Search Results

Search found 20211 results on 809 pages for 'language implementation'.

Page 667/809 | < Previous Page | 663 664 665 666 667 668 669 670 671 672 673 674  | Next Page >

• Collision detections and how efficient they are

  - by Shadow

  How exactly do you implement collision detection? What are the costs involved? Do different platforms(c/c++, java, cocoa/iphone, flash, directX) have different optimizations for calculating collisions. And lastly are there libraries available to do this for me, or some that I can just interpret for my platform of choice? As I understand it you would need to loop through the collision map and find the area in question and then compair the input thing(e.g. a sprite) to the type of pixel that is in the questioned area. I understand the very basic idea, but I don't understand the underlying implementation or even a higher level one for that matter. It would seem that this type of detection, or any for that matter, is very costly. Tile map? Bit array? How are these created from an image(I would guess looping and doing stuff)? The reason I ask this question is to get a better understanding of the efficiency behind the scenes and to understand exactly what is going on. Links, references, or examples would be very helpful. I know this question is a bit longwinded so any help or references would be very welcome. Thanks SO!

  Read the article

• Getting jQuery datepicker to attach to a TextBox within a ListView

  - by Clay

  I am using the jQuery Datepicker without any problem for TextBox controls that are non-templated. However, I am unable to get the datepicker to work with a TextBox that is in an EditItemTemplate of a ListView control. My latest attempt is to get a handle on this textbox by CSS class name "DateControl", any ideas? <asp:ListVIew id="lvTest" runat="server"> <LayoutTemplate>...</LayoutTemplate> <ItemTemplate>...</ItemTemplate> <EditItemTemplate> <tr> <td> <asp:TextBox ID="txtExpReceiveDate" runat="server" Text='<%#Eval("exp_receive_date","{0:dd-MMM-yy}") %>' CssClass="DateControl" /> </td> </tr> </EditTemplate> </asp:ListView> <script type="text/javascript" language="javascript"> $(document).ready(function () { $('DateControl').datepick({ dateFormat: 'M-dd-yyyy' }); }); </script>

  Read the article

• Opaque tenant identification with SQL Server & NHibernate

  - by Anton Gogolev

  Howdy! We're developing a nowadays-fashionable multi-tenanted SaaS app (shared database, shared schema), and there's one thing I don't like about it: public class Domain : BusinessObject { public virtual long TenantID { get; set; } public virtual string Name { get; set; } } The TenantID is driving me nuts, as it has to be accounted for almost everywhere, and it's a hassle from security standpoint: what happens if a malicious API user changes TenantID to some other value and will mix things up. What I want to do is to get rid of this TenantID in our domain objects altogether, and to have either NHibernate or SQL Server deal with it. From what I've already read on the Internets, this can be done with CONTEXT_INFO (here's a NHibernatebased implementation), NHibernate filters, SQL Views and with combination thereof. Now, my requirements are as follows: Remove any mentions of TenantID from domain objects ...but have SQL Server insert it where appropriate (I guess this is achieved with default constraints) ...and obviously provide support for filtering based on this criteria, so that customers will never see each other's data If possible, avoid SQL Server views. Have a solution which plays nicely with NHibernate, SQL Servers' MARS and general nature of SaaS apps being highly concurrent What are your thoughts on that?

  Read the article

• Web development: Haskell or Scheme

  - by Robert E. Lester

  I would like to to choose one of these languages for building web applications. I'm not interested in framework per say, but have the following needs: Rapid development. Easy to scale. Strong community for the web. Quick and easy to deploy. I'm very familiar with Haskell, and have some familiarity with scheme (in particular PLT). Scheme appeals to me as good candidate for web development due to it's simple syntax which is homogenous across libraries. I state this despite my subjective opinion that Haskell is a 'cleaner' language. Haskell web apps seem to require learning and building a patchwork of different combinator libraries. On the plus side, I realise this can be quite expressive, although I'd prefer to eliminate impedance mismatches where possible. While scheme-plt looks to be a good fit, I can find but one example of it being used in the "real world". Haskell doesn't seem to fair too much better here, but there seems to be a bigger community behind the web side. Please help me make up my mind. For the most part I'm interested in real-world use cases.

