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  • What Language Feature Can You Just Not Live Without?

    - by akdom
    I always miss python's built-in doc strings when working in other languages. I know this may seem odd, but it allows me to cut down significantly on excess comments while still providing a clean description of my code and any interfaces therein. What Language Feature Can You Just Not Live Without? If someone were building a new language and they asked you what one feature they absolutely must include, what would it be? This is getting kind of long, so I figured I'd do my best to summarize: Paraphrased to be language agnostic. If you know of a language which uses something mentioned, please at it in the parenthesis to the right of the feature. And if you have a better format for this list, by all means try it out (if it doesn't seem to work, I'll just roll back). Regular Expressions ~ torial (Perl) Garbage Collection ~ SaaS Developer (Python, Perl, Ruby, Java, .NET) Anonymous Functions ~ Vinko Vrsalovic (Lisp, Python) Arithmetic Operators ~ Jeremy Ross (Python, Perl, Ruby, Java, C#, Visual Basic, C, C++, Pascal, Smalltalk, etc.) Exception Handling ~ torial (Python, Java, .NET) Pass By Reference ~ Chris (Python) Unified String Format WalloWizard (C#) Generics ~ torial (Python, Java, C#) Integrated Query Equivalent to LINQ ~ Vyrotek (C#) Namespacing ~ Garry Shutler () Short Circuit Logic ~ Adam Bellaire ()

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  • some help required while working on java and cigwin together .

    - by Hippo
    Hello .. I am new to java and also cygwin . I do not have in detailed knowledge of both . I need some help.. I simple steps i will try to explain my problem. 1) I am working on tinyOS . its open source OS , used for wireless sensor networks. It provides java libraries to work on communication (PC to sensor) 2) I am working on windows xp environment through cigwin. 3) I am developing an application . THis application requires one java interface called "Serial Forwarder" , which is readily available in libraries provided. Previously i used to start this interface manually (by entering command *"java net.tinyos.sf.SerialForwarder ")*and then my application which uses this interface. But now i want to make my application independent . User need know about this background cygwin commands . 4) So in my java application i used "Runtime.getRuntime().exec( "java net.tinyos.sf.SerialForwarder)" . 5) This i neither giving any error nor starting the interface. Am I going on right way ? When i am using runtime execute command , how can i make sure that this command is called through cigwin interface ? Also .. if i want to write .bat file .. i which i can give commands which will be executed .. how can i make sure that those commands are given through cigwin .. and not through cmd.exe .. Please help . me .

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  • making java SingleFrameApplication to appear second

    - by Karel Bílek
    Sorry if this question will sound too chaotic, feel free to edit it. I have an application made entirely in netbeans, which uses SingleFrameApplication and auto-generated the GUI code, named "MyApp", and FrameView, named "MyView". Now, the MyApp somehow has the main() function, but the MyView has all the graphic elements.. I don't entirely understand how that happens, so used it as black box (it somehow created the window, I didn't have to care why). But now, I need the window to be only a window, opened by another JFrame. I don't know, how to accomplish that. MyApp, which is extending SingleFrameApplication, have these methods: public class MyApp extends SingleFrameApplication { @Override protected void startup() { show(new MyView(this)); } @Override protected void configureWindow(java.awt.Window root) { } public static MyApp getApplication() { return Application.getInstance(MyApp.class); } public static void main(String[] args) { launch(MyApp.class, args); } } MyView has these methods: public class MyView extends FrameView { public MyView(SingleFrameApplication app) { super(app); initComponents(); } private void initComponents() { //all the GUI stuff is somehow defined here } } Now, I have no clue how the two classes work, I just want this window, defined in MyView, to appear after another window, "ordinary" JFrame. How can I call this MyApp/MyView?

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  • Alternate cause of BadImageFormatException in .NET Assembly?

