta) ProjectilVelocity.y = projectilSpeed * sin(theta) So i would assume this is true for the projectile curve: ProjectilePos_t.x = ProjectilePos_0.x + ProjectileSpeed * t ProjectilePos_t.y = ProjectilePos_0.y + ProjectileSpeed * t + 0.5f * gravity * t * t ProjectilePos_t.z = ProjectilePos_0.z + ProjectileSpeed * t The target walk with a constant speed, so we can determine his curve by this: TargetPos_t = TargetPos_0 + TargetSpeed * D3DXVECTOR3(t, t, t) Now i dont know how to continue. I have to solve it somehow to get a hold on the time to impact somehow. As a basic formular i could use: float time = distanz / projectileSpeed But that wouldnt be truly correct as it would assume a linear "Trajectory". We just find this behaivor when using a rocket. I hope i was able to explain the problem as much as possible. If there are questions left, feel free to ask me! Greets from germany, Frank

  Read the article

• SQLite bulk insert on iPhone not working

  - by App_beginner

  Hi. I have been struggling with this seeminly easy problem for 48 hours, and I am no closer to a solution. So I was hoping that someone might be able to help me. I am building a app, that use a combination of a local (SQLite) database and an online database (PHP/MYSQL). The app is nearly finished. Checked for leaks and work like a charm. However the very last part is the part I have struggled with. On launch, I want the app to check for changes to the online databse, and if there is. I want it to download and parse a xml file containing the changes. Everything is working fine this far. But when I try to bulk insert my parsed data to my database, the app crashes, giving a NSInternalInconsistency error. Due to the database returning SQLITE_MISUSE. I have done a lot of googling, but am still unable to solve my problem. So I am putting the code here, hoping that someone can help me fix this. And I know that I should have used core data for this. But this is the very last part I am struggling with, and I am very reluctant to changing my entire code now. Core data will have to come in the update. Here is the error I recieve: Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Error while inserting data. 'library routine called out of sequence'' Here is my code: -(void)UpdateDatabase:(const char *)_query NewValues:(NSMutableArray *)_odb dbn:(NSString *)_dbn dbp:(NSString *)_dbp { sqlite3 *database; NSMutableArray *NewValues = _odb; int i; const char *query = _query; sqlite3_stmt *addStmt; for (i = 1; i < [NewValues count]; i++) { if(sqlite3_prepare_v2(database, query, -1, &addStmt, NULL) == SQLITE_OK) { sqlite3_bind_text(addStmt, 1, [[[NewValues objectAtIndex:i] name] UTF8String], -1, SQLITE_TRANSIENT); sqlite3_bind_text(addStmt, 2, [[[NewValues objectAtIndex:i] city]UTF8String], -1, SQLITE_TRANSIENT); sqlite3_bind_double(addStmt, 3, [[[NewValues objectAtIndex:i] lat] doubleValue]); sqlite3_bind_int(addStmt, 4, [[[NewValues objectAtIndex:i] long] doubleValue]); sqlite3_bind_int(addStmt, 5, [[[NewValues objectAtIndex:i] code] intValue]); } if(SQLITE_DONE != sqlite3_step(addStmt)) { NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(database)); } //Reset the add statement. sqlite3_reset(addStmt); } }

  Read the article

• c++ class member functions selected by traits

  - by Jive Dadson

  I am reluctant to say I can't figure this out, but I can't figure this out. I've googled and searched stackoverflow, and come up empty. The abstract, and possibly overly vague form of the question is, how can I use the traits-pattern to instantiate non-virtual member functions? The question came up while modernizing a set of multivariate function optimizers that I wrote more than 10 years ago. The optimizers all operate by selecting a straight-line path through the parameter space away from the current best point (the "update"), then finding a better point on that line (the "line search"), then testing for the "done" condition, and if not done, iterating. There are different methods for doing the update, the line-search, and conceivably for the done test, and other things. Mix and match. Different update formulae require different state-variable data. For example, the LMQN update requires a vector, and the BFGS update requires a matrix. If evaluating gradients is cheap, the line-search should do so. If not, it should use function evaluations only. Some methods require more accurate line-searches than others. Those are just some examples. The original version instatiates several of the combinations by means of virtual functions. Some traits are selected by setting mode bits. Yuck. It would be trivial to define the traits with #define's and the member functions with #ifdef's and macros. But that's so twenty years ago. It bugs me that I cannot figure out a whiz-bang modern way. If there were only one trait that varied, I could use the curiously recurring template pattern. But I see no way to extend that to arbitrary combinations of traits. I tried doing it using boost::enable_if, etc.. The specialized state info was easy. I managed to get the functions done, but only by resorting to non-friend external functions that have the this-pointer as a parameter. I never even figured out how to make the functions friends, much less member functions. Perhaps tag-dispatch is the key. I haven't gotten very deeply into that. Surely it's possible, right? If so, what is best practice?

  Read the article

< Previous Page | 490 491 492 493 494 495 496 497 498 499 500 501  | Next Page >