  Read the article

• My cocoa app won't capture key events

  - by Oscar

  Hi, i usually develop for iPhone. But now trying to make a pong game in Cocoa desktop application. Working out pretty well, but i can't find a way to capture key events. Here's my code: #import "PongAppDelegate.h" #define GameStateRunning 1 #define GameStatePause 2 #define BallSpeedX 10 #define BallSpeedY 15 @implementation PongAppDelegate @synthesize window, leftPaddle, rightPaddle, ball; - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { gameState = GameStateRunning; ballVelocity = CGPointMake(BallSpeedX, BallSpeedY); [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(gameLoop) userInfo:nil repeats:YES]; } - (void)gameLoop { if(gameState == GameStateRunning) { [ball setFrameOrigin:CGPointMake(ball.frame.origin.x + ballVelocity.x, ball.frame.origin.y + ballVelocity.y)]; if(ball.frame.origin.x + 15 > window.frame.size.width || ball.frame.origin.x < 0) { ballVelocity.x =- ballVelocity.x; } if(ball.frame.origin.y + 35 > window.frame.size.height || ball.frame.origin.y < 0) { ballVelocity.y =- ballVelocity.y; } } } - (void)keyDown:(NSEvent *)theEvent { NSLog(@"habba"); // Arrow keys are associated with the numeric keypad if ([theEvent modifierFlags] & NSNumericPadKeyMask) { [window interpretKeyEvents:[NSArray arrayWithObject:theEvent]]; } else { [window keyDown:theEvent]; } } - (void)dealloc { [ball release]; [rightPaddle release]; [leftPaddle release]; [super dealloc]; } @end

  Read the article

• Python to C# with openSSL requirement

  - by fonix232

  Hey there again! Today I ran into a problem when I was making a new theme creator for chrome. As you may know, Chrome uses a "new" file format, called CRX, to manage it's plugins and themes. It is a basic zip file, but a bit modified: "Cr24" + derkey + signature + zipFile And here comes the problem. There are only two CRX creators, written in Ruby or Python. I don't know neither language too much (had some basic experience in Python though, but mostly with PyS60), so I would like to ask you to help me convert this python app to a C# class. Also, here is the source of crxmake.py: #!/usr/bin/python # Cribbed from http://github.com/Constellation/crxmake/blob/master/lib/crxmake.rb # and http://src.chromium.org/viewvc/chrome/trunk/src/chrome/tools/extensions/chromium_extension.py?revision=14872&content-type=text/plain&pathrev=14872 # from: http://grack.com/blog/2009/11/09/packing-chrome-extensions-in-python/ import sys from array import * from subprocess import * import os import tempfile def main(argv): arg0,dir,key,output = argv # zip up the directory input = dir + ".zip" if not os.path.exists(input): os.system("cd %(dir)s; zip -r ../%(input)s . -x '.svn/*'" % locals()) else: print "'%s' already exists using it" % input # Sign the zip file with the private key in PEM format signature = Popen(["openssl", "sha1", "-sign", key, input], stdout=PIPE).stdout.read(); # Convert the PEM key to DER (and extract the public form) for inclusion in the CRX header derkey = Popen(["openssl", "rsa", "-pubout", "-inform", "PEM", "-outform", "DER", "-in", key], stdout=PIPE).stdout.read(); out=open(output, "wb"); out.write("Cr24") # Extension file magic number header = array("l"); header.append(2); # Version 2 header.append(len(derkey)); header.append(len(signature)); header.tofile(out); out.write(derkey) out.write(signature) out.write(open(input).read()) os.unlink(input) print "Done." if __name__ == '__main__': main(sys.argv) Please could you help me?

  Read the article

• paging helper asp.net mvc

  - by csetzkorn

  Hi, I have implemented a paging html helper (adapted from steven sanderson's book). This is the current code: public static string PageLinks(this HtmlHelper html, int currentPage, int totalPages, Func pageUrl) { StringBuilder result = new StringBuilder(); for (int i = 1; i <= totalPages; i++) { TagBuilder tag = new TagBuilder("a"); tag.MergeAttribute("href", pageUrl(i)); tag.InnerHtml = i.ToString(); if (i == currentPage) tag.AddCssClass("selectedPage"); result.AppendLine(tag.ToString()); } return result.ToString(); } This produces a bunch of links to each page of my items. If there are many pages this can be a bit overwhelming. I am looking for a similar implementation which produces something less overwhelming like this: where 6 is the current page. I am sure someone must have implemented something similar ... before I have to re-implement the wheel. Thanks. Christian

  Read the article

• How to allow one thread to mutate an array property while another thread iterates on a copy of the a

  - by Steve918

  I would like to implement an observer pattern in Objective-C where the observer implements an interface similar to SKPaymentTransactionObserver and the observable class just extends my base observable. My observable class looks something like what is below. Notice I'm making copies of the observers before enumeration to avoid throwing an exception . I've tried adding an NSLock around add observers and notify observers, but I run into a deadlock. What would be the proper way to handle concurrency when observers are being added as notifications are being sent? @implementation Observable -(void)notifyObservers:(SEL)selector { @synchronized(self) { NSSet* observer_copy = [observers copy]; for (id observer in observer_copy) { if([observer respondsToSelector: selector]) { [observer performSelector: selector]; } } [observer_copy release]; } } -(void)notifyObservers:(SEL)selector withObject:(id)arg1 withObject:(id)arg2 { @synchronized(self) { NSSet* observer_copy = [observers copy]; for (id observer in observer_copy) { if([observer respondsToSelector: selector]) { [observer performSelector: selector withObject: arg1 withObject: arg2]; } } [observer_copy release]; } } -(void)addObserver:(id)observer { @synchronized(self) { [observers addObject: observer]; } } -(void)removeObserver:(id)observer { @synchronized(self) { [observers removeObject: observer]; } }

  Read the article

• hadoop implementing a generic list writable

  - by Guruprasad Venkatesh

  I am working on building a map reduce pipeline of jobs(with one MR job's output feeding to another as input). The values being passed around are fairly complex, in that there are lists of different types and hash maps with values as lists. Hadoop api does not seem to have a ListWritable. Am trying to write a generic one, but it seems i can't instantiate a generic type in my readFields implementation, unless i pass in the class type itself: public class ListWritable<T extends Writable> implements Writable { private List<T> list; private Class<T> clazz; public ListWritable(Class<T> clazz) { this.clazz = clazz; list = new ArrayList<T>(); } @Override public void write(DataOutput out) throws IOException { out.writeInt(list.size()); for (T element : list) { element.write(out); } } @Override public void readFields(DataInput in) throws IOException{ int count = in.readInt(); this.list = new ArrayList<T>(); for (int i = 0; i < count; i++) { try { T obj = clazz.newInstance(); obj.readFields(in); list.add(obj); } catch (InstantiationException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } } } But hadoop requires all writables to have a no argument constructor to read the values back. Has anybody tried to do the same and solved this problem? TIA.

  Read the article

• What are the most time consuming checks performed by .NET when executing a managed appplication?

