Search Results

Search found 558 results on 23 pages for 'computed observable'.

Page 11/23 | < Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18  | Next Page >

  • Rotating a view of a chunked 2d tilemap

    - by Danie Clawson
    I'm working on a top-down (oblique) tile-based engine. I would like for the tiles to have a definable height in the world, with Characters being occluded by them, etc. This has led to a desire to be able to "rotate" the view of the world, even though I'm using all hand-drawn graphics and blitting. Therefor, I need to rotate the actual world itself, or change how the Camera traverses these arrays. How can, or should, I create individual rotations of 90 degrees, when I have multi-dimensional arrays? Is it faster to actually rotate the array, to access it differently, or to create pre-computed accessor(?) arrays, something like how my chunks work? How can I rotate an individual chunk, or set of chunks? Currently I establish my tile grid like this (tile height not included): function Surface(WIDTH, HEIGHT) { WIDTH = Math.max(WIDTH-(WIDTH%TPC), TPC); HEIGHT = Math.max(HEIGHT-(HEIGHT%TPC), TPC); this.tiles = []; this.chunks = []; //Establish tiles for(var x = 0; x < WIDTH; x++) { var col = [], ch_x = Math.floor(x/TPC); if(!this.chunks[ch_x]) this.chunks.push([]); for(var y = 0; y < HEIGHT; y++) { var tile = new Tile(x, y), ch_y = Math.floor(y/TPC); if(!this.chunks[ch_x][ch_y]) this.chunks[ch_x].push([]); this.chunks[ch_x][ch_y].push(tile); col.push(tile); } this.tiles.push(col); } }; Even some basic advice on my data struct would be much appreciated.

    Read the article

  • How common is it to submit papers to journals or conferences outside of academia?

    - by Furry
    I worked in academia a few years, but more on the D-side of R&D. The race for papers never appealed to me and I'm a practical not theoretical type, but I do like reading papers on certain topics (e.g. Google Papers, NLP, FB papers, ...) a lot. How common is it that normally working developers submit papers to conferences or even journals? It seems to be somewhat common in certain companies (it's not common or encouraged in mine). Do journals or conferences even take papers by an academic nobody (BSc) under consideration? I ask, because I have a few rough ideas and I would just like to bring them into form, one way or the other. Bonus question: Is there a list of CS (in the widest sense) conferences/journals with short descriptions? PS (Four out of five researchers I met published quite some fluffy stuff for my taste. I am no expert, but those people told me sometimes themselves, that the implementation does not matter, just the idea and the presentation. I always wondered about that. I probably could write about ideas all day long (not instantly but with a bit of preparation), but the implementation and the practical part is the really hard part, that academia just does not like to be concerned with. Also many papers actually scream: I was written so the publication list of my author gets longer - which is a waste of time for everyone, and often a waste of tax money, too. When I think of CS-ish papers, I think of running implementations or actual data, like e.g. Google's Map Reduce, Serving Large-scale Batch Computed Data with Project Voldemort or the like.)

    Read the article

  • Is NAN suitable for communicating that an invalid parameter was involved in a calculation?

    - by Arman
    I am currently working on a numerical processing system that will be deployed in a performance-critical environment. It takes inputs in the form of numerical arrays (these use the eigen library, but for the purpose of this question that's perhaps immaterial), and performs some range of numerical computations (matrix products, concatenations, etc.) to produce outputs. All arrays are allocated statically and their sizes are known at compile time. However, some of the inputs may be invalid. In these exceptional cases, we still want the code to be computed and we still want outputs not "polluted" by invalid values to be used. To give an example, let's take the following trivial example (this is pseudo-code): Matrix a = {1, 2, NAN, 4}; // this is the "input" matrix Scalar b = 2; Matrix output = b * a; // this results in {2, 4, NAN, 8} The idea here is that 2, 4 and 8 are usable values, but the NAN should signal to the receipient of the data that that entry was involved in an operation that involved an invalid value, and should be discarded (this will be detected via a std::isfinite(value) check before the value is used). Is this a sound way of communicating and propagating unusable values, given that performance is critical and heap allocation is not an option (and neither are other resource-consuming constructs such as boost::optional or pointers)? Are there better ways of doing this? At this point I'm quite happy with the current setup but I was hoping to get some fresh ideas or productive criticism of the current implementation.

    Read the article

  • Partial recalculation of visibility on a 2D uniform grid

    - by Martin Källman
    Problem Imagine that we have a 2D uniform grid of dimensions N x N. For this grid we have also pre-computed a visibility look-up table, e.g. with DDA, which answers the boolean query is cell X visible from cell Y? The look-up table is a complete graph KN of the cells V in the grid, with each edge E being a binary value denoting the visibility between its vertices. Question If any given cell has its visibility modified, is it possible to extract the subset Edelta of edges which must have their visibility recomputed due to the change, so as to avoid a full-on recomputation for the entire grid? (Which is N(N-1) / 2 or N2 depending on the implementation) Update If is not possible to solve thi in closed form, then maintaining a separate mapping of each cell and every cell pair who's line intersects said cell might also be an option. This obviously consumes more memory, but the data is static. The increased memory requirement could be reduced by introducing a hierarchy, subdividing the grid into smaller parts, and by doing so the above mapping can be reused for each sub-grid. This would come at a cost in terms of increased computation relative to the number of subdivisions; also requiring a resumable ray-casting algorithm.

    Read the article

  • Can a conforming C implementation #define NULL to be something wacky

    - by janks
    I'm asking because of the discussion that's been provoked in this thread: http://stackoverflow.com/questions/2597142/when-was-the-null-macro-not-0/2597232 Trying to have a serious back-and-forth discussion using comments under other people's replies is not easy or fun. So I'd like to hear what our C experts think without being restricted to 500 characters at a time. The C standard has precious few words to say about NULL and null pointer constants. There's only two relevant sections that I can find. First: 3.2.2.3 Pointers An integral constant expression with the value 0, or such an expression cast to type void * , is called a null pointer constant. If a null pointer constant is assigned to or compared for equality to a pointer, the constant is converted to a pointer of that type. Such a pointer, called a null pointer, is guaranteed to compare unequal to a pointer to any object or function. and second: 4.1.5 Common definitions <stddef.h> The macros are NULL which expands to an implementation-defined null pointer constant; The question is, can NULL expand to an implementation-defined null pointer constant that is different from the ones enumerated in 3.2.2.3? In particular, could it be defined as: #define NULL __builtin_magic_null_pointer Or even: #define NULL ((void*)-1) My reading of 3.2.2.3 is that it specifies that an integral constant expression of 0, and an integral constant expression of 0 cast to type void* must be among the forms of null pointer constant that the implementation recognizes, but that it isn't meant to be an exhaustive list. I believe that the implementation is free to recognize other source constructs as null pointer constants, so long as no other rules are broken. So for example, it is provable that #define NULL (-1) is not a legal definition, because in if (NULL) do_stuff(); do_stuff() must not be called, whereas with if (-1) do_stuff(); do_stuff() must be called; since they are equivalent, this cannot be a legal definition of NULL. But the standard says that integer-to-pointer conversions (and vice-versa) are implementation-defined, therefore it could define the conversion of -1 to a pointer as a conversion that produces a null pointer. In which case if ((void*)-1) would evaluate to false, and all would be well. So what do other people think? I'd ask for everybody to especially keep in mind the "as-if" rule described in 2.1.2.3 Program execution. It's huge and somewhat roundabout, so I won't paste it here, but it essentially says that an implementation merely has to produce the same observable side-effects as are required of the abstract machine described by the standard. It says that any optimizations, transformations, or whatever else the compiler wants to do to your program are perfectly legal so long as the observable side-effects of the program aren't changed by them. So if you are looking to prove that a particular definition of NULL cannot be legal, you'll need to come up with a program that can prove it. Either one like mine that blatantly breaks other clauses in the standard, or one that can legally detect whatever magic the compiler has to do to make the strange NULL definition work. Steve Jessop found an example of way for a program to detect that NULL isn't defined to be one of the two forms of null pointer constants in 3.2.2.3, which is to stringize the constant: #define stringize_helper(x) #x #define stringize(x) stringize_helper(x) Using this macro, one could puts(stringize(NULL)); and "detect" that NULL does not expand to one of the forms in 3.2.2.3. Is that enough to render other definitions illegal? I just don't know. Thanks!