    - by Phillip Knauss
    I'm working on a .NET 3.5 console application in C# which uses a VC++ unmanaged DLL. It ran without a problem when I worked on it a few weeks ago, but I'm coming back to it today and am now getting a BadImageFormatException ("An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)). My development workstation is running 64bit Windows 7, and I do a fair amount of work with unmanaged code, so I immediately checked that the .NET assembly and the VC++ library both had x86 targets. They did. Just to be sure, I cleaned and rebuilt the VC++ library and the .NET assembly, to no avail. Neither system is doing anything particularly unusual. The VC++ library loads a binary data file and does some mathematical processing on its contents. The .NET assembly has the DllImports for the library and some code to wire it up. This all worked a few weeks ago. So now I'm left wondering if there's some other cause of BadImageFormatException that's less common than an x86/x64 conflict that I might be running into. Thanks.

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  • Does anyone know of a good Commercial WPF Web Browser Control?

    - by VoidDweller
    I have an MDI WPF app that I need to add web content too. At first, great it looks like I have 2 options built into the framework the Frame control and the WebBrowser control. Given that this is an MDI app it doesn't take long to discover that neither of these will work. The WebBrowser control wraps up the IE WebBrowser ActiveX Control which uses the Win32 graphics pipeline. The "Airspace" issue pretty much sums this up as "Sorry, the layouts will not play nice together". Yes, I have thought about taking snapshots of the web content rendering these and mapping the mouse and keyboard events back to the browser control, but I can't afford the performance penalty and I really don't have time to write and thoroughly test it. I have looked for third party controls, but so far I have only found Chris Cavanagh's WPF Chromium Web Browser control. Which wraps up Awesomium 1.5. Together these are very cool, they play nice with the WPF layouts. But they do not meet my performance requirements. They are VERY HEAVY on memory consumption and not to friendly with CPU usage either. Not to mention still quite buggy. I'll elaborate if you are interested. So, do any of you know of a stable performant WPF web browser control? Thanks.

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  • SQL Server Search Proper Names Full Text Index vs LIKE + SOUNDEX

    - by Matthew Talbert
    I have a database of names of people that has (currently) 35 million rows. I need to know what is the best method for quickly searching these names. The current system (not designed by me), simply has the first and last name columns indexed and uses "LIKE" queries with the additional option of using SOUNDEX (though I'm not sure this is actually used much). Performance has always been a problem with this system, and so currently the searches are limited to 200 results (which still takes too long to run). So, I have a few questions: Does full text index work well for proper names? If so, what is the best way to query proper names? (CONTAINS, FREETEXT, etc) Is there some other system (like Lucene.net) that would be better? Just for reference, I'm using Fluent NHibernate for data access, so methods that work will with that will be preferred. I'm using SQL Server 2008 currently. EDIT I want to add that I'm very interested in solutions that will deal with things like commonly misspelled names, eg 'smythe', 'smith', as well as first names, eg 'tomas', 'thomas'. Query Plan |--Parallelism(Gather Streams) |--Nested Loops(Inner Join, OUTER REFERENCES:([testdb].[dbo].[Test].[Id], [Expr1004]) OPTIMIZED WITH UNORDERED PREFETCH) |--Hash Match(Inner Join, HASH:([testdb].[dbo].[Test].[Id])=([testdb].[dbo].[Test].[Id])) | |--Bitmap(HASH:([testdb].[dbo].[Test].[Id]), DEFINE:([Bitmap1003])) | | |--Parallelism(Repartition Streams, Hash Partitioning, PARTITION COLUMNS:([testdb].[dbo].[Test].[Id])) | | |--Index Seek(OBJECT:([testdb].[dbo].[Test].[IX_Test_LastName]), SEEK:([testdb].[dbo].[Test].[LastName] >= 'WHITDþ' AND [testdb].[dbo].[Test].[LastName] < 'WHITF'), WHERE:([testdb].[dbo].[Test].[LastName] like 'WHITE%') ORDERED FORWARD) | |--Parallelism(Repartition Streams, Hash Partitioning, PARTITION COLUMNS:([testdb].[dbo].[Test].[Id])) | |--Index Seek(OBJECT:([testdb].[dbo].[Test].[IX_Test_FirstName]), SEEK:([testdb].[dbo].[Test].[FirstName] >= 'THOMARþ' AND [testdb].[dbo].[Test].[FirstName] < 'THOMAT'), WHERE:([testdb].[dbo].[Test].[FirstName] like 'THOMAS%' AND PROBE([Bitmap1003],[testdb].[dbo].[Test].[Id],N'[IN ROW]')) ORDERED FORWARD) |--Clustered Index Seek(OBJECT:([testdb].[dbo].[Test].[PK__TEST__3214EC073B95D2F1]), SEEK:([testdb].[dbo].[Test].[Id]=[testdb].[dbo].[Test].[Id]) LOOKUP ORDERED FORWARD) SQL for above: SELECT * FROM testdb.dbo.Test WHERE LastName LIKE 'WHITE%' AND FirstName LIKE 'THOMAS%' Based on advice from Mitch, I created an index like this: CREATE INDEX IX_Test_Name_DOB ON Test (LastName ASC, FirstName ASC, BirthDate ASC) INCLUDE (and here I list the other columns) My searches are now incredibly fast for my typical search (last, first, and birth date).