  - by ltorje

  I've developed a .NET based Windows service that uses part managed (C#) and unmanaged code (C/C++ libraries). In some domain environments (e.g. Win 2k3 32bit server inside domain abc.com) sometimes the service takes more than 30 seconds to start (especially on OS restart), thus failing to start the service. I suspect that it has something to do with enterprise level security but I do not know for sure. http://msdn.microsoft.com/en-us/library/aa720255%28VS.71%29.aspx I've tried the following without success: - delay loading references by moving the using directives as far as possible from the servicebase implementation (especially the xml namespace - know to cause delays in loading) - delay loading and configuring log4net - precompiling the code by using ngen - delaying the start of the worker thread - add/remove manifest + decencies set inside - sign/unsign the binaries - use the configuration settings (there are a lot of settings and the scope level for all is set to application ) as later as possible - add all dependencies to GAC I didn't tried yet to add security demands for the class that has the Main method implemented. I didn't tries to implement my own configuration loader because after inspecting the autogenerated code, I've noticed that the setting class is a singletone and it gets its instance on call. By completely removing the log4net dependency it worked, but this is not an option. When the network card is disabled the service starts immediately. Any suggestions/comments/solution you have would be most welcomed.

  Read the article

• Suppressing PostSharp Multicast with Attribute

  - by Dan Bryant

  I've recently started experimenting with PostSharp and I found a particularly helpful aspect to automate implementation of INotifyPropertyChanged. You can see the example here. The basic functionality is excellent (all properties will be notified), but there are cases where I might want to suppress notification. For instance, I might know that a particular property is set once in the constructor and will never change again. As such, there is no need to emit the code for NotifyPropertyChanged. The overhead is minimal when classes are not frequently instantiated and I can prevent the problem by switching from an automatically generated property to a field-backed property and writing to the field. However, as I'm learning this new tool, it would be helpful to know if there is a way to tag a property with an attribute to suppress the code generation. I'd like to be able to do something like this: [NotifyPropertyChanged] public class MyClass { public double SomeValue { get; set; } public double ModifiedValue { get; private set; } [SuppressNotify] public double OnlySetOnce { get; private set; } public MyClass() { OnlySetOnce = 1.0; } }

  Read the article

• How do I get started designing and implementing a script interface for my .NET application?

  - by Peter Mortensen

  How do I get started designing and implementing a script interface for my .NET application? There is VSTA (the .NET equivalent of VBA for COM), but as far as I understand I would have to pay a license fee for every installation of my application. It is an open source application so this will not work. There is also e.g. the embedding of interpreters (IronPython?), but I don't understand how this would allow exposing an "object model" (see below) to external (or internal) scripts. What is the scripting interface story in .NET? Is it somehow trivial in .NET to do this? Background: I have once designed and implemented a fairly involved script interface for a Macintosh application for acquisition and analysis of data from a mass spectrometer (Mac OS, System 7) and later a COM interface for a Windows application. Both were designed with an "object model" and classes (that can have properties). These are overloaded words, but in a scripting interface context object model is essentially a containment hiarchy of objects of specific classes. Classes have properties and lists of contained objects. E.g. like in the COM interfaces exposed in Microsoft Office applications, where the application object can be used to add to its list of documents (with the side effect of creating the GUI representation of a document). External scripts can create new objects in a container and navigate through the content of the hiarchy at any given time. In the Macintosh case scripts could be written in e.g. AppleScript or Frontier. On the Macintosh the implementation of a scripting interface was very complicated. Support for it in Metroworks' C++ class library (the name escapes me right now) made it much simpler.

  Read the article

• questions about name mangling in C++

  - by Tim

  I am trying to learn and understand name mangling in C++. Here are some questions: (1) From devx When a global function is overloaded, the generated mangled name for each overloaded version is unique. Name mangling is also applied to variables. Thus, a local variable and a global variable with the same user-given name still get distinct mangled names. Are there other examples that are using name mangling, besides overloading functions and same-name global and local variables ? (2) From Wiki The need arises where the language allows different entities to be named with the same identifier as long as they occupy a different namespace (where a namespace is typically defined by a module, class, or explicit namespace directive). I don't quite understand why name mangling is only applied to the cases when the identifiers belong to different namespaces, since overloading functions can be in the same namespace and same-name global and local variables can also be in the same space. How to understand this? Do variables with same name but in different scopes also use name mangling? (3) Does C have name mangling? If it does not, how can it deal with the case when some global and local variables have the same name? C does not have overloading functions, right? Thanks and regards!

  Read the article

• php fopen function dies, though I have file permissions set to read and write

  - by Matthew Robert Keable

  I'm following a tutorial on php, and am having difficulty getting this to work. I set the appropriate directory permissions to read and write, but every time I run this, I get the die string. The code is: $ourFileName = "testFile.txt"; $ourFileHandle = fopen($ourFileName, 'w') or die("can't open file"); fclose($ourFileHandle); As far as my basic understanding goes, if "testFile.txt" does not exist, fopen should create that file (I have basic knowledge of Python, and remember this same principle in that language). But it...it doesn't. Even if I create the aforementioned file, and put it up, that line of code still returns a die string. My hosting account does not give me permission to execute. Is this a problem? My server runs on Windows. I am using Dreamweaver CS5, on OSX 10.5.8. I've done some searching on this, and see other people having similar issues - but none of them keyed to exactly my range of problems. Being that I'm a beginner, I feel that it might be something I'm overlooking. Thanks!!

  Read the article

• Relative Paths in .htaccess, how to attach to a variable?

  - by devians

  I have a very heavy htaccess mod_rewrite file that runs my application. As we sometimes take over legacy websites, I sometimes need to support old urls to old files, where my application processes everything post htaccess. My ultimate goal is to have a 'Demilitarized Zone' for old file structures, and use mod rewrite to check for existence there before pushing to the application. This is pretty easy to do with files, by using: RewriteCond %{IS_SUBREQ} true RewriteRule .* - [L] RewriteCond %{ENV:REDIRECT_STATUS} 200 RewriteRule .* - [L] RewriteCond Public/DMZ/$1 -F [OR] RewriteRule ^(.*)$ Public/DMZ/$1 [QSA,L] This allows pseudo support for relative urls by not hardcoding my base path (I cant assume I will ever be deployed in document root) anywhere and using subrequests to check for file existence. Works fine if you know the file name, ie http://domain.com/path/to/app/legacyfolder/index.html However, my legacy urls are typically http://domain.com/path/to/app/legacyfolder/ Mod_Rewrite will allow me to check for this by using -d, but it needs the complete path to the directory, ie RewriteCond Public/DMZ/$1 -F [OR] RewriteCond /var/www/path/to/app/Public/DMZ/$1 -d RewriteRule ^(.*)$ Public/DMZ/$1 [QSA,L] I want to avoid the hardcoded base path. I can see one possible solutions here, somehow determining my path and attaching it to a variable [E=name:var] and using it in the condition. Any implementation that allows me to existence check a directory is more than welcome.

  Read the article

• PHPExcel reading columns

  - by user1270150

  I am new to using the PHPExcel and am struggling to implement a basic reader that can be used to read only specified columns, with all rows from a spreadsheet into an array, which I would like to present in a webpage. After reading the supplied documentation and examples, I am struggling to wrap my head round the implementation of a number of examples, so any help would be much appreciated. I am using the following code to get the contents of the default worksheet into an array: for ($row = 2; $row <= $highestRow; $row++) { $dataRow = $objWorksheet->rangeToArray('A'.$row.':'.$highestColumn.$row,null, true, true, true); if ((isset($dataRow[$row]['A'])) && ($dataRow[$row]['A'] > '')) { ++$r; foreach($headingsArray as $columnKey => $columnHeading) { $columnHeading = rtrim($columnHeading); $columnHeading = preg_replace('/\s+/', ' ',$columnHeading); $columnHeading = preg_replace('/\ /', '_',$columnHeading); $columnHeading = strtolower($columnHeading); $namedDataArray[$r][$columnHeading] = $dataRow[$row][$columnKey]; } } } Above code reads through all the columns and rows and builds and array, but I would like to be able to add a configuration array that will declare columns that should be read...sure this is possible, so any help would be much appreciated. Thanks