    Read the article

  • CodePlex Daily Summary for Saturday, October 19, 2013

    CodePlex Daily Summary for Saturday, October 19, 2013Popular ReleasesMedia Companion: Media Companion MC3.583b: As before release but fixed for no movie poster sourcesNew* Both - Added 'An' as option to ignore in title * Movie - Renaming - added %Z - Sorttitle to Legend * Movie - Renaming - added %O - Audio Channels to Legend * Movie - Remove a poster source from priority list. Reset List back to defaults. * Made Media Companion truly portable application. Fixed* Movie - browse for Poster Or Fanart, allows for jpg, tbn, png and bmp images * Movie - Alt Fanart Browser - Url or Browse window now fully...MoreTerra (Terraria World Viewer): MoreTerra 1.11.3.1: Release 1.11.3.1 ================ = New Features = ================ Added markers for Copper Cache, Silver Cache and the Enchanted Sword. ============= = Bug Fixes = ============= Use Official Colors now no longer tries to change the Draw Wires option instead. World reading was breaking for people with a stock 1.2 Terraria version. Changed world name reading so it does not crash the program if you load MoreTerra while Terraria is saving the world. =================== = Feature Removal = =...patterns & practices - Windows Azure Guidance: Cloud Design Patterns: 1st drop of Cloud Design Patterns project. It contains 14 patterns with 6 related guidance.Json.NET: Json.NET 5.0 Release 8: Fix - Fixed not writing string quotes when QuoteName is falsePowerShell Community Extensions: 3.1 Production: PowerShell Community Extensions 3.1 Release NotesOct 17, 2013 This version of PSCX supports Windows PowerShell 3.0 and 4.0 See the ReleaseNotes.txt download above for more information.SQL Power Doc: Version 1.0.2.1: Misc. bug fixes Added logic to resolve members of a Windows Group server login Added columns to Excel workbooks to show definitions for server permissions, server roles, database permissions, and database rolesSocial Network Importer for NodeXL: SocialNetImporter(v.1.9): This new version includes: - Download latest status update and use it as vertex tooltip - Limit the timelines to parse to me, my friends or both - Fixed some reported bugs about the fan page and group importer - Fixed the login bug reported latelyDotNetNuke® Wiki: 05.00.00: Changes made to better support upgrades and the removal of deprecated legacy files that were causing formatting issues. Updated the Version number to better indicate the significance of the C# migration and the new DNN 7.0.2 minimum requirement.TerrariViewer: TerrariViewer v7.1 [Terraria Inventory Editor]: You can now backspace in number fields Items added in 1.2.0.3 no longer corrupt player files Buff durations capped at 9999999 Item stacks capped at 9999999 Version info added Prefix IDs corrected Shoe and Eye color box are now properly clickable Moved Bank and Safe into their own tab Users will now be notified of new updatesPython Tools for Visual Studio: 2.0: PTVS 2.0 We’re pleased to announce the release of Python Tools for Visual Studio 2.0 RTM. Python Tools for Visual Studio (PTVS) is an open-source plug-in for Visual Studio which supports programming with the Python language. PTVS supports a broad range of features including CPython/IronPython, Edit/Intellisense/Debug/Profile, Cloud, IPython, and cross platform and cross language debugging support. QUICK VIDEO OVERVIEW For a quick overview of the general IDE experience, please watch this v...C# Intellisense for Notepad++: Release v.1.0.8.2: Solved scrolling problem after DocumentFormatting Implemented "format as you type" --- To avoid the DLLs getting locked by OS use MSI file for the installation.CS-Script for Notepad++ (C# intellisense and code execution): Release v1.0.8.2: Solved scrolling problem after DocumentFormatting Implemented "format as you type" --- To avoid the DLLs getting locked by OS use MSI file for the installation.Collection Commander for Configuration Manager 2012: CMCollCtr 1.0.0: Change log: - MSI Setup - UI Improved - CM12 Console integration - New Powershell code snippets - Client Center IntegrationLINQ to Twitter: LINQ to Twitter v2.1.09: Supports .NET 3.5, .NET 4.0, .NET 4.5, Silverlight 4.0, Windows Phone 7.1, Windows Phone 8, Client Profile, Windows 8, and Windows Azure. 100% Twitter API coverage. Also supports Twitter API v1.1! Also on NuGet.Sandcastle Help File Builder: SHFB v1.9.8.0 with Visual Studio Package: General InformationIMPORTANT: On some systems, the content of the ZIP file is blocked and the installer may fail to run. Before extracting it, right click on the ZIP file, select Properties, and click on the Unblock button if it is present in the lower right corner of the General tab in the properties dialog. This new release contains bug fixes and feature enhancements. There are some potential breaking changes in this release as some features of the Help File Builder have been moved into...C++ REST SDK (codename "Casablanca"): C++ REST SDK 1.3.0: This release fixes multiple customer reported issues as well as the following: Full support for Dev12 binaries and project files Full support for Windows XP New sample highlighting the Client and Server APIs : BlackJack Expose underlying native handle to set custom options on http_client Improvements to Listener Library Note: Dev10 binaries have been dropped as of this release, however the Dev10 project files are still available in the Source CodeAD ACL Scanner: 1.3.2: Minor bug fixed: Powershell 4.0 will report: Select—Object: Parameter cannot be processed because the parameter name p is ambiguous.Fast YouTube Downloader: YouTube Downloader 2.2.0: YouTube Downloader 2.2.0VidCoder: 1.5.8 Beta: Added hardware acceleration options: Bicubic OpenCL scaling algorithm, QSV decoding/encoding and DXVA decoding. Updated HandBrake core to SVN 5834. Updated VidCoder setup icon. Fixed crash when choosing the mp4v2 container on x86 and opening on x64. Warning: the hardware acceleration features require specific hardware or file types to work correctly: QSV: Need an Intel processor that supports Quick Sync Video encoding, with a monitor hooked up to the Intel HD Graphics output and the lat...ASP.net MVC Awesome - jQuery Ajax Helpers: 3.5.2: version 3.5.2 - fix for setting single value to multivalue controls - datepicker min max date offset fix - html encoding for keys fix - enable Column.ClientFormatFunc to be a function call that will return a function version 3.5.1 - fixed html attributes rendering - fixed loading animation rendering - css improvements version 3.5 ========================== - autosize for all popups ( can be turned off by calling in js awe.autoSize = false ) - added Parent, Paremeter extensions ...New Projectsag2: ag2ApplicationMobile: ApplicationMobileBing Maps/Geolocalization Windows Store Template: Template de aplicativo para Windows 8 utilizando APIs do Bing Maps e Geolocalização. C3D.NET: C3D.NET is a free class library for manipulating C3D file. This project supports .NET 2.0 and .NET 4.0, and provides a free Data Viewer based on this library.DrinksMachineCMC: DrinksMachineCMCFerdeenFatalSpeech: Speech recognition for PC control.FuzzyLogic: FuzzyLogic Demohousekeeping: ?????isolutions Techdays 2013: Zeigt die Möglichkeit des Zugriffes auf ein CRM 2013 Online mit einer Windows Store App und aus einem Word Plugin.Learn .NET Gadgeteer: .NET Gadgeteer example projects using the FEZ Cerberus kit from GHILIT.Logger.ServerChecker: Small application for server monitoring, which demonstrates capabilities of LIT.Logger (www.litlogger.com)LuaTools for Visual Studio: luatools lua visual studioMTM Test Plan Viewer: A UI tool that lets you easily view, explore and export MTM test results.NetworkScan: Network scan windowsObservable Linq: Observable Linq and Observable Expressions is about to change the paradigm how to use expressions and Linq, providing update events whenever the results change.PatientManagement: beep beeppescar-shop-El-enchufe-khristo-grecia-giselle: falta la aplicacion de LINQ...ProjetoEscola: Projeto Integrado Senac Proyecto Librería PRISA: Este sistema servirá para controlar las compras, ventas y almacén de librería "PRISA". Se desarrollará en Visual Studio 2012 con patrón MVC y en base a capas.TDataBase: Simple db query libraryzongtest: test

    Read the article

  • How lookaheads are propagated in "channel" method of building LALR parser?

    - by greenoldman
    The method is described in Dragon Book, however I read about it in ""Parsing Techniques" by D.Grune and C.J.H.Jacobs". I start from my understanding of building channels for NFA: channels are built once, they are like water channels with current you "drop" lookahead symbols in right places (sources) of the channel, and they propagate with "current" when symbol propagates, there are no barriers (the only sufficient things for propagation are presence of channel and direction/current); i.e. lookahead cannot just die out of the blue Is that right? If I am correct, then eof lookahead should be present in all states, because the source of it is the start production, and all other production states are reachable from start state. How the DFA is made out of this NFA is not perfectly clear for me -- the authors of the mentioned book write about preserving channels, but I see no purpose, if you propagated lookaheads. If the channels have to be preserved, are they cut off from the source if the DFA state does not include source NFA state? I assume no -- the channels still runs between DFA states, not only within given DFA state. In the effect eof should still be present in all items in all states. But when you take a look at DFA presented in book (pdf is from errata): DFA for LALR (fig. 9.34 in the book, p.301) you will see there are items without eof in lookahead. The grammar for this DFA is: S -> E E -> E - T E -> T T -> ( E ) T -> n So how it was computed, when eof was dropped, and on what condition? Update It is textual pdf, so two interesting states (in DFA; # is eof): State 1: S--- >•E[#] E--- >•E-T[#-] E--- >•T[#-] T--- >•n[#-] T--- >•(E)[#-] State 6: T--- >(•E)[#-)] E--- >•E-T[-)] E--- >•T[-)] T--- >•n[-)] T--- >•(E)[-)] Arc from 1 to 6 is labeled (.