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  • PHP Streaming CSV always adds UTF-8 BOM

    - by Mustafa Ashurex
    The following code gets a 'report line' as an array and uses fputcsv to tranform it into CSV. Everything is working great except for the fact that regardless of the charset I use, it is putting a UTF-8 bom at the beginning of the file. This is exceptionally annoying because A) I am specifying iso and B) We have lots of users using tools that show the UTF-8 bom as characters of garbage. I have even tried writing the results to a string, stripping the UTF-8 BOM and then echo'ing it out and still get it. Is it possible that the issue resides with Apache? If I change the fopen to a local file it writes it just fine without the UTF-8 BOM. header("Content-type: text/csv; charset=iso-8859-1"); header("Cache-Control: no-store, no-cache"); header("Content-Disposition: attachment; filename=\"report.csv\""); $outstream = fopen("php://output",'w'); for($i = 0; $i < $report-rowCount; $i++) { fputcsv($outstream, $report-getTaxMatrixLineValues($i), ',', '"'); } fclose($outstream); exit;

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  • NSMutableURLRequest wont turn on 3G

    - by Kyle
    I won't bother posting any code because my code works fine when I launch Safari or something that turns on the 3G connection first. When I put it Airport mode, then put back OFF, I will get the behavior of a connection error saying No internet connection with NSMutableURLRequest. I've personally mailed apple about how the Ant gets turned on and off, and they said anything that uses their base CFSocketStream object will turn on the Ant, and I quote: "such as NSURLRequest".. BSD Sockets do not, just so everyone knows.. However, I assumed NSMutableURLRequest would fall into the category of 'Does', but it seems like it doesnt. It never succeeds for me when I cycle Airport or have the phone idle for a long time. It will ALWAYS succeed when I open any other network app first to turn the Ant on. Shall I be forced to do a dummy NSURLRequest call to turn this on; or has anyone been able to get this class working just fine? Remember this is just an implementation of NSMutableURLRequest to upload a file Async, and no other Network operations are performed anywhere; no ads, no version checks, no nothing.

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  • Migration of .NET COM object to 64 bit.

    - by Victor Ronin
    Hi, We have C++ application which uses several COM object. COM object are .NET based (using COM Interop). I need to migrate application to 64 bit. I specifically need C++ application to be 64 bit. I don't want to recompile all of .NET com object to 64 bit and deliver two sets of DLL's (32 bit and 64 bit). I was investigating and found that I can load 32 bit COM Dll's in 32 bit surrogate process using (DllSurrogate in registry). I know how to do that, but it means that all COM objects will become out of process. In the C++ I had the code: CoCreateInstance(CLSID_SomeClass, NULL, CLSCTX_INPROC_SERVER, IID_SomeInterface, (void**)&pobj); It worked fine, but as soon as I switch to CLSCTX_LOCAL_SERVER (and add registry keys for DllSurrogate), it can't find interfaces (error 0x80004002). I checked registry and found out that when .NET COM DLL is registered, it adds ClsID registry keys, but doesn't add Interface and TypeLib registry key. The question is, how to create these registry keys for .NET COM? Regards, Victor

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  • Implementing parts of rfc4226 (HOTP) in mysql

    - by Moose Morals
    Like the title says, I'm trying to implement the programmatic parts of RFC4226 "HOTP: An HMAC-Based One-Time Password Algorithm" in SQL. I think I've got a version that works (in that for a small test sample, it produces the same result as the Java version in the code), but it contains a nested pair of hex(unhex()) calls, which I feel can be done better. I am constrained by a) needing to do this algorithm, and b) needing to do it in mysql, otherwise I'm happy to look at other ways of doing this. What I've got so far: -- From the inside out... -- Concatinate the users secret, and the number of time its been used -- find the SHA1 hash of that string -- Turn a 40 byte hex encoding into a 20 byte binary string -- keep the first 4 bytes -- turn those back into a hex represnetation -- convert that into an integer -- Throw away the most-significant bit (solves signed/unsigned problems) -- Truncate to 6 digits -- store into otp -- from the otpsecrets table select (conv(hex(substr(unhex(sha1(concat(secret, uses))), 1, 4)), 16, 10) & 0x7fffffff) % 1000000 into otp from otpsecrets; Is there a better (more efficient) way of doing this?

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  • Dismissing UIImagePickerController from UITabBarController

    - by Dave
    I have a tab bar application whereby one tab uses a navigation controller to move through a series of views. On the final view, there is a button to add a photo, which presents a UIImagePickerController. So far, so good - however when I finish picking the image, or cancel the operation, the previous view is loaded, but without the tab bar. I'm sure I'm missing something elementary, but any suggestions on how to properly release the UIImagePickerController would be much appreciated. The code is as follows: ImagePickerViewController *aController = [[ImagePickerViewController alloc]; initWithNibName:@"ImagePickerViewController" bundle:[NSBundle mainBundle]]; [self presentModalViewController:aController animated:YES]; [aController release]; //viewDidLoad self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease]; imagePickerController = [[UIImagePickerController alloc] init]; imagePickerController.delegate = self; if([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera]){ imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera; } else { imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; } [window addSubview:imagePickerController.view]; //ImagePickerViewController imagePickerControllerDidCancel - FinalViewController is the last view in the stack controlled by a navigation controller which contains the button to present the UIImagePickerController [picker dismissModalViewControllerAnimated:YES]; FinalViewController *aController = [[FinalViewController alloc initWithNibName:@"FinalViewController" bundle:[NSBundle mainBundle]]; [picker presentModalViewController:aController animated:YES]; [aController release];

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  • priority queue with limited space: looking for a good algorithm

    - by SigTerm
    This is not a homework. I'm using a small "priority queue" (implemented as array at the moment) for storing last N items with smallest value. This is a bit slow - O(N) item insertion time. Current implementation keeps track of largest item in array and discards any items that wouldn't fit into array, but I still would like to reduce number of operations further. looking for a priority queue algorithm that matches following requirements: queue can be implemented as array, which has fixed size and _cannot_ grow. Dynamic memory allocation during any queue operation is strictly forbidden. Anything that doesn't fit into array is discarded, but queue keeps all smallest elements ever encountered. O(log(N)) insertion time (i.e. adding element into queue should take up to O(log(N))). (optional) O(1) access for *largest* item in queue (queue stores *smallest* items, so the largest item will be discarded first and I'll need them to reduce number of operations) Easy to implement/understand. Ideally - something similar to binary search - once you understand it, you remember it forever. Elements need not to be sorted in any way. I just need to keep N smallest value ever encountered. When I'll need them, I'll access all of them at once. So technically it doesn't have to be a queue, I just need N last smallest values to be stored. I initially thought about using binary heaps (they can be easily implemented via arrays), but apparently they don't behave well when array can't grow anymore. Linked lists and arrays will require extra time for moving things around. stl priority queue grows and uses dynamic allocation (I may be wrong about it, though). So, any other ideas?

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  • Backwards compatibility when using Core Data

    - by Alex
    Could anybody shed some light as to why is my app crashing with the following error on iPhone OS 2.2.1 dyld: Symbol not found: _OBJC_CLASS_$_NSPredicate Referenced from: /var/mobile/Applications/456F243F-468A-4969-9BB7-A4DF993AE89C/AppName.app/AppName Expected in: /System/Library/Frameworks/Foundation.framework/Foundation I have weak linked CoreData.framework, and have the Base SDK set to 3.0 and Deployment Target set to SDK 2.2 The app already uses other 3.0 features when available and I did not have any problems with those. But apparently the backward-compatibility methods used for other features do not work with Core Data. The app crashes before app delegate's applicationDidFinishLaunching gets called. Here's the debugger log: [Session started at 2010-05-25 20:17:03 -0400.] GNU gdb 6.3.50-20050815 (Apple version gdb-1119) (Thu May 14 05:35:37 UTC 2009) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "--host=i386-apple-darwin --target=arm-apple-darwin".tty /dev/ttys001 Loading program into debugger… sharedlibrary apply-load-rules all warning: Unable to read symbols from "MessageUI" (not yet mapped into memory). warning: Unable to read symbols from "CoreData" (not yet mapped into memory). Program loaded. target remote-mobile /tmp/.XcodeGDBRemote-12038-42 Switching to remote-macosx protocol mem 0x1000 0x3fffffff cache mem 0x40000000 0xffffffff none mem 0x00000000 0x0fff none run Running… [Switching to thread 10755] [Switching to thread 10755] Re-enabling shared library breakpoint 1 Re-enabling shared library breakpoint 2 Re-enabling shared library breakpoint 3 Re-enabling shared library breakpoint 4 Re-enabling shared library breakpoint 5 (gdb) continue warning: Unable to read symbols for ""/Users/alex/iPhone Projects/AppName/build/Debug-iphoneos"/AppName.app/AppName" (file not found). dyld: Symbol not found: _OBJC_CLASS_$_NSPredicate Referenced from: /var/mobile/Applications/456F243F-468A-4969-9BB7-A4DF993AE89C/AppName.app/AppName Expected in: /System/Library/Frameworks/Foundation.framework/Foundation (gdb)

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  • PHP (A few questions) OO, refactoring, eclipse

    - by jax
    I am using PHP in eclipse. It works ok, I can connect to my remote site, there is colour coding of code elements and some code hints. I realise this may be too long to answer all questions, if you have a good answer for one part, answering just that is ok. Firstly General Coding I have found that it is easy to loose track of included files and their variables. For example if there was a database $cursor it is difficult to remember or even know that it was declared in the included file (this becomes much worse the more files you include). How are people dealing with this? How are people documenting their code - in particular the required GET and POST data? Secondly OO Development: Should I be going full OO in my development. Currently I have a functions library which I can include and have separated each "task" into a separate file. It is a bit nasty but it works. If I go OO how do I structure the directories in PHP, java uses packages - what about php? How should I name my files, should I use all lower case with _ for spaces "hello_world.php"? Should I name classes with Uppercase like Java "HelloWorld.php"? Is there a different naming convention for Classes and regular function files? Thirdly Refactoring I must say this is a real pain. If I change the name of a variable in one place I have to go through whole document and each file that included this file and change the name their too. Of course, errors everywhere is what results. How are people dealing with this problem? In Java if you change the name in one place it changes everywhere. Are there any plugins to improve php refactoring? I am using the official PHP version of Eclipse from their website. thanks

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  • NMock2.0 - how to stub a non interface call?

    - by dferraro
    Hello, I have a class API which has full code coverage and uses DI to mock out all the logic in the main class function (Job.Run) which does all the work. I found a bug in production where we werent doing some validation on one of the data input fields. So, I added a stub function called ValidateFoo()... Wrote a unit test against this function to Expect a JobFailedException, ran the test - it failed obviously because that function was empty. I added the validation logic, and now the test passes. Great, now we know the validation works. Problem is - how do I write the test to make sure that ValidateFoo() is actually called inside Job.Run()? ValidateFoo() is a private method of the Job class - so it's not an interface... Is there anyway to do this with NMock2.0? I know TypeMock supports fakes of non interface types. But changing mock libs right now is not an option. At this point if NMock can't support it, I will simply just add the ValidateFoo() call to the Run() method and test things manually - which obviously I'd prefer not to do considering my Job.Run() method has 100% coverage right now. Any Advice? Thanks very much it is appreciated. EDIT: the other option I have in mind is to just create an integration test for my Job.Run functionality (injecting to it true implementations of the composite objects instead of mocks). I will give it a bad input value for that field and then validate that the job failed. This works and covers my test - but it's not really a unit test but instead an integration test that tests one unit of functionality.... hmm.. EDIT2: IS there any way to do tihs? Anyone have ideas? Maybe TypeMock - or a better design?

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  • How to not pass around the container when using IoC in Winforms

    - by L2Type
    I'm new to the world of IoC and having a problem with implementing it in a Winforms application. I have an extremely basic application Winform application that uses MVC, it is one controller that does all the work and a working dialog (obviously with a controller). So I load all my classes in to my IoC container in program.cs and create the main form controller using the container. But this is where I am having problems, I only want to create the working dialog controller when it's used and inside a using statement. At first I passed in the container but I've read this is bad practice and more over the container is a static and I want to unit test this class. So how do you create classes in a unit test friendly way without passing in the container, I was considering the abstract factory pattern but that alone would solve my problem without using the IoC. I'm not using any famous framework, I borrowed a basic one from this blog post http://www.kenegozi.com/Blog/2008/01/17/its-my-turn-to-build-an-ioc-container-in-15-minutes-and-33-lines.aspx How do I do this with IoC? Is this the wrong use for IoC?

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  • Table borders don't display properly when converted from HTML page into MS Word 2003

    - by Daria
    Hello everyone, I've got a bit of a complicated set up. I specialise in XSLT which I write for 3rd party system. All CSS looks fine in the browser. Now that system provides a button that converts my generated HTML into MS Word 2003. However, table borders don't convert as they appear in a Browser. There are lots of tables and they have different borders setup. For example there is one that uses only outside border and no borders inside it. When converting to MS Word, a table appears with ALL the borders in between cells. Which I don't want. I've tried search the Internet, but didn't come across anything useful. Maybe there are tips or tricks on how to set up tables borders so it's understood properly by MS Word. The third party said the following: "The system just passes the HTML created through the converter it finds in the installed version of Word". I would really appreciate any tips and help! Dasha

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  • Permission denied (maybe missing INTERNET permission) when calling web service

    - by Maxim
    I'm trying to use .net SOAP web service with ksoap2 lib. Example from http://www.vimeo.com/9633556 shows how to do it correct. Below the code from that example. everything shoud work ok, but when I try to do a call inself (httpTransport.call) I get "Permission denied (maybe missing INTERNET permission)" exception. Moreover, I don't see in the Application info window among permissions the internet permission alert. Tried this on emulator and Google phone. Will be very appreciated if somebody could help with it. Thanks. public void CelsiusToFahrenheit() { String SOAP_ACTION = "http://tempuri.org/CelsiusToFahrenheit"; String METHOD_NAME = "CelsiusToFahrenheit"; String NAMESPACE = "http://tempuri.org/"; String URL = "http://www.w3schools.com/webservices/tempconvert.asmx"; SoapObject Request = new SoapObject(NAMESPACE, METHOD_NAME); Request.addProperty("Celsius", "32"); SoapSerializationEnvelope soapEnvelope = new SoapSerializationEnvelope(SoapEnvelope.VER11); soapEnvelope.dotNet = true; soapEnvelope.setOutputSoapObject(Request); AndroidHttpTransport httpTransport = new AndroidHttpTransport(URL); try { httpTransport.call(SOAP_ACTION, soapEnvelope); SoapPrimitive resultString = (SoapPrimitive)soapEnvelope.getResponse(); res = resultString.toString(); } catch (Exception e) { e.printStackTrace(); } } AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest> <application> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> <user-permission android:name="android.permission.INTERNET"></user-permission> <uses-sdk android:minSdkVersion="4" />

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  • Is it possible that a single-threaded program is executed simultaneously on more than one CPU core?