  Read the article

• C Run-Time library part 2

  - by b-gen-jack-o-neill

  Hi, I was suggested when I have some further questions on my older ones, to create newer Question and reffer to old one. So, this is the original question: What is the C runtime library? OK, from your answers, I now get thet statically linked libraries are Microsoft implementation of C standart functions. Now: If I get it right, the scheme would be as follow: I want to use printf(), so I must include which just tels compiler there us functio printf() with these parameters. Now, when I compile code, becouse printf() is defined in C Standart Library, and becouse Microsoft decided to name it C Run Time library, it gets automatically statically linked from libcmt.lib (if libcmt.lib is set in compiler) at compile time. I ask, becouse on wikipedia, in article about runtime library there is that runtime library is linked in runtime, but .lib files are linked at compile time, am I right? Now, what confuses me. There is .dll version of C standart library. But I thought that to link .dll file, you must actually call winapi program to load that library. So, how can be these functions dynamically linked, if there is no static library to provide code to tell Windows to load desired functions from dll? And really last question on this subject - are C Standart library functions also calls to winapi even they are not .dll files like more advanced WinAPI functions? I mean, in the end to access framebuffer and print something you must tell Windows to do it, since OS cannot let you directly manipulate HW. I think of it like the OS must be written to support all C standart library functions same way across similiar versions, since they are statically linked, and can differently support more complex WinAPI calls becouse new version of OS can have adjustements in the .dll file.

  Read the article

• How can i get rid of 0xFEEFEE in VC

  - by egebilmuh

  Hi guys I m programming C for an assingment in VC++ 2008. I simulate adjList for graph implementation. i can readly add edge between two vertex and print the graph. and i want to remove edge between two vertex and print the graph again. whatever i do,i cant print the graph after deleting the edge. i get 0xfeefee :( what is this? and how can i resolve this program. my delete function and print the graph function are illustrated below. void deleteEdge(Graph G, Vertex V, Vertex W) { Edge list,prev,temp; list=V->list; prev=NULL; // while(list!=NULL && list->to->value!=W->value){ prev=list; list=list->next; } // have found the element. if(list!=NULL){ temp=list; // if first element of list is deleted. if(prev==NULL) list=list->next; else prev->next=list->next; // reallocate. free(temp); } } void GRAPHprint(Graph G) { Vertex tmp; Edge list; for(tmp = G->head;tmp!=NULL;tmp=tmp->next) { fprintf(stdout,"V:%d\t",tmp->value); list=tmp->list; while(list!=NULL) { fprintf(stdout,"%d\t",list->to->value); list=list->next; } fprintf(stdout, "\n"); } system("pause"); }

  Read the article

• Ideas on frameworks in .NET that can be used for job processing and notifications

  - by Rajat Mehta

  Scenario: We have one instance of WCF windows service which exposes contracts like: AddNewJob(Job job), GetJobs(JobQuery query) etc. This service is consumed by 70-100 instances of client which is Windows Form based .NET app. Typically the service has 50-100 inward calls/minute to add or query jobs that are stored in a table on Sql Server. The same service is also responsible for processing these jobs in real time. It queries database every 5 seconds picks up the queued jobs and starts processing them. A job has 6 states. Queued, Pre-processing, Processing, Post-processing, Completed, Failed, Locked. Another responsibility on this service is to update all clients on every state change of every job. This means almost 200+ callbacks to clients per second. Question: This whole implementation is done using WCF Duplex bindings and works perfectly fine on small number of parallel jobs. Problem arises when we scale it up to 1000 jobs at a time. The notifications don't work as expected, it leads to memory overflow etc. Is there any standard framework that can provide a clean infrastructure for handling this scenario?? Apologies for the long explanation!

  Read the article

• Retrieve OpenId FullName from Google

  - by user294711

  I'm using DotNetOpenAuth lib to work with Google(only) OpenId. And I'm retrieving Email without any problem. But I can't get FullName, it is always null. request.AddExtension(new ClaimsRequest { Email = DemandLevel.Require, FullName = DemandLevel.Require }); ClaimsResponse claimsResponse = relyingPartyResponse.GetExtension<ClaimsResponse>(); if (claimsResponse != null) { var email = claimsResponse.Email; var fullName = claimsResponse.FullName; } I googled this problem and found that: Glad you got it working. Google will not give a full name or nickname for their users. They ONLY give email address, and (I think, but perhaps only on a white list) the timezone. It's not a matter of figuring out how to rig your RP so that it works. Google just won't do it yet. – Andrew Arnott Sep 8 at 14:22 stackoverflow.com/questions/1387438/retrieve-openid-user-information-claims-across-providers But it was in Sep 2009, maybe something was changed from that moment... I've found that in http://code.google.com/apis/accounts/docs/OpenID.html: openid.ax.required -- (required) Specifies the attribute being requested. Valid values include: "country", "email", "firstname", "language", "lastname". To request multiple attributes, set this parameter to a comma-delimited list of attributes. So, my question is how can I get FullName (FirstName, LastName) from Google OpenId?

  Read the article

• BinaryWriterWith7BitEncoding & BinaryReaderWith7BitEncoding

  - by Tim

  Mr. Ayende wrote in his latest blog post about an implementation of a queue. In the post he's using two magical files: BinaryWriterWith7BitEncoding & BinaryReaderWith7BitEncoding BinaryWriterWith7BitEncoding can write both int and long? using the following method signatures: void WriteBitEncodedNullableInt64(long? value) & void Write7BitEncodedInt(int value) and BinaryReaderWith7BitEncoding can read the values written using the following method signatures: long? ReadBitEncodedNullableInt64() and int Read7BitEncodedInt() So far I've only managed to find a way to read the 7BitEncodedInt: protected int Read7BitEncodedInt() { int value = 0; int byteval; int shift = 0; while(((byteval = ReadByte()) & 0x80) != 0) { value |= ((byteval & 0x7F) << shift); shift += 7; } return (value | (byteval << shift)); } I'm not too good with byte shifting - does anybody know how to read and write the 7BitEncoded long? and write the int ?

  Read the article

• How to implement Horner's scheme for multivariate polynomials?

  - by gsreynolds

  Background I need to solve polynomials in multiple variables using Horner's scheme in Fortran90/95. The main reason for doing this is the increased efficiency and accuracy that occurs when using Horner's scheme to evaluate polynomials. I currently have an implementation of Horner's scheme for univariate/single variable polynomials. However, developing a function to evaluate multivariate polynomials using Horner's scheme is proving to be beyond me. An example bivariate polynomial would be: 12x^2y^2+8x^2y+6xy^2+4xy+2x+2y which would factorised to x(x(y(12y+8))+y(6y+4)+2)+2y and then evaluated for particular values of x & y. Research I've done my research and found a number of papers such as: staff.ustc.edu.cn/~xinmao/ISSAC05/pages/bulletins/articles/147/hornercorrected.pdf citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.40.8637&rep=rep1&type=pdf www.is.titech.ac.jp/~kojima/articles/B-433.pdf Problem However, I'm not a mathematician or computer scientist, so I'm having trouble with the mathematics used to convey the algorithms and ideas. As far as I can tell the basic strategy is to turn a multivariate polynomial into separate univariate polynomials and compute it that way. Can anyone help me? If anyone could help me turn the algorithms into pseudo-code that I can implement into Fortran myself, I would be very grateful.

  Read the article

• substitution cypher with different alphabet length

  - by seanizer

  I would like to implement a simple substitution cypher to mask private ids in URLs I know how my IDs will look like (combination of upperchase ascii, digits and underscore), and they will be rather long, as they are composed keys. I would like to use a longer alphabet to shorten the resulting codes (I'd like to use upper and lower case ascii letters, digits and nothing else). So my incoming alphabet would be [A-Z0-9_] (37 chars) and my outgoing alphabet would be [A-Za-z0-9] (62 chars) so a compression of almost 50% would be available. let's say my URLs look like this: /my/page/GFZHFFFZFZTFZTF_24_F34 and I want them to look like this instead: /my/page/Ft32zfegZFV5 Obviously both arrays would be shuffled to bring some random order in. This does not have to be secure. if someone figures it out: fine, but I don't want the scheme to be obvious. My desired solution would be to convert the string to an integer representation of radix 37, convert the radix to 62 and use the second alphabet to write out that number. is there any sample code available that does something similar? Integer.parseInt ( http://java.sun.com/javase/6/docs/api/java/lang/Integer.html#parseInt%28java.lang.String,%20int%29 ) has some similar logic, but it is hard-coded to use standard digit behavior Any hints? I am using java to implement this but code or pseudo-code in any other language is of course also helpful

  Read the article

• Force a view change from a button when using UITabBarController

  - by user342197

  Hello - When using a UITabBarController, when the user enters some data on View1 and presses a button, I need to perform some calculations and present the results on View2. I have an AppDelegate, View1Controller, View2Controller, and View3Controller (View3 is a basically static view). My AppDelgate declares UITabBarController *rootController; On View1, I have the calculations being performed in an IBAction for buttonPressed; however, I can't seem to force the view to switch to View2 programmatically. I have done a lot of searching for similar problems, and think I should be doing something like "self.rootController.selectedIndex = 1"; however,when I do this from within buttonPressed on my View1Controller, I get an error "request for member rootController in something not in a structure or union". I think I'm missing something basic here... probably need do do something with my AppDelegate, but I'm banging my head against the wall. Can anyone provide some guidance in this situation...like key things I should do in View1Controller header and implementation with reference to my AppDelgate? Thank you!

  Read the article

• JMF microphone volume controller

  - by TacB0sS

  How to obtain the Microphone volume controller in JMF? this is what I have: I tried this implementation concept of yours, but I keep getting a null from the first volume processor when I try to get the stream, here is how I do it: // the device is the media device specifically audio Processor processorForVolume = Manager.createProcessor(device.getLocator()); // wait until configured ProcessorStates newState = new ProcessorStateListener(Processor.Configured).waitForProcessorState(processorForVolume); System.out.println("volumeProcessorState: "+newState); // setting the content descriptor to null - read in another thread this allows to get the gain control processorForVolume.setContentDescriptor(null); // set the track control format to one supported by the device and the track control. // I didn't match it to an RTP allowed format, but I don't think this has anything to do with it... TrackControl[] trackControls = processorForVolume.getTrackControls(); if (trackControls.length == 0) throw new MC_Exception("No track controls where found for this device:", new Object[]{device}); for (TrackControl control : trackControls) trackManipulator.manipulateTrackControls(control); // wait until the processor is realized newState = new ProcessorStateListener(Controller.Realized).waitForProcessorState(processorForVolume); System.out.println("volumeProcessorState: "+newState); // receives the gain control micVolumeController = processorForVolume.getGainControl(); // cannot get the output stream to process further... any suggestions? processor = Manager.createProcessor(processorForVolume.getDataOutput()); new ProcessorStateListener(Processor.Configured).waitForProcessorState(processor); processor.setContentDescriptor(DeviceCapturingManager.RAW_RTP); new ProcessorStateListener(Controller.Realized).waitForProcessorState(processor); this is the output It generates: volumeProcessorState: Configured format set to track control - com.sun.media.ProcessEngine$ProcTControl@1627c16: LINEAR, 48000.0 Hz, 16-bit, Stereo, LittleEndian, Signed volumeProcessorState: Realized and the data output from the processor is Null. I should make clear that when the content descriptor != null I do get an output stream but not the volume controller, and the when it is null I get the controller, but no stream. I try to connect to an audio microphone device Adam.

  Read the article

< Previous Page | 663 664 665 666 667 668 669 670 671 672 673 674  | Next Page >