    Read the article

  • learn the programming language for computing functions about integers

    - by asd
    Hi I know something about Pascal, Mathematica and Matlab, but I dont have any idea about C,C++,C# languages. I want to learn one of the languages that they they are fast and exact to compute some arithmetic functions for large numbers(for example larger than $10^3000$). I asked somebody and he said he used C++ and he said I computed this sequence in less than 10 min. I want to know C, C++, C# and visual kind of theses programs and know which is better for my goal. Let $f$ be an arithmetic function and A={k1,k2,...,kn} are integers in increasing order. Now I want to start with k1 and compare f(ki) with f(k1). If f(ki)f(k1), put ki as k1. Now start with ki, and compare f(kj) with f(ki), for ji. If f(kj)f(ki), put kj as ki, and repeat this procedure. At the end we will have a sub sequence B={L1,...,Lm} of A by this property: f(L(i+1))f(L(i)), for any 1<=i<=m-1 I have written a code for this program with Mathematica, and it take some hours to compute f of ki's or the set B for large numbers. For example, let f is the divisor function of integers. Do you know how to write the code for my purpose in Mathematica or Matlab. Mathematica is preferable.

    Read the article

  • Using MVC with a retained mode renderer

    - by David Gouveia
    I am using a retained mode renderer similar to the display lists in Flash. In other words, I have a scene graph data structure called the Stage to which I add the graphical primitives I would like to see rendered, such as images, animations, text. For simplicity I'll refer to them as Sprites. Now I'm implementing an architecture which is becoming very similar to MVC, but I feel that that instead of having to create View classes, that the sprites already behave pretty much like Views (except for not being explicitly connected to the Model). And since the Model is only changed through the Controller, I could simply update the view together with the Model in the controller, as in the example below: Example 1 class Controller { Model model; Sprite view; void TeleportTo(Vector2 position) { model.Position = view.Position = position; } } The alternative, I think, would be to create View classes that wrap the sprites, make the model observable, and make the view react to changes on the model. This seems like a lot of extra work and boilerplate code, and I'm not seeing the benefits if I'm just going to have one view per controller. Example 2 class Controller { Model model; View view; void TeleportTo(Vector2 position) { model.Position = position; } } class View { Model model; Sprite sprite; View() { model.PropertyChanged += UpdateView; } void UpdateView() { sprite.Position = model.Position; } } So, how is MVC or more specifically, the View, usually implemented when using a retained-mode renderer? And is there any reason why I shouldn't stick with example 1?

    Read the article

  • Performing client-side OAuth authorized Twitter API calls versus server side, how much of a difference is there in terms of performance?

    - by Terence Ponce
    I'm working on a Twitter application in Ruby on Rails. One of the biggest arguments that I have with other people on the project is the method of calling the Twitter API. Before, everything was done on the server: OAuth login, updating the user's Twitter data, and retrieving tweets. Retrieving tweets was the heaviest thing to do since we don't store the tweets in our database, so viewing the tweets means that we have to call the API every time. One of the people in the project suggested that we call the tweets through Javascript instead to lessen the load on the server. We used GET search, which, correct me if I'm wrong, will be removed when v1.0 becomes completely deprecated, but that really isn't a concern now. When the Twitter API has migrated completely to v1.1 (again, correct me if I'm wrong), every calls to the API must be authenticated, so we have to authenticate our Javascript requests to the API. As said here: We don't support or recommend performing OAuth directly through Javascript -- it's insecure and puts your application at risk. The only acceptable way to perform it is if you kept all keys and secrets server-side, computed the OAuth signatures and parameters server side, then issued the request client-side from the server-generated OAuth values. If we do exactly what Twitter suggests, the only difference between this and doing everything server-side is that our server won't have to contact the Twitter API anymore every time the user wants to view tweets. Here's how I would picture what's happening every time the user makes a request: If we do it through Javascript, it would be harder on my part because I would have to create the signatures manually for every request, but I will gladly do it if the boost in performance is worth all the trouble. Doing it through Ruby on Rails would be very easy since the Twitter gem does most of the grunt work already, so I'm really encouraging the other people in the project to agree with me. Is the difference in performance trivial or is it significant enough to switch to Javascript?

    Read the article

  • Where to place the R code for R+Sweave+LaTeX workflow

    - by claytontstanley
    I spent the last week learning 3 new tools: R, Sweave, and LaTeX. One question that came to my mind though when working through my first project: Where do I place the majority of the R code? The tutorials that I read online placed the majority of the R code in the LaTeX .Rnw file. However, I find having a bunch of R calculations in the LaTeX file distracting. What I do find extremely helpful (of course) is to call out to R code in the LaTeX file and embed the result. So the workflow I've been using is to place 99% of my R code in my .R file. I run that file first, save a bunch of calculations as objects, and output the .Rout file once finished (to save the work). Then when running Sweave, I load up that .Rout file, so that I have the majority of my calculations already completed and in the Sweave R session. Then my LaTeX callouts to R are quite simple: Just give me the XTable stored in 'res.table', or give me the result of an already-computed calculation stored in the variable 'res'. So I push towards the minimal amount of R code in the LaTex file possible, to achieve the desired result (embedding stats results in the LaTeX writeup). Does anyone have any experience with this approach? I'm just worried I might run into trouble further down the line, when I start really trying to load up and leverage this workflow.

    Read the article

  • Where to put business logic in MVC design?

    - by BriskLabs Pakistan
    I have created a simple MVC java application that adds records through data forms to a database. my app collects data, it also validates it and stores it. This is because the data is being sourced online from different users. the data is mostly numeric in nature. now on the numeric data being stored into database (SQL server) , i wish that my app should be able to perform computations... and display it. the user is not interested in how computations are done so they must be encapsulated. the user must only be able to view the simple computed data which for example A column data - B Column data / C column data etc... and just display it to the user... i know how to write stored procedures for same but i want a 3 tier app I want the data, that I put into the database as a record, worked upon by performing calculations on it. However, the original data should remain unaffected, while the new data, post-calculations, must be stored as a new entity record into the database. Where should I write the code for this background calculation? As it is the rules and business logic... in a new java beans files ?

    Read the article

  • How to notify client about updated UpdatePanel content on server side

    - by csh1981
    I have a problem with UpdatePanel.Update() which works initially but then stops. I have tumbled with this problem for some time and some background is needed so please read ahead. I have an ASP.net application in which I have a subpage that display computed information in graphs. Each graph is embedded in an UpdatePanel. The graph is a user control that uses the standard asp:Chart for display. My task is to enable this page with AJAX capabilities so the page is responsive during postbacks. When I access this page from another page, during the initial page rendering, I use a wait dialog for each graph and a pageload event on the client side. In the client event, a hidden button is clicked which a server event handles (the hidden button is inside an UpdatePanel so the postback is asynchronous). Each graph is computed and the UpdatePanels are in turn updated with the Chart content. This is done using UpdatePanel.Update. And it is successful. However, I also have some RadioButtons on the page. These are dynamically created. The purpose of them is to switch graph type --- to show the same data in a different way. Same type of time consuming computation is needed in order to do so. I subscribe on each RadioButton's OnCheckedChanged event and the postback is asynchronous since the radiobuttons are inside an UpdatePanel. In the server event handler I determine the type of graph and use this as an input to the Chart control. I then remove the old Chart control from my Panel and adds new Chart and then I call UpdatePanel.Update(). But with no success. Nothing happens, no errors, nothing. Why is this?? I think this is strange because if I compute every Chart data in the initial rendering instead of using the "Wait dialog"-solution described earlier then I can select graph types successfully and all subsequent AJAX requests work as intended. Also, the same code (computing the chart, removal, and adding the Chart control to Panel and UpdatePanel.Update()) is hit during the initial rendering of the page, and it works only the first time. Here is the method that computes the graph and adds it to the panel and update the UpdatePanel: public void UpdateGraph(GraphType type, GraphMapper mapper) { //Panel is the content of UpdatePanelGraph's Panel.Controls.Clear(); chart = new Chart(type, mapper); //Computation happens inside here panel.Controls.Add(chart); //UpdatePanelGraph is in UpdateMode Conditional and has //ChildrenAsTriggers set to false UpdatePanelGraph.Update(); } I really need a way for these radiobuttons to work, possible using some clientside JavaScript or another way of handling things on the server side. I have thought about using a JavaScript postback call on the UpdatePanel instead of the UpdatePanel.Update(). However, the issue I have here is how to notify the client side when the server side is finished with computing the graph? An plausible explanation of the strange behavior is also much appreciated. Any help appreciated, thanks

    Read the article

  • XNA hlsl tex2D() only reads 3 channels from normal maps and specular maps

    - by cubrman
    Our engine uses deferred rendering and at the main draw phase gathers plenty of data from the objects it draws. In order to save on tex2D calls, we packed our objects' specular maps with all sorts of data, so three out of four channels are already taken. To make it clear: I am talking about the assets that come with the models and are stored in their material's Specular Level channel, not about the RenderTarget. So now I need another information to be stored in the alpha channel, but I cannot make the shader to read it properly! Nomatter what I write into alpha it ends up being 1 (255)! I tried: saving the textures in PNG/TGA formats. turning off pre-computed alpha in model's properties. Out of every texture available to me (we use Diffuse map, Normal Map and Specular Map) I was only able to read alpha successfully from the Diffuse Map! Here is how I add specular and normal maps to my model's material in the content processor: if (geometry.Material.Textures.ContainsKey(normalMapKey)) { ExternalReference<TextureContent> texRef = geometry.Material.Textures[normalMapKey]; geometry.Material.Textures.Remove("NormalMap"); geometry.Material.Textures.Add("NormalMap", texRef); } ... foreach (KeyValuePair<String, ExternalReference<TextureContent>> texture in material.Textures) { if ((texture.Key == "Texture") || (texture.Key == "NormalMap") || (texture.Key == "SpecularMap")) mat.Textures.Add(texture.Key, texture.Value); } In the shader I obviously use: float4 data = tex2D(specularMapSampler, TexCoords); so data.a is always 1 in my case, could you suggest a reason?

    Read the article

  • Japanese Multiplication simulation - is a program actually capable of improving calculation speed?

    - by jt0dd
    On SuperUser, I asked a (possibly silly) question about processors using mathematical shortcuts and would like to have a look at the possibility at the software application of that concept. I'd like to write a simulation of Japanese Multiplication to get benchmarks on large calculations utilizing the shortcut vs traditional CPU multiplication. I'm curious as to whether it makes sense to try this. My Question: I'd like to know whether or not a software math shortcut, as described above is actually a shortcut at all. This is a question of programming concept. By utilizing the simulation of Japanese Multiplication, is a program actually capable of improving calculation speed? Or am I doomed from the start? The answer to this question isn't required to determine whether or not the experiment will succeed, but rather whether or not it's logically possible for such a thing to occur in any program, using this concept as an example. My theory is that since addition is computed faster than multiplication, a simulation of Japanese multiplication may actually allow a program to multiply (large) numbers faster than the CPU arithmetic unit can. I think this would be a very interesting finding, if it proves to be true. If, in the multiplication of numbers of any immense size, the shortcut were to calculate the result via less instructions (or faster) than traditional ALU multiplication, I would consider the experiment a success.

    Read the article

  • Execution plan warnings–All that glitters is not gold

    - by Dave Ballantyne
    In a previous post, I showed you the new execution plan warnings related to implicit and explicit warnings.  Pretty much as soon as i hit ’post’,  I noticed something rather odd happening. This statement : select top(10) SalesOrderHeader.SalesOrderID, SalesOrderNumberfrom Sales.SalesOrderHeaderjoin Sales.SalesOrderDetail on SalesOrderHeader.SalesOrderID = SalesOrderDetail.SalesOrderID   Throws the “Type conversion may affect cardinality estimation” warning.     Ive done no such conversion in my statement why would that be ?  Well, SalesOrderNumber is a computed column , “(isnull(N'SO'+CONVERT([nvarchar](23),[SalesOrderID],0),N'*** ERROR ***'))”,  so thats where the conversion is.   Wait!!! Am i saying that every type conversion will throw the warning ?  Thankfully, no.  It only appears for columns that are used in predicates ,even if the predicate / join condition is fine ,  and the column is indexed ( and/or , presumably has statistics).    Hopefully , this wont lead to to many wild goose chases, but is definitely something to bear in mind.  If you want to see this fixed then upvote my connect item here.

    Read the article

  • Best Terminology for a particular php-based site architecture? [closed]

    - by hen3ry
    For a site... o whose overall look-and-feel is generated by one php page ("index.php"). o in which "index.php" provides for all pages served the following required components: The DOCTYPE, opening html tag, the head section, the opening body tag, the end-body tag, and end-html tag. o which uses computed hierarchical navigation menus within "index.php" to offer visitors access to the site content. o in which all content is stored in individual files that contain "headerless html". (The DOCTYPE, etc. etc. being being provided by "index.php" as described above.) Q1: what term best describes this architecture? I'm seeking a concise descriptor that is useful in conversation and definitive as a search term, in whole-web searches, and searching here on Pro Webmasters. Q2: what term best describes the individual content files? Same general goals for the descriptor as above. As you see above, I couldn't avoid using the term "headerless html", my best choice. But this term does not seem to be in general use. I've found some people use this term to describe such as my content files, but others use it quite differently.

    Read the article

  • Stumbling Through: Visual Studio 2010 (Part IV)

    So finally we get to the fun part the fruits of all of our middle-tier/back end labors of generating classes to interface with an XML data source that the previous posts were about can now be presented quickly and easily to an end user.  I think.  Well see.  Well be using a WPF window to display all of our various MFL information that weve collected in the two XML files, and well provide a means of adding, updating and deleting each of these entities using as little code as possible.  Additionally, I would like to dig into the performance of this solution as well as the flexibility of it if were were to modify the underlying XML schema.  So first things first, lets create a WPF project and include our xml data in a data folder within.  On the main window, well drag out the following controls: A combo box to contain all of the teams A list box to show the players of the selected team, along with add/delete player buttons A text box tied to the selected players name, with a save button to save any changes made to the player name A combo box of all the available positions, tied to the currently selected players position A data grid tied to the statistics of the currently selected player, with add/delete statistic buttons This monstrosity of a form and its associated project will look like this (dont forget to reference the DataFoundation project from the Presentation project): To get to the visual data binding, as we learned in a previous post, you have to first make sure the project containing your bindable classes is compiled.  Do so, and then open the Data Sources pane to add a reference to the Teams and Positions classes in the DataFoundation project: Why only Team and Position?  Well, we will get to Players from Teams, and Statistics from Players so no need to make an interface for them as well see in a second.  As for Positions, well need a way to bind the dropdown to ALL positions they dont appear underneath any of the other classes so we need to reference it directly.  After adding these guys, expand every node in your Data Sources pane and see how the Team node allows you to drill into Players and then Statistics.  This is why there was no need to bring in a reference to those classes for the UI we are designing: Now for the seriously hard work of binding all of our controls to the correct data sources.  Drag the following items from the Data Sources pane to the specified control on the window design canvas: Team.Name > Teams combo box Team.Players.Name > Players list box Team.Players.Name > Player name text box Team.Players.Statistics > Statistics data grid Position.Name > Positions combo box That is it!  Really?  Well, no, not really there is one caveat here in that the Positions combo box is not bound the selected players position.  To do so, we will apply a binding to the position combo boxs SelectedValue to point to the current players PositionId value: That should do the trick now, all we need to worry about is loading the actual data.  Sadly, it appears as if we will need to drop to code in order to invoke our IO methods to load all teams and positions.  At least Visual Studio kindly created the stubs for us to do so, ultimately the code should look like this: Note the weirdness with the InitializeDataFiles call that is my current means of telling an IO where to load the data for each of the entities.  I havent thought of a more intuitive way than that yet, but do note that all data is loaded from Teams.xml besides for positions, which is loaded from Lookups.xml.   I think that may be all we need to do to at least load all of the data, lets run it and see: Yay!  All of our glorious data is being displayed!  Er, wait, whats up with the position dropdown?  Why is it red?  Lets select the RB and see if everything updates: Crap, the position didnt update to reflect the selected player, but everything else did.  Where did we go wrong in binding the position to the selected player?  Thinking about it a bit and comparing it to how traditional data binding works, I realize that we never set the value member (or some similar property) to tell the control to join the Id of the source (positions) to the position Id of the player.  I dont see a similar property to that on the combo box control, but I do see a property named SelectedValuePath that might be it, so I set it to Id and run the app again: Hey, all right!  No red box around the positions combo box.  Unfortunately, selecting the RB does not update the dropdown to point to Runningback.  Hmmm.  Now what could it be?  Maybe the problem is that we are loading teams before we are loading positions, so when it binds position Id, all of the positions arent loaded yet.  I went to the code behind and switched things so position loads first and no dice.  Same result when I run.  Why?  WHY?  Ok, ok, calm down, take a deep breath.  Get something with caffeine or sugar (preferably both) and think rationally. Ok, gigantic chocolate chip cookie and a mountain dew chaser have never let me down in the past, so dont fail me now!  Ah ha!  of course!  I didnt even have to finish the mountain dew and I think Ive got it:  Data Context.  By default, when setting on the selected value binding for the dropdown, the data context was list_team.  I dont even know what the heck list_team is, we want it to be bound to our team players view source resource instead, like this: Running it now and selecting the various players: Done and done.  Everything read and bound, thank you caffeine and sugar!  Oh, and thank you Visual Studio 2010.  Lets wire up some of those buttons now There has got to be a better way to do this, but it works for now.  What the add player button does is add a new player object to the currently selected team.  Unfortunately, I couldnt get the new object to automatically show up in the players list (something about not using an observable collection gotta look into this) so I just save the change immediately and reload the screen.  Terrible, but it works: Lets go after something easier:  The save button.  By default, as we type in new text for the players name, it is showing up in the list box as updated.  Cool!  Why couldnt my add new player logic do that?  Anyway, the save button should be as simple as invoking MFL.IO.Save for the selected player, like this: MFL.IO.Save((MFL.Player)lbTeamPlayers.SelectedItem, true); Surprisingly, that worked on the first try.  Lets see if we get as lucky with the Delete player button: MFL.IO.Delete((MFL.Player)lbTeamPlayers.SelectedItem); Refresh(); Note the use of the Refresh method again I cant seem to figure out why updates to the underlying data source are immediately reflected, but adds and deletes are not.  That is a problem for another day, and again my hunch is that I should be binding to something more complex than IEnumerable (like observable collection). Now that an example of the basic CRUD methods are wired up, I want to quickly investigate the performance of this beast.  Im going to make a special button to add 30 teams, each with 50 players and 10 seasons worth of stats.  If my math is right, that will end up with 15000 rows of data, a pretty hefty amount for an XML file.  The save of all this new data took a little over a minute, but that is acceptable because we wouldnt typically be saving batches of 15k records, and the resulting XML file size is a little over a megabyte.  Not huge, but big enough to see some read performance numbers or so I thought.  It reads this file and renders the first team in under a second.  That is unbelievable, but we are lazy loading and the file really wasnt that big.  I will increase it to 50 teams with 100 players and 20 seasons each - 100,000 rows.  It took a year and a half to save all of that data, and resulted in an 8 megabyte file.  Seriously, if you are loading XML files this large, get a freaking database!  Despite this, it STILL takes under a second to load and render the first team, which is interesting mostly because I thought that it was loading that entire 8 MB XML file behind the scenes.  I have to say that I am quite impressed with the performance of the LINQ to XML approach, particularly since I took no efforts to optimize any of this code and was fairly new to the concept from the start.  There might be some merit to this little project after all Look out SQL Server and Oracle, use XML files instead!  Next up, I am going to completely pull the rug out from under the UI and change a number of entities in our model.  How well will the code be regenerated?  How much effort will be required to tie things back together in the UI?Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • Java code optimization leads to numerical inaccuracies and errors

    - by rano
    I'm trying to implement a version of the Fuzzy C-Means algorithm in Java and I'm trying to do some optimization by computing just once everything that can be computed just once. This is an iterative algorithm and regarding the updating of a matrix, the clusters x pixels membership matrix U, this is the update rule I want to optimize: where the x are the element of a matrix X (pixels x features) and v belongs to the matrix V (clusters x features). And m is a parameter that ranges from 1.1 to infinity. The distance used is the euclidean norm. If I had to implement this formula in a banal way I'd do: for(int i = 0; i < X.length; i++) { int count = 0; for(int j = 0; j < V.length; j++) { double num = D[i][j]; double sumTerms = 0; for(int k = 0; k < V.length; k++) { double thisDistance = D[i][k]; sumTerms += Math.pow(num / thisDistance, (1.0 / (m - 1.0))); } U[i][j] = (float) (1f / sumTerms); } } In this way some optimization is already done, I precomputed all the possible squared distances between X and V and stored them in a matrix D but that is not enough, since I'm cycling througn the elements of V two times resulting in two nested loops. Looking at the formula the numerator of the fraction is independent of the sum so I can compute numerator and denominator independently and the denominator can be computed just once for each pixel. So I came to a solution like this: int nClusters = V.length; double exp = (1.0 / (m - 1.0)); for(int i = 0; i < X.length; i++) { int count = 0; for(int j = 0; j < nClusters; j++) { double distance = D[i][j]; double denominator = D[i][nClusters]; double numerator = Math.pow(distance, exp); U[i][j] = (float) (1f / (numerator * denominator)); } } Where I precomputed the denominator into an additional column of the matrix D while I was computing the distances: for (int i = 0; i < X.length; i++) { for (int j = 0; j < V.length; j++) { double sum = 0; for (int k = 0; k < nDims; k++) { final double d = X[i][k] - V[j][k]; sum += d * d; } D[i][j] = sum; D[i][B.length] += Math.pow(1 / D[i][j], exp); } } By doing so I encounter numerical differences between the 'banal' computation and the second one that leads to different numerical value in U (not in the first iterates but soon enough). I guess that the problem is that exponentiate very small numbers to high values (the elements of U can range from 0.0 to 1.0 and exp , for m = 1.1, is 10) leads to ver y small values, whereas by dividing the numerator and the denominator and THEN exponentiating the result seems to be better numerically. The problem is it involves much more operations. Am I doing something wrong? Is there a possible solution to get both the code optimized and numerically stable? Any suggestion or criticism will be appreciated.

    Read the article

  • snapping an angle to the closest cardinal direction

    - by Josh E
    I'm developing a 2D sprite-based game, and I'm finding that I'm having trouble with making the sprites rotate correctly. In a nutshell, I've got spritesheets for each of 5 directions (the other 3 come from just flipping the sprite horizontally), and I need to clamp the velocity/rotation of the sprite to one of those directions. My sprite class has a pre-computed list of radians corresponding to the cardinal directions like this: protected readonly List<float> CardinalDirections = new List<float> { MathHelper.PiOver4, MathHelper.PiOver2, MathHelper.PiOver2 + MathHelper.PiOver4, MathHelper.Pi, -MathHelper.PiOver4, -MathHelper.PiOver2, -MathHelper.PiOver2 + -MathHelper.PiOver4, -MathHelper.Pi, }; Here's the positional update code: if (velocity == Vector2.Zero) return; var rot = ((float)Math.Atan2(velocity.Y, velocity.X)); TurretRotation = SnapPositionToGrid(rot); var snappedX = (float)Math.Cos(TurretRotation); var snappedY = (float)Math.Sin(TurretRotation); var rotVector = new Vector2(snappedX, snappedY); velocity *= rotVector; //...snip private float SnapPositionToGrid(float rotationToSnap) { if (rotationToSnap == 0) return 0.0f; var targetRotation = CardinalDirections.First(x => (x - rotationToSnap >= -0.01 && x - rotationToSnap <= 0.01)); return (float)Math.Round(targetRotation, 3); } What am I doing wrong here? I know that the SnapPositionToGrid method is far from what it needs to be - the .First(..) call is on purpose so that it throws on no match, but I have no idea how I would go about accomplishing this, and unfortunately, Google hasn't helped too much either. Am I thinking about this the wrong way, or is the answer staring at me in the face?

    Read the article

  • Mouse Speed in GLUT and OpenGL?

    - by CroCo
    I would like to simulate a point that moves in 2D. The input should be the speed of the mouse, so the new position will be computed as following new_position = old_position + delta_time*mouse_velocity As far as I know in GLUT there is no function to acquire the current speed of the mouse between each frame. What I've done so far to compute the delta_time as following void Display() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glColor3f(1.0f, 0.0f, 0.0f); static int delta_t, current_t, previous_t; current_t = glutGet(GLUT_ELAPSED_TIME); delta_t = current_t - previous_t; std::cout << delta_t << std::endl; previous_t = current_t; glutSwapBuffers(); } Where should I start from here? (Note: I have to get the speed of the mouse because I'm modeling a system) Edit: Based on the above code, delta_time fluctuates so much 34 19 2 20 1 20 0 16 1 1 10 21 0 13 1 19 34 0 13 0 6 1 14 Why does this happen?

    Read the article

  • Creating movement path displays in a top-down 2d RTS

    - by nihohit
    My game is a top-down 2d RTS coded in C# using SFML's libraries. I want that during unit selection, a unit will display it's movement path on the map. Currently, after the path is computed as a list of directions ({left, up,down, down, down, left}, as an example), it's sent to the graphical component to create it's UI equivalent, and here I'm having some problems. current, these I've checked three ways to do it: compute the size of the image (in the example above it'll be a 3*2 rectangle) and create an invisible rectangle, and then go over the directions list and mark each spot with a visible point, so as to get a continous line. This system is slightly problematic because of the amount of large images that I need to save, but mostly because I have a lot of fine detail onscreen, and a continous line obstructs the view. again, compute the size of the image, but now create several (let's say 4) invisible images of that size, and then instead of a single continous line I'll switch between the four images, in each will appear only a fourth of the spots, in a way which creates a path animation. This is nicer on the eye, but here the memory demands, and the amount of time needed to compute each such image-loop is significant. Just create a list of single markers, each on a different spot on the path. This is very quick & easy on memory, but too sparse. Is there a simple or resource-light system to create path-animations?

    Read the article

  • Simplifying data search using .NET

    - by Peter
    An example on the asp.net site has an example of using Linq to create a search feature on a Music album site using MVC. The code looks like this - public ActionResult Index(string movieGenre, string searchString) { var GenreLst = new List<string>(); var GenreQry = from d in db.Movies orderby d.Genre select d.Genre; GenreLst.AddRange(GenreQry.Distinct()); ViewBag.movieGenre = new SelectList(GenreLst); var movies = from m in db.Movies select m; if (!String.IsNullOrEmpty(searchString)) { movies = movies.Where(s => s.Title.Contains(searchString)); } if (!string.IsNullOrEmpty(movieGenre)) { movies = movies.Where(x => x.Genre == movieGenre); } return View(movies); } I have seen similar examples in other tutorials and I have tried them in a real-world business app that I develop/maintain. In practice this pattern doesn't seem to scale well because as the search criteria expands I keep adding more and more conditions which looks and feels unpleasant/repetitive. How can I refactor this pattern? One idea I have is to create a column in every table that is "searchable" which could be a computed column that concatenates all the data from the different columns (SQL Server 2008). So instead of having movie genre and title it would be something like. if (!String.IsNullOrEmpty(searchString)) { movies = movies.Where(s => s.SearchColumn.Contains(searchString)); } What are the performance/design/architecture implications of doing this? I have also tried using procedures that use dynamic queries but then I have just moved the ugliness to the database. E.g. CREATE PROCEDURE [dbo].[search_music] @title as varchar(50), @genre as varchar(50) AS -- set the variables to null if they are empty IF @title = '' SET @title = null IF @genre = '' SET @genre = null SELECT m.* FROM view_Music as m WHERE (title = @title OR @title IS NULL) AND (genre LIKE '%' + @genre + '%' OR @genre IS NULL) ORDER BY Id desc OPTION (RECOMPILE) Any suggestions? Tips?

    Read the article

  • Context switches much slower in new linux kernels

    - by Michael Goldshteyn
    We are looking to upgrade the OS on our servers from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS. Unfortunately, it seems that the latency to run a thread that has become runnable has significantly increased from the 2.6 kernel to the 3.2 kernel. In fact the latency numbers we are getting are hard to believe. Let me be more specific about the test. We have a program that has two threads. The first thread gets the current time (in ticks using RDTSC) and then signals a condition variable once a second. The second thread waits on the condition variable and wakes up when it is signaled. It then gets the current time (in ticks using RDTSC). The difference between the time in the second thread and the time in the first thread is computed and displayed on the console. After this the second thread waits on the condition variable once more. So, we get a thread to thread signaling latency measurement once a second as a result. In linux 2.6.32, this latency is somewhere on the order of 2.8-3.5 us, which is reasonable. In linux 3.2.0, this latency is somewhere on the order of 40-100 us. I have excluded any differences in hardware between the two host hosts. They run on identical hardware (dual socket X5687 {Westmere-EP} processors running at 3.6 GHz with hyperthreading, speedstep and all C states turned off). We are changing the affinity to run both threads on physical cores of the same socket (i.e., the first thread is run on Core 0 and the second thread is run on Core 1), so there is no bouncing of threads on cores or bouncing/communication between sockets. The only difference between the two hosts is that one is running Ubuntu 10.04 LTS with kernel 2.6.32-28 (the fast context switch box) and the other is running the latest Ubuntu 12.04 LTS with kernel 3.2.0-23 (the slow context switch box). Have there been any changes in the kernel that could account for this ridiculous slow down in how long it takes for a thread to be scheduled to run?

    Read the article

  • Is it possible/likely to be paid fairly without a college degree? [closed]

    - by user20134
    Some back story, and then my question: I took a "break" from getting a university education last year to work full time as back end developer on a GIS application at $10.50 an hour. Later that year I was hired on by a fairly prestigious organization on their GIS application for a meager salary + rockin' benefits (not that I need them). I agreed to work on this project through Summer 2012. I don't feel like I'm being fairly compensated for my time. Other team members make between 3-5 times as much as I do, and their work isn't 3-5 times as good as mine, nor do they have 3-5 times as much output. I don't think this is a rectifiable situation within this institution. They've got a set of personnel charts and the way it gets computed, I make less money than any of the janitors (who are very good, and very nice people to boot, and I'm glad they get paid so well. I wish everyone got livable wages). I'm pretty bright, but school's a drag. I don't want mega bucks, I just want $40k/yr (localized to the southeast united states) so I can save enough money to travel, or maybe "finish [my] education". My question is this: Are people without degrees ever compensated commensurate with other people who have degrees? As a someone who never "finished their education", how badly do you think this as hurt you? How do you navigate the job seeking and hiring process? As someone who hires programmers, do you pay more for diplomas? Is that an institutional necessity, or based on your own value judgement?

    Read the article

< Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18  | Next Page >