    - by Wolfgang Plaschg
    When I run a single-threaded program that i have written on my quad core Intel i can see in the Windows Task Manager that actually all four cores of my CPU are more or less active. One core is more active than the other three, but there is also activity on those. There's no other program (besided the OS kernel of course) running that would be plausible for that activitiy. And when I close my program all activity an all cores drops down to nearly zero. All is left is a little "noise" on the cores, so I'm pretty sure all the visible activity comes directly or indirectly (like invoking system routines) from my program. Is it possible that the OS or the cores themselves try to balance some code or execution on all four cores, even it's not a multithreaded program? Do you have any links that documents this technique? Some infos to the program: It's a console app written in Qt, the Task Manager states that only one thread is running. Maybe Qt uses threads, but I don't use signals or slots, nor any GUI. Link to Task Manager screenshot: http://img97.imageshack.us/img97/6403/taskmanager.png This question is language agnostic and not tied to Qt/C++, i just want to know if Windows or Intel do to balance also single-threaded code on all cores. If they do, how does this technique work? All I can think of is, that kernel routines like reading from disk etc. is scheduled on all cores, but this won't improve performance significantly since the code still has to run synchronous to the kernel api calls. EDIT Do you know any tools to do a better analysis of single and/or multi-threaded programs than the poor Windows Task Manager?

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  • Efficient data importing?

    - by Kevin
    We work with a lot of real estate, and while rearchitecting how the data is imported, I came across an interesting issue. Firstly, the way our system works (loosely speaking) is we run a Coldfusion process once a day that retrieves data provided from an IDX vendor via FTP. They push the data to us. Whatever they send us is what we get. Over the years, this has proven to be rather unstable. I am rearchitecting it with PHP on the RETS standard, which uses SOAP methods of retrieving data, which is already proven to be much better than what we had. When it comes to 'updating' existing data, my initial thought was to query only for data that was updated. There is a field for 'Modified' that tells you when a listing was last updated, and the code I have will grab any listing updated within the last 6 hours (give myself a window in case something goes wrong). However, I see a lot of real estate developers suggest creating 'batch' processes that run through all listings regardless of updated status that is constantly running. Is this the better way to do it? Or am I fine with just grabbing the data I know I need? It doesn't make a lot of sense to me to do more processing than necessary. Thoughts?

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  • Defining Light Coordinates

    - by Zachary
    I took a Computer Graphics exam a couple of days ago which had extra credit question like the following: A light can be defined in one of two ways. It can be defined in world coordinates, e.g. a street light, or in the viewer (eye coordinates), e.g., a head-lamp worn by a miner. In either case the viewpoint can freely change. Describe how the light should be transformed different in these two cases. Since I won't get to see the results of this until after spring break, I thought I would ask here. It seems like the analogies being used are misleading - could you not define a light source that is located at the viewers eye in world coordinates just as well as you could in eye coordinates? I've been doing some research on how OpenGL handles light, and it seems as though it always uses eye coordinates - the ModelView matrix would be applied to any light in world coordinates. In that case the answer may just be that you would have to transform light defined in world coordinates into eye coordinates using something like the ModelView matrix, while light defined in eye coordinates would only need to be transformed by the projection matrix. Then again I could be totally under thinking (or over thinking this). Another thought I had is that it determines which way you render shadows, but that has more to do with the location of the light and its type (point, directional, emission, etc) than what coordinates it is represented in. Any ideas?

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  • Flash As3 Mute Button problems

    - by Lee
    Hey guys, I am trying to create a UI movie clip that can be used across different scenes. It uses variables from the root scope to determine states. When i press the mute button is works fine, however when i try to un-mute things go weird. Sometimes it takes 2 clicks to unmute, sometimes more. It seems random. Muting however seems to work first time.. Any ideas? Main Timeline: var mute:Boolean = false; var playerName = "Fred"; function setMute(vol) { var sTransform:SoundTransform = new SoundTransform(1,0); sTransform.volume = vol; SoundMixer.soundTransform = sTransform; } function toggleMuteBtn(event:Event) { if (mute) { // Sound On, Mute Off mute = false; setMute(1); ui_mc.muteCross_mc.visible = false; } else { // Sound Off, Mute On mute = true; setMute(0); ui_mc.muteCross_mc.visible = true; } } ui_mc Action Script: if (MovieClip(parent).mute == false) { muteCross_mc.visible = false; } mute_btn.addEventListener(MouseEvent.CLICK, MovieClip(parent).toggleMuteBtn);

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  • Neural Network settings for fast training

    - by danpalmer
    I am creating a tool for predicting the time and cost of software projects based on past data. The tool uses a neural network to do this and so far, the results are promising, but I think I can do a lot more optimisation just by changing the properties of the network. There don't seem to be any rules or even many best-practices when it comes to these settings so if anyone with experience could help me I would greatly appreciate it. The input data is made up of a series of integers that could go up as high as the user wants to go, but most will be under 100,000 I would have thought. Some will be as low as 1. They are details like number of people on a project and the cost of a project, as well as details about database entities and use cases. There are 10 inputs in total and 2 outputs (the time and cost). I am using Resilient Propagation to train the network. Currently it has: 10 input nodes, 1 hidden layer with 5 nodes and 2 output nodes. I am training to get under a 5% error rate. The algorithm must run on a webserver so I have put in a measure to stop training when it looks like it isn't going anywhere. This is set to 10,000 training iterations. Currently, when I try to train it with some data that is a bit varied, but well within the limits of what we expect users to put into it, it takes a long time to train, hitting the 10,000 iteration limit over and over again. This is the first time I have used a neural network and I don't really know what to expect. If you could give me some hints on what sort of settings I should be using for the network and for the iteration limit I would greatly appreciate it. Thank you!

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  • PHP - Database schema: version control, branching, migrations.

    - by Billiam
    I'm trying to come up with (or find) a reusable system for database schema versioning in php projects. There are a number of Rails-style migration projects available for php. http://code.google.com/p/mysql-php-migrations/ is a good example. It uses timestamps for migration files, which helps with conflicts between branches. General problem with this kind of system: When development branch A is checked out, and you want to check out branch B instead, B may have new migration files. This is fine, migrating to newer content is straight forward. If branch A has newer migration files, you would need to migrate downwards to the nearest shared patch. If branch A and B have significantly different code bases, you may have to migrate down even further. This may mean: Check out B, determine shared patch number, check out A, migrate downwards to this patch. This must be done from A since the actual applied patches are not available in B. Then, checkout branch B, and migrate to newest B patch. Reverse process again when going from B to A. Proposed system: When migrating upwards, instead of just storing the patch version, serialize the whole patch in database for later use, though I'd probably only need the down() method. When changing branches, compare patches that have been run to patches that are available in the destination branch. Determine nearest shared patch (or oldest difference, maybe) between db table of run patches and patches in destination branch by ID or hash. Could also look for new or missing patches that are buried under a number of shared patches between the two branches. Automatically merge down to the nearest shared patch, using the db table stored down() methods, and then merge up to the branche's latest patch. My question is: Is this system too crazy and/or fraught with consequences to bother developing? My experience with database schema versioning is limited to PHP autopatch, which is an up()-only system requiring filenames with sequential IDs.

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  • jQuery ui Accordion degrades in IE6 or IE7, but is working in IE8

    - by cfree
    There are two accordions on my page, with custom accordion CSS in another file, differentiated by class and ID names so as not to conflict with each other. The accordions don't show up at all, they just degrade to showing all the content at once, as if all the accordion styling is gone. The accordions are both called around the middle of the page, and there's no difference if they are loaded with $(document).ready. What should I check for in the CSS files? There are no inline-block uses. I am using jQuery 1.3.2.min and jQuery ui 1.7.2, so I'm assuming the autoHeight set to false won't make a difference... This is being used inside a Symfony-based site. Works fine in FF, IE8, Chrome. Not so much in IE6, IE7/IE8 compatibility mode. $(function() { $("#accordion").accordion({ active: false, autoHeight: false, collapsible: true, icons: { 'header': 'ui-icon-carat-1-e', 'headerSelected': 'ui-icon-carat-1-s' }, }); $(".links").accordion({ active: false, autoHeight: false, collapsible: true }); });

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