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  • Arrive steering behavior

    - by dbostream
    I bought a book called Programming game AI by example and I am trying to implement the arrive steering behavior. The problem I am having is that my objects oscillate around the target position; after oscillating less and less for awhile they finally come to a stop at the target position. Does anyone have any idea why this oscillating behavior occur? Since the examples accompanying the book are written in C++ I had to rewrite the code into C#. Below is the relevant parts of the steering behavior: private enum Deceleration { Fast = 1, Normal = 2, Slow = 3 } public MovingEntity Entity { get; private set; } public Vector2 SteeringForce { get; private set; } public Vector2 Target { get; set; } public Vector2 Calculate() { SteeringForce.Zero(); SteeringForce = SumForces(); SteeringForce.Truncate(Entity.MaxForce); return SteeringForce; } private Vector2 SumForces() { Vector2 force = new Vector2(); if (Activated(BehaviorTypes.Arrive)) { force += Arrive(Target, Deceleration.Slow); if (!AccumulateForce(force)) return SteeringForce; } return SteeringForce; } private Vector2 Arrive(Vector2 target, Deceleration deceleration) { Vector2 toTarget = target - Entity.Position; double distance = toTarget.Length(); if (distance > 0) { //because Deceleration is enumerated as an int, this value is required //to provide fine tweaking of the deceleration.. double decelerationTweaker = 0.3; double speed = distance / ((double)deceleration * decelerationTweaker); speed = Math.Min(speed, Entity.MaxSpeed); Vector2 desiredVelocity = toTarget * speed / distance; return desiredVelocity - Entity.Velocity; } return new Vector2(); } private bool AccumulateForce(Vector2 forceToAdd) { double magnitudeRemaining = Entity.MaxForce - SteeringForce.Length(); if (magnitudeRemaining <= 0) return false; double magnitudeToAdd = forceToAdd.Length(); if (magnitudeToAdd > magnitudeRemaining) magnitudeToAdd = magnitudeRemaining; SteeringForce += Vector2.NormalizeRet(forceToAdd) * magnitudeToAdd; return true; } This is the update method of my objects: public void Update(double deltaTime) { Vector2 steeringForce = Steering.Calculate(); Vector2 acceleration = steeringForce / Mass; Velocity = Velocity + acceleration * deltaTime; Velocity.Truncate(MaxSpeed); Position = Position + Velocity * deltaTime; } If you want to see the problem with your own eyes you can download a minimal example here. Thanks in advance.

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  • Dual monitor in Ubuntu 12.04 + Nvidia GPU with CUDA drivers?

    - by Aphex
    I'm thinking about setting up dual monitors on my desktop PC, running Ubuntu 12.04 with a Nvidia GTX 570. I use the GPU for CUDA programming so it's set up with the CUDA drivers. Is it possible/easy to set up dual monitors with this configuration? The only questions I saw related to this were for GPUs without cuda drivers. If anyone knows how dual monitors work with CUDA drivers, it would be much appreciated. It was enough of a pain getting everything running with the GPU and CUDA in the first place, I'd hate to ruin it all by attempting dual monitors.

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  • Android Touch Event Collision Detection

    - by chrissb
    I'm relatively new to both Java and Android, so hopefully the problem I'm having is stemming from something pretty minor that I've overlooked. I've got a (very early stage) game that I've started working on, for Android using Java. At this stage, when the user touches the screen, if they touched a point at which there is an enemy, the enemies health is decreased and they become immobile (for the current implementation at least). The issue that I'm having is that the touch detection doesn't always seem to work. I've got a testing sprite set up that goes to the eventX and eventY coordinates of the touch down event, and it always seems to collide with the enemy object. Yet, the enemy doesn't always register as being hit, and sometimes a hit is registered when the sprite indicates the touch coordinates were outside of the enemies bounding box. I realise that this probably doesn't mean much without any code, so here's what I've got so far. Be gentle, as this is literally my first attempt at something more than basic movement etc. First off, the MainGamePanel class registers the touch event, and informs the levelmanager class (which is what I set up to monitor/handle enemies) public boolean onTouchEvent(MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_DOWN){ levelManager.handleActionDown((int)event.getX(), (int)event.getY()); targetX=event.getX(); targetY=event.getY(); } if (event.getAction() == MotionEvent.ACTION_MOVE) { //the gestures } if (event.getAction() == MotionEvent.ACTION_UP) { //touch was released } return true; } From there, in the levelmanager class the touch event is passed on to all of the enemies within a list array: public static void handleActionDown(int eventX,int eventY){ hit=false; for (enemy1 en : enemy1array){ en.handleActionDown(eventX, eventY); } } The rest of the collision code is handled within the enemies handleActionDown function: public void handleActionDown(int eventX, int eventY) { if(eventX>this.x-enemy1bitmap.getWidth() && eventX<this.x+enemy1bitmap.getWidth() && eventY>this.y-enemy1bitmap.getHeight() && eventY<this.x+enemy1bitmap.getHeight()){ takeDamage(1); levelmanager.setHit(); } } I should probably be using getWidth()/2 and getHeight()/2 for it to be more accurate, but I expanded the area to test this - although I've noticed no improvement. At this stage, the games detection over whether or not the enemy is hit is spotty at best. Generally it takes two or three attempts before a collision is successfully registered, even though the sprite that is being used for testing and set to the eventX and eventY coordinates always indicates that the collision should have worked. Hopefully someone can steer me in the right direction here, and if more information is needed, ask away! Cheers, -Chris

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  • Appropriate level of granularity for component-based architecture

    - by Jon Purdy
    I'm working on a game with a component-based architecture. An Entity owns a set of Component instances, each of which has a set of Slot instances with which to store, send, and receive values. Factory functions such as Player produce entities with the required components and slot connections. I'm trying to determine the best level of granularity for components. For example, right now Position, Velocity, and Acceleration are all separate components, connected in series. Velocity and Acceleration could easily be rewritten into a uniform Delta component, or Position, Velocity, and Acceleration could be combined alongside such components as Friction and Gravity into a monolithic Physics component. Should a component have the smallest responsibility possible (at the cost of lots of interconnectivity) or should related components be combined into monolithic ones (at the cost of flexibility)? I'm leaning toward the former, but I could use a second opinion.

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  • Oracle ??????????? -2012?4??: Composite Patches

    - by James Zhang
      ???????DBA?????????????bundle patches, ??Patch Set Updates(PSU)????????,??oracle??????bundle patches,??PSU,??,??????????????,???????????????????(one-off patch),????overlay patches,???????????????   Oracle?????????,???2012?4???Database PSU 11.2.0.3.2??,??????patch??Composite Patches. Composite Patches ??:    * ?????    * ?????????overlay patches???    ?????????composite patches??,???????????????:Patch Set Update : ??????Cumulative patch(????),????, EM ??????????????????Patch Conflict   : 2??????????????,???????????Cumulative Patch : ????????,?????bug???,????Cumulative Patch?????????Cumulative PatchInterim Patch    : ???????????????Overlay Patch    : ?????????????,????????,????PSU???? ?merge patch??Sub-patch        : ??composite patch??2?????sub-patches?? ???Composite Patches?Composite Patches?????????,???????cumulative patch????composite patch?????Composite Patch?????????????. Composite Patches????????,Composite Patches???PSU??Bundle Patch????????????????????Composite Patches,???Composite Patches??????patch???????????Composite Patches,?????????Composite Patches???????????patches?????????overlay patches?Composite Patches???,???????overlay patches,???????,????overlay patches,???????????Composite Patches??overlay patches. cumulative patch?composite patch??????:* Cumulative Patch1.????Cumulative Patch?,??????????Cumulative Patch.2.???????overlay patches,?????overlay patches,??overlay patches?????cumulative patch??,???????cumulative patch??overlay patches,??????cumulative patch???overlay patches* Composite Patch1.???????????composite Patch,?????????Composite Patches??????2.???????overlay patches???cumulative patch???,???????overlay patches,??????cumulative patch. ????,?????overlay patches,??????cumulative patch??overlay patches? ???????????sub-patches??composite patch????????overlay patches* 11.2.0.3.1, 11.2.0.3.2, 11.2.0.3.3, 11.2.0.3.4 (??????) ??composite patch 11.2.0.3.4(?????)????(sub-patches)?????composite patch?,??sub-patches?????,?????????Composite Patch?????????????,??composite patch??????? * Overlay patches?composite patch(????) ???,?????overlay patch,????????composite patch????overly patch * ???11.2.0.3.4 ?,Overlay patches?composite patch(??????????)??,?????overlay patch,?????11.2.0.3.4 ??overlay patches,????11.2.0.3.4???overaly patches? ???PSU 11.2.0.3.2??????composite??????PSU, ?????composite patch?????,?????????newletter???????????,??????????:    Video - Bundle Patch Improvement - Composite Patching (03:43) [Trouble seeing this video?]    * Note 1376691.1 Composite Patches for Oracle Products (includes the brief informative video above)    * Note 854428.1   Patch Set Updates for Oracle Products    * Note 1299688.1 Patch conflict resolution    * Note 1321267.1 Database Patch conflict resolution

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  • How to insert countdown into a video file

    - by student
    Is there an easy way to insert a big countdown clock after a given time position of a video file in linux? The countdown clock should count down in seconds from n to 0. Edit: I don't want to insert manually pictures showing the nth second. It is clear to me how to do that. What I want is an automatic way to do this: Set the number of seconds for the countdown (e.g. 64 or 80 seconds) Set the time where to insert the countdown in a given video And finally get the video with inserted countdown at specified position as a result. It would be nice if this would be possible in a graphical video editor like openshot. However it would also be ok to have a command line solution for this.

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  • How do I cancel a time-delayed screenshot?

    - by coversnail
    I'm using the default screenshot application that comes with Ubuntu gnome-screenshot When I was using it earlier to take screenshots of the lock screen I had set a long time delay, but forgot to change it back after I'd finished. When I next took a timed screenshot I had to wait a long time for it to take because the delay was still set so long. Clicking the icon to relaunch the screenshot application has no effect whilst the timer is in effect, I imagine there is probably a simple terminal command to shut down an application, but I don't know it! Is there a way to do this?

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  • CodePlex Daily Summary for Sunday, June 16, 2013

    CodePlex Daily Summary for Sunday, June 16, 2013Popular ReleasesEmployee Info Starter Kit: v6.0 - ASP.NET MVC Edition: Release Home - Getting Started - Hands on Coding Walkthrough – Technology Stack - Design & Architecture EISK v6.0 – ASP.NET MVC edition bundles most of the greatest and successful platforms, frameworks and technologies together, to enable web developers to learn and build manageable and high performance web applications with rich user experience effectively and quickly. User End SpecificationsCreating a new employee record Read existing employee records Update an existing employee reco...OLAP PivotTable Extensions: Release 0.8.1: Use the 32-bit download for... Excel 2007 Excel 2010 32-bit (even Excel 2010 32-bit on a 64-bit operating system) Excel 2013 32-bit (even Excel 2013 32-bit on a 64-bit operating system) Use the 64-bit download for... Excel 2010 64-bit Excel 2013 64-bit Just download and run the EXE. There is no need to uninstall the previous release. If you have problems getting the add-in to work, see the Troubleshooting Installation wiki page. The new features in this release are: View #VALUE! Err...VidCoder: 1.4.22: New in 1.4.22 Added Xbox 360 preset, thanks to Relhak. Added Spanish translation, thanks to fantasmanegro. Added Basque translation, thanks to azpidatziak. Fixed behavior of custom anamorphic auto display width and max width/height. Fixed double-logging on local encodes. Fixed remote encoder not using libdvdnav even when enabled, which had caused some problems with multi-angle DVDs. New in 1.4 Updated HandBrake core to 0.9.9 Blu-ray subtitle (PGS) support Additional framerates: 30...WPF Application Framework (WAF): WPF Application Framework (WAF) 3.0.0.440: Version: 3.0.0.440 (Release Candidate): This release contains the source code of the WPF Application Framework (WAF) and the sample applications. Please build the whole solution before you start one of the sample applications. Requirements .NET Framework 4.5 (The package contains a solution file for Visual Studio 2012) Changelog Legend: [B] Breaking change; [O] Marked member as obsolete Samples: Use ValueConverters via StaticResource instead of x:Static. Other Downloads Downloads OverviewSFDL.NET: SFDL.NET v1.1.0.5: Changelog: Implemeted SFDL Container v4 (AES Encryption, Set Character Set) Added Stopwatch (download time) Many Bugfixes and ImprovementsBlackJumboDog: Ver5.9.1: 2013.06.13 Ver5.9.1 (1) Web??????SSI?#include???、CGI?????????????????????? (2) ???????????????????????????Lakana - WPF Framework: Lakana V2.1 RTM: - Dynamic text localization - A new application wide message busFree language translator and file converter: Free Language Translator 3.3: some bug fixes and a new link to video tutorials on Youtube.Pokemon Battle Online: ETV: ETV???2012?12??????,????,???????$/PBO/branches/PrivateBeta??。 ???????bug???????。 ???? Server??????,?????。 ?????????,?????????????,?????????。 ????????,????,?????????,???????????(??)??。 ???? ????????????。 ???????。 ???PP????,????????????????????PP????,??3。 ?????????????,??????????。 ???????? ??? ?? ???? ??? ???? ?? ?????????? ?? ??? ??? ??? ???????? ???? ???? ???????????????、???????????,??“???????”??。 ???bug ???Modern UI for WPF: Modern UI 1.0.4: The ModernUI assembly including a demo app demonstrating the various features of Modern UI for WPF. Related downloads NuGet ModernUI for WPF is also available as NuGet package in the NuGet gallery, id: ModernUI.WPF Download Modern UI for WPF Templates A Visual Studio 2012 extension containing a collection of project and item templates for Modern UI for WPF. The extension includes the ModernUI.WPF NuGet package. DownloadToolbox for Dynamics CRM 2011: XrmToolBox (v1.2013.6.11): XrmToolbox improvement Add exception handling when loading plugins Updated information panel for displaying two lines of text Tools improvementMetadata Document Generator (v1.2013.6.10)New tool Web Resources Manager (v1.2013.6.11)Retrieve list of unused web resources Retrieve web resources from a solution All tools listAccess Checker (v1.2013.2.5) Attribute Bulk Updater (v1.2013.1.17) FetchXml Tester (v1.2013.3.4) Iconator (v1.2013.1.17) Metadata Document Generator (v1.2013.6.10) Privilege...Document.Editor: 2013.23: What's new for Document.Editor 2013.23: New Insert Emoticon support Improved Format support Minor Bug Fix's, improvements and speed upsChristoc's DotNetNuke Module Development Template: DotNetNuke 7 Project Templates V2.4 for VS2012: V2.4 - Release Date 6/10/2013 Items addressed in this 2.4 release Updated MSBuild Community Tasks reference to 1.4.0.61 Setting up your DotNetNuke Module Development Environment Installing Christoc's DotNetNuke Module Development Templates Customizing the latest DotNetNuke Module Development Project TemplatesLayered Architecture Sample for .NET: Leave Sample - June 2013 (for .NET 4.5): Thank You for downloading Layered Architecture Sample. Please read the accompanying README.txt file for setup and installation instructions. This is the first set of a series of revised samples that will be released to illustrate the layered architecture design pattern. This version is only supported on Visual Studio 2012. This set contains 2 samples that illustrates the use of: ASP.NET Web Forms, ASP.NET Model Binding, Windows Communications Foundation (WCF), Windows Workflow Foundation (W...Papercut: Papercut 2013-6-10: Feature: Shows From, To, Date and Subject of Email. Feature: Async UI and loading spinner. Enhancement: Improved speed when loading large attachments. Enhancement: Decoupled SMTP server into secondary assembly. Enhancement: Upgraded to .NET v4. Fix: Messages lost when received very fast. Fix: Email encoding issues on display/Automatically detect message Encoding Installation Note:Installation is copy and paste. Incoming messages are written to the start-up directory of Papercut. If you do n...Supporting Guidance and Whitepapers: v1.BETA Unit test Generator Documentation: Welcome to the Unit Test Generator Once you’ve moved to Visual Studio 2012, what’s a dev to do without the Create Unit Tests feature? Based on the high demand on User Voice for this feature to be restored, the Visual Studio ALM Rangers have introduced the Unit Test Generator Visual Studio Extension. The extension adds the “create unit test” feature back, with a focus on automating project creation, adding references and generating stubs, extensibility, and targeting of multiple test framewor...MapWindow 4: MapWindow GIS v4.8.8 - Release Candidate - 32Bit: Download the release notes here: http://svn.mapwindow.org/svnroot/MapWindow4Dev/Bin/MapWindowNotes.rtfLINQ to Twitter: LINQ to Twitter v2.1.06: 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.VR Player: VR Player 0.3.1 ALPHA: New plugin system with individual folders TrackIR support Maya and 3ds max formats support Dual screen support Mono layouts (left and right) Cylinder height parameter Barel effect factor parameter Razer hydra filter parameter VRPN bug fixes UI improvements Performances improvements Stabilization and logging with Log4Net New default values base on users feedback CTRL key to open menuSimCityPak: SimCityPak 0.1.0.8: SimCityPak 0.1.0.8 New features: Import BMP color palettes for vehicles Import RASTER file (uncompressed 8.8.8.8 DDS files) View different channels of RASTER files or preview of all layers combined Find text in javascripts TGA viewer Ground textures added to lot editor Many additional identified instances and propertiesNew ProjectsADJD-S311-CR99 Colour Sensor Arduino: Integrating the Avago ADJD-s311-CR999 with ArduinoBerkeley Algorithm: student project for DS course Berkeley Algorithm C#Code Kata - HarryPotter Win8: HarryPotter Series discount programming excerciseHad CMS: Had CMSjean0615mercurialmm: ddjet.version.Incrementor: It's a console tool parse AssemblyInfo.cs files in given directory and set AssemblyVersion and AssemblyFileVersion attribtes to given version. It can be easilyLogger - logging for your .NET project using file, mail, debug output: A light weight yet competent logger for .NET with configurable output modules, such as log file, e-mail and debug log. Easy to add your own output module if needed.MatUtils: Um projecto onde se incluem algumas ferramentas matemáticas.MoGo Mobile: The first makings of an open source Mobile Game!myFirstHTML5: Project was to create a mobile responsive websiteNeTools: This Tool Allows You To Know & Monitor Your Network Better. You'l Be Able To Hijack The Network's Traffic, Poison The Network, Kick Devices From It & Many More.Prism Photo Browser: This is a functioning photo browser written in C# for a WPF platform implementing the Model View View-Model (MVVM) design pattern and PrismQuesTime: This is a quiz projectSM130 Arduino Integration: A project to integrate an SM130 RFID module with Arduino.SQL Server Analysis Services Cube Status Web Part for SharePoint: The Cube Status project provides a SharePoint Web Part that connects to a SQL Server Analysis Services instance and shows the status of a specific cubeSQLite Sync for Windows Phone 8: Project Description This project is the Windows Phone 8 implementation of the Sync Framework Toolkit to enable synchronization with Windows Phone 8 and SQLite.Test Project: testTool To Recover or Restore Windows 7 Files: Impossible Is Nothing!: Get easy to use Windows 2007 Recovery software which is fully helpful application that can easily recover or restore Windows 2007 files with full of quality.Vitus Localization: An Orchard module containing a collection of features useful for localized or multilingual Orchard websites.Wedn.Net: Blog ????: ????? ??? ?????? ????? ???? ??? ????? ???? ??? ?? ??? ???????

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  • How to disable Alert volume from the command line?

    - by Bryce
    There is an option in the Sound Preferences dialog, Sound Effects tab, to toggle Alert volume 'mute'. It works and suffices for my needs to disable the irritating system beep/bell. However, I reinstall systems a LOT for testing purposes and would like to set this setting in a shell script so it's off without having to fiddle with a GUI. But for the life of me I can't seem to find where this can be toggled via a command line tool. I've scanned through gconf-editor, pulseaudio's pacmd, grepped through /etc, even dug through the gnome-volume-control source code, but I am not seeing how this can be set. I gather that gnome-volume-control has changed since a few releases ago. Ideas?

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  • XNA windows phone release black textures

    - by Lukasz Kajstura
    i just made a 3d game in XNA for windows phone 7. I build it in release mode on visual studio 2010 and suddenly when I run game there is no textures on models - 2 models are black and one is transparent. Models are in .X format exported from 3dsmax and have textures in .jpg also added to game content. I set build action to none and all worked fine in debug mode. When I change to release mode - black textures. When I set build action to compile it gives me warning: Asset was built 2 times with different settings: using TextureImporter and TextureProcessor using TextureImporter and TextureProcessor, referenced by... and still no textures. What can I do?

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  • Silverlight 4 Twitter Client &ndash; Part 7

    - by Max
    Download this article as a PDF Welcome back :) This week we are going to look at something more exciting and a much required feature for any twitter client – auto refresh so as to show new status updates. We are going to achieve this using Silverlight 4 Timers and a bit and refresh our datagrid every 2 minutes to show new updates. We will do this so that we do only minimal request to the twitter api, so that twitter does not block us – there is a limit of 150 request an hour. Let us get started now. Also we will get the profile user id hyperlinked, so that when ever the user click on it, we will take them to their twitter page. Also it was a pain to always run this application by pressing F5, then it would open in a browser you would have to right click uninstall and install it again to see any changes. All this and yet we were not able to debug it :( Now there is a solution for this to run a silverlight application directly out of browser and yet have the debug feature. Super cool, here is how. Right on the Silverlight project and go to debug and then select the Out-Of-Browser application option and choose the *.Web project. Then just right click on the SL project and set as Startup Project. There you go, now every time you press F5, it will automatically run out of browser and still have the debug options. I go to know about this after some binging. Now let us jump to the core straight away. 1) To get the user id hyperlinked, we need to have a DataGridTemplateColumn and within that have a HyperLinkButton. The code for this will  be <data:DataGridTemplateColumn> <data:DataGridTemplateColumn.CellTemplate> <DataTemplate> <HyperlinkButton Click="HyperlinkButton_Click" Content="{Binding UserName}" TargetName="_blank" ></HyperlinkButton> </DataTemplate> </data:DataGridTemplateColumn.CellTemplate> </data:DataGridTemplateColumn> 2) Now let us look at how we are getting this done by looking into HyperlinkButton_Click event handler. There we will dynamically set the NavigateUri to the twitter page. I tried to do this using some binding, eval like stuff as in ASP.NET, but no luck! private void HyperlinkButton_Click(object sender, RoutedEventArgs e) { HyperlinkButton hb = (HyperlinkButton)e.OriginalSource; hb.NavigateUri = new Uri("http://twitter.com/" + hb.Content.ToString(), UriKind.Absolute); } 3) Now we need to switch on our Timer right in the OnNavigated to event on our SL page. So we need to modify our OnNavigated event to some thing like below: protected override void OnNavigatedTo(NavigationEventArgs e) { image1.Source = new BitmapImage(new Uri(GlobalVariable.profileImage, UriKind.Absolute)); this.Title = GlobalVariable.getUserName() + " - Home"; if (!GlobalVariable.isLoggedin()) this.NavigationService.Navigate(new Uri("/Login", UriKind.Relative)); else { currentGrid = "Timeline-Grid"; TwitterCredentialsSubmit(); myDispatcherTimer.Interval = new TimeSpan(0, 0, 0, 60, 0); myDispatcherTimer.Tick += new EventHandler(Each_Tick); myDispatcherTimer.Start(); } } I use a global string – here it is currentGrid variable to indicate what is bound in the datagrid so that after every timer tick, I can rebind the latest data to it again. Like I will only rebind the friends timeline again if the data grid currently holds it and I’ll only rebind the respective list status again in the data grid, if already a list status is bound to the data grid. In the above timer code, its set to trigger the Each_Tick event handler every 1 minute (60 seconds). TimeSpan takes in (days, hours, minutes, seconds, milliseconds). 4) Now we need to set the list name in the currentGrid variable when a list button is clicked. So add the code line below to the list button event handler currentGrid = currentList = b.Content.ToString(); 5) Now let us see how Each_Tick event handler is implemented. public void Each_Tick(object o, EventArgs sender) { if (!currentGrid.Equals("Timeline-Grid")) getListStatuses(currentGrid); else { WebRequest.RegisterPrefix("https://", System.Net.Browser.WebRequestCreator.ClientHttp); WebClient myService = new WebClient(); myService.AllowReadStreamBuffering = true; myService.UseDefaultCredentials = false; myService.Credentials = new NetworkCredential(GlobalVariable.getUserName(), GlobalVariable.getPassword()); myService.DownloadStringCompleted += new DownloadStringCompletedEventHandler(TimelineRequestCompleted); myService.DownloadStringAsync(new Uri("https://twitter.com/statuses/friends_timeline.xml")); } } If the data grid hold friends timeline, I just use the same bit of code we had already to bind the friends timeline to the data grid. Copy Paste. But if it is some list timeline that is bound in the datagrid, I then call the getListStatus method with the currentGrid string which will actually be holding the list name. 6) I wanted to make the hyperlinks inside the status message as hyperlinks and when the user clicks on it, we can then open that link. I tried using a convertor and using a regex to recognize a url and wrap it up with a href, but that is not gonna work in silverlight textblock :( Anyways that convertor code is in the zip file. 7) You can get the complete project files from here. 8) Please comment below for your doubts, suggestions, improvements. I will try to reply as early as possible. Thanks for all your support. Technorati Tags: Silverlight 4,Datagrid,Twitter API,Silverlight Timer

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  • Reproducing a Conversion Deadlock

    - by Alexander Kuznetsov
    Even if two processes compete on only one resource, they still can embrace in a deadlock. The following scripts reproduce such a scenario. In one tab, run this: CREATE TABLE dbo.Test ( i INT ) ; GO INSERT INTO dbo.Test ( i ) VALUES ( 1 ) ; GO SET TRANSACTION ISOLATION LEVEL SERIALIZABLE ; BEGIN TRAN SELECT i FROM dbo.Test ; --UPDATE dbo.Test SET i=2 ; After this script has completed, we have an outstanding transaction holding a shared lock. In another tab, let us have that another connection have...(read more)

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  • CodePlex Daily Summary for Friday, November 30, 2012

    CodePlex Daily Summary for Friday, November 30, 2012Popular ReleasesTFS Branch Permission Removal Event Subscriber: Release 1.0: first release of the Branch Security Inherit Only libraryMagelia WebStore Open-source Ecommerce software: Magelia WebStore 2.2: new UI for the Administration console Bugs fixes and improvement version 2.2.215.3JayData - The cross-platform HTML5 data-management library for JavaScript: JayData 1.2.5: What's new in JayData 1.2.5For detailed release notes check the release notes. Handlebars template engine supportImplement data manager applications with JayData using Handlebars.js for templating. Include JayDataModules/handlebars.js and begin typing the mustaches :) Blogpost: Handlebars templates in JayData Handlebars helpers and model driven commanding in JayData Easy JayStorm cloud data managementManage cloud data using the same syntax and data management concept just like any other data ...nopCommerce. Open source shopping cart (ASP.NET MVC): nopcommerce 2.70: Highlight features & improvements: • Performance optimization. • Search engine optimization. ID-less URLs for products, categories, and manufacturers. • Added ACL support (access control list) on products and categories. • Minify and bundle JavaScript files. • Allow a store owner to decide which billing/shipping address fields are enabled/disabled/required (like it's already done for the registration page). • Moved to MVC 4 (.NET 4.5 is required). • Now Visual Studio 2012 is required to work ...SQL Server Partition Management: Partition Management Release 3.0: Release 3.0 adds support for SQL Server 2012 and is backward compatible with SQL Server 2008 and 2005. The release consists of: • A Readme file • The Executable • The source code (Visual Studio project) Enhancements include: -- Support for Columnstore indexes in SQL Server 2012 -- Ability to create TSQL scripts for staging table and index creation operations -- Full support for global date and time formats, locale independent -- Support for binary partitioning column types -- Fixes to is...NHook - A debugger API: NHook 1.0: x86 debugger Resolve symbol from MS Public server Resolve RVA from executable's image Add breakpoints Assemble / Disassemble target process assembly More information here, you can also check unit tests that are real sample code.PDF Library: PDFLib v2.0: Release notes This new version include many bug fixes and include support for stream objects and cross-reference object streams. New FeatureExtract images from the PDFCommand Line Parser Library: 1.9.3.23 beta: Fixes an issue notified by github user sbambrick about parsing negative numbers.MCEBuddy 2.x: MCEBuddy 2.3.10: Critical Update to 2.3.9: Changelog for 2.3.10 (32bit and 64bit) 1. AsfBin executable missing from build 2. Removed extra references from build to avoid conflict 3. Showanalyzer installation now checked on remote engine machine Changelog for 2.3.9 (32bit and 64bit) 1. Added support for WTV output profile 2. Added support for minimizing MCEBuddy to the system tray 3. Added support for custom archive folder 4. Added support to disable subdirectory monitoring 5. Added support for better TS fil...DotNetNuke® Community Edition CMS: 07.00.00: Major Highlights Fixed issue that caused profiles of deleted users to be available Removed the postback after checkboxes are selected in Page Settings > Taxonomy Implemented the functionality required to edit security role names and social group names Fixed JavaScript error when using a ";" semicolon as a profile property Fixed issue when using DateTime properties in profiles Fixed viewstate error when using Facebook authentication in conjunction with "require valid profile fo...CODE Framework: 4.0.21128.0: See change notes in the documentation section for details on what's new.Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.76: Fixed a typo in ObjectLiteralProperty.IsConstant that caused all object literals to be treated like they were constants, and possibly moved around in the code when they shouldn't be.Kooboo CMS: Kooboo CMS 3.3.0: New features: Dropdown/Radio/Checkbox Lists no longer references the userkey. Instead they refer to the UUID field for input value. You can now delete, export, import content from database in the site settings. Labels can now be imported and exported. You can now set the required password strength and maximum number of incorrect login attempts. Child sites can inherit plugins from its parent sites. The view parameter can be changed through the page_context.current value. Addition of c...Team Foundation Server Administration Tool: 2.2: TFS Administration Tool 2.2 supports the Team Foundation Server 2012 Object Model. Visual Studio 2012 or Team Explorer 2012 must be installed before you can install this tool. You can download and install Team Explorer 2012 from http://aka.ms/TeamExplorer2012. There are no functional changes between the previous release (2.1) and this release.Coding Guidelines for C# 3.0, C# 4.0 and C# 5.0: Coding Guidelines for CSharp 3.0, 4.0 and 5.0: See Change History for a detailed list of modifications.Math.NET Numerics: Math.NET Numerics v2.3.0: Portable Library Build: Adds support for WP8 (.Net 4.0 and higher, SL5, WP8 and .NET for Windows Store apps) New: portable build also for F# extensions (.Net 4.5, SL5 and .NET for Windows Store apps) NuGet: portable builds are now included in the main packages, no more need for special portable packages Linear Algebra: Continued major storage rework, in this release focusing on vectors (previous release was on matrices) Thin QR decomposition (in addition to existing full QR) Static Cr...ExtJS based ASP.NET 2.0 Controls: FineUI v3.2.1: +2012-11-25 v3.2.1 +????????。 -MenuCheckBox?CheckedChanged??????,??????????。 -???????window.IDS??????????????。 -?????(??TabCollection,ControlBaseCollection)???,????????????????。 +Grid??。 -??SelectAllRows??。 -??PageItems??,?????????????,?????、??、?????。 -????grid/gridpageitems.aspx、grid/gridpageitemsrowexpander.aspx、grid/gridpageitems_pagesize.aspx。 -???????????????????。 -??ExpandAllRowExpanders??,?????????????????(grid/gridrowexpanderexpandall2.aspx)。 -??????ExpandRowExpande...VidCoder: 1.4.9 Beta: Updated HandBrake core to SVN 5079. Fixed crashes when encoding DVDs with title gaps.ZXing.Net: ZXing.Net 0.10.0.0: On the way to a release 1.0 the API should be stable now with this version. sync with rev. 2521 of the java version windows phone 8 assemblies improvements and fixesBlackJumboDog: Ver5.7.3: 2012.11.24 Ver5.7.3 (1)SMTP???????、?????????、??????????????????????? (2)?????????、?????????????????????????? (3)DNS???????CNAME????CNAME????????????????? (4)DNS????????????TTL???????? (5)???????????????????????、?????????????????? (6)???????????????????????????????New ProjectsAlpha Solutions Software Engineering Group Project: A Software Engineering Group Project from the University of Northampton.Arduino_Color_Tracker: CMUCAM arduino code for tracking the amount a pixels of the color being tracked.CAudioEndpointVolume: CAudioEndpointVolume for 32 bit and 64 bit Microsoft Office VBACollaborationItem: ?????????????codeplex??,???????????.Commerce Server Contrib Code Generation: A dll and set of T4 templates that help you generate code for interacting with Commerce Server.Commerce Server Contrib Site Templates: A set of site templates and libraries to help you get started with developing sites for Commerce Server.Creation Kit - Script Editor: CKSE is a script editor for Skyrim Papyrus scripts at the moment. Extending to other games is plannned.CSR Fiddle: CSR Fiddle is an App for SharePoint that allows you to "fiddle" with your list and form templates right from the browser.DNN RTL: RTL (Hebrew, Farsi, Arabic etc.) CSS files for Dotnetnuke. CSS files for right to left DNN sites. Dynamic Query: Uses expression tree to dynamically generate Entity Framework query. Also contains tool set for easy integration with asp.net mvc websites.FinalFrontier Autopilot: Autopilot for FinalFrontier MudHorror Encode: ¿pIEnSaS QUe eScRIbiR así eS SoLo PARA ReTrASadOS? Piénsalo dos veces, puede ser que haya un mensaje oculto y tú sólo estés suponiendo demasiado.Interop 2: Microformats for Azure Cloud with OData-InterfaceIT Security Feed Reader: Este es el proyecto de ISec PeruIVO 12_13 A5 Programmeren1 Lessen: Lessen voor de module A5 Programmeren 1 IVO Brugge William SchokkeléLingo: Lingo is a word game developed for Windows Phone 8. It's some sort of word version of Mastermind where you have to guess words in the least amount of guesses.one day one demo: Demos while learning, developing .NET programming skills, e.g. C#, Winform, WPF, WCF, ASP.NET, etc.PDF odd even merger: Merge odd pages with even pages, Useful when you scan a lot of pages from both sides and want to use a feeder ....Print list view button on SharePoint 2010 Ribbon: SP feature with new functionality where you can add "Print Button" on each type of SharePoint lists, even if it is SharePoint Calendar list,Document librariessevengen : 7 segment code calculator and generator: this software helps electrical engineers to calculate codes used in microcontrollers firmwares. SMBC Feebback Module: Bespoke feedback moduleSQL Server Compact Merge Replication Library: This library simplifies the code to do Merge Replication from a SQL Server Compact 3.5 SP2 client, with useful helper methods.Subnetwork Toolkit: The Subnetwork Toolkit is a set of tools to analyze biological subnetworks.uTreeFormat: Umbraco Tree Formatting You can format every documenttype you want by using the alias in the config. Currently only the nodetype 'content' is supported.

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  • "bad mirror archive" : What should I put as the "mirror of ubuntu archive" on installation of ubuntu?

    - by rockit
    I'm trying to set up ubuntu from my old macintosh laptop, but when it asks me to put in the "mirror of ubuntu archive" I run into problems. For the mirror, I put in mirror.anl.gov for the ubuntu archive mirror directory, i put in pub/ubuntu/ Then I leave the http proxy blank and hit "continue" It then tries to "download release files", which starts at 0%, and eventually jumps straight to 100% and then it presents me with an error of "bad mirror archive". Any advice? I never set up ubuntu before, and I'm really struggling with this step.

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  • Reporting Release History : Q1 2010 SP1 (version 4.0.10.421)

    What's NewReport Viewers NEW: Report Viewer for WPF Added zoom modes: Percents/Page Width/Full Page to the Silverlight ViewerTelerik Report WCF Service Added self-hosting capability on WCF service What's FixedReporting API OBSOLETE: Telerik.Reporting.Report.DataMember property; use ObjectDataSource as DataSource and set its DataMember instead. OBSOLETE: Telerik.Reporting.Table.DataMember property; use ObjectDataSource as DataSource and set its DataMember instead. OBSOLETE: Telerik.Reporting.Chart.DataMember...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.

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  • Basis of definitions

    - by Yttrill
    Let us suppose we have a set of functions which characterise something: in the OO world methods characterising a type. In mathematics these are propositions and we have two kinds: axioms and lemmas. Axioms are assumptions, lemmas are easily derived from them. In C++ axioms are pure virtual functions. Here's the problem: there's more than one way to axiomatise a system. Given a set of propositions or methods, a subset of the propositions which is necessary and sufficient to derive all the others is called a basis. So too, for methods or functions, we have a desired set which must be defined, and typically every one has one or more definitions in terms of the others, and we require the programmer to provide instance definitions which are sufficient to allow all the others to be defined, and, if there is an overspecification, then it is consistent. Let me give an example (in Felix, Haskell code would be similar): class Eq[t] { virtual fun ==(x:t,y:t):bool => eq(x,y); virtual fun eq(x:t, y:t)=> x == y; virtual fun != (x:t,y:t):bool => not (x == y); axiom reflex(x:t): x == x; axiom sym(x:t, y:t): (x == y) == (y == x); axiom trans(x:t, y:t, z:t): implies(x == y and y == z, x == z); } Here it is clear: the programmer must define either == or eq or both. If both are defined, the definitions must be equivalent. Failing to define one doesn't cause a compiler error, it causes an infinite loop at run time. Defining both inequivalently doesn't cause an error either, it is just inconsistent. Note the axioms specified constrain the semantics of any definition. Given a definition of == either directly or via a definition of eq, then != is defined automatically, although the programmer might replace the default with something more efficient, clearly such an overspecification has to be consistent. Please note, == could also be defined in terms of !=, but we didn't do that. A characterisation of a partial or total order is more complex. It is much more demanding since there is a combinatorial explosion of possible bases. There is an reason to desire overspecification: performance. There also another reason: choice and convenience. So here, there are several questions: one is how to check semantics are obeyed and I am not looking for an answer here (way too hard!). The other question is: How can we specify, and check, that an instance provides at least a basis? And a much harder question: how can we provide several default definitions which depend on the basis chosen?

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  • JSF 2.2, Interceptors 1.2, and JPA 2.1 Replay: Java EE 7 Launch Webinar Technical Breakouts on YouTube

    - by arungupta
    As stated previously (here, here, and here), the On-Demand Replay of Java EE 7 Launch Webinar is already available. You can watch the entire Strategy and Technical Keynote there, and all other Technical Breakout sessions as well. We are releasing the next set of Technical Breakout sessions on GlassFishVideos YouTube channel as well. In this series, we are releasing JSF 2.2, Interceptors 1.2, and JPA 2.1. Here's the JSF 2.2 session: Here's the Interceptors 1.1 session: Here's the JPA 2.1 session: Enjoy watching them over the next few days before we release the next set of videos! And don't forget to download Java EE 7 SDK and try numerous bundled samples.

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  • Is reliance on parametrized queries the only way to protect against SQL injection?

    - by Chris Walton
    All I have seen on SQL injection attacks seems to suggest that parametrized queries, particularly ones in stored procedures, are the only way to protect against such attacks. While I was working (back in the Dark Ages) stored procedures were viewed as poor practice, mainly because they were seen as less maintainable; less testable; highly coupled; and locked a system into one vendor; (this question covers some other reasons). Although when I was working, projects were virtually unaware of the possibility of such attacks; various rules were adopted to secure the database against corruption of various sorts. These rules can be summarised as: No client/application had direct access to the database tables. All accesses to all tables were through views (and all the updates to the base tables were done through triggers). All data items had a domain specified. No data item was permitted to be nullable - this had implications that had the DBAs grinding their teeth on occasion; but was enforced. Roles and permissions were set up appropriately - for instance, a restricted role to give only views the right to change the data. So is a set of (enforced) rules such as this (though not necessarily this particular set) an appropriate alternative to parametrized queries in preventing SQL injection attacks? If not, why not? Can a database be secured against such attacks by database (only) specific measures? EDIT Emphasis of the question changed slightly, in the light of the initial responses received. Base question unchanged. EDIT2 The approach of relying on paramaterized queries seems to be only a peripheral step in defense against attacks on systems. It seems to me that more fundamental defenses are both desirable, and may render reliance on such queries not necessary, or less critical, even to defend specifically against injection attacks. The approach implicit in my question was based on "armouring" the database and I had no idea whether it was a viable option. Further research has suggested that there are such approaches. I have found the following sources that provide some pointers to this type of approach: http://database-programmer.blogspot.com http://thehelsinkideclaration.blogspot.com The principle features I have taken from these sources is: An extensive data dictionary, combined with an extensive security data dictionary Generation of triggers, queries and constraints from the data dictionary Minimize Code and maximize data While the answers I have had so far are very useful and point out difficulties arising from disregarding paramaterized queries, ultimately they do not answer my original question(s) (now emphasised in bold).

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  • Engine Rendering pipeline : Making shaders generic

    - by fakhir
    I am trying to make a 2D game engine using OpenGL ES 2.0 (iOS for now). I've written Application layer in Objective C and a separate self contained RendererGLES20 in C++. No GL specific call is made outside the renderer. It is working perfectly. But I have some design issues when using shaders. Each shader has its own unique attributes and uniforms that need to be set just before the main draw call (glDrawArrays in this case). For instance, in order to draw some geometry I would do: void RendererGLES20::render(Model * model) { // Set a bunch of uniforms glUniformMatrix4fv(.......); // Enable specific attributes, can be many glEnableVertexAttribArray(......); // Set a bunch of vertex attribute pointers: glVertexAttribPointer(positionSlot, 2, GL_FLOAT, GL_FALSE, stride, m->pCoords); // Now actually Draw the geometry glDrawArrays(GL_TRIANGLES, 0, m->vertexCount); // After drawing, disable any vertex attributes: glDisableVertexAttribArray(.......); } As you can see this code is extremely rigid. If I were to use another shader, say ripple effect, i would be needing to pass extra uniforms, vertex attribs etc. In other words I would have to change the RendererGLES20 render source code just to incorporate the new shader. Is there any way to make the shader object totally generic? Like What if I just want to change the shader object and not worry about game source re-compiling? Any way to make the renderer agnostic of uniforms and attributes etc?. Even though we need to pass data to uniforms, what is the best place to do that? Model class? Is the model class aware of shader specific uniforms and attributes? Following shows Actor class: class Actor : public ISceneNode { ModelController * model; AIController * AI; }; Model controller class: class ModelController { class IShader * shader; int textureId; vec4 tint; float alpha; struct Vertex * vertexArray; }; Shader class just contains the shader object, compiling and linking sub-routines etc. In Game Logic class I am actually rendering the object: void GameLogic::update(float dt) { IRenderer * renderer = g_application->GetRenderer(); Actor * a = GetActor(id); renderer->render(a->model); } Please note that even though Actor extends ISceneNode, I haven't started implementing SceneGraph yet. I will do that as soon as I resolve this issue. Any ideas how to improve this? Related design patterns etc? Thank you for reading the question.

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  • Conflict between Change Control and ASL Mapping

    - by Jie Chen
    Yesterday I got one strange report that on Agile 9.3.1.2, adding a Supplier into Item's Supplier tab will always remove all the data from Item.PageTwo.MultiList01 field which is assigned to a User Group list. The detailed problem description is like below. In JavaClient, MultiList01 attribute on Parts class's PageTwo tab is enabled and assigned with User Group list. On WebClient, user created a new Part and assign MultiList01 with two UserGroups: "Global User Group Test1" and "Personal Group_Test1". Then go to Suppliers tab to add three Suppliers. Switch back to Part's TitleBlock, will see MultiList01 loses the User Group data. To confirm if MultiList01 really loses the data or it saves with other wrong data, I need to check the database and find strange data that MultiList01 saves wrong data ",7976911,7976907,7976959,", which are exactly the ID of these three Suppliers. Then I can suspect the Supplier attribute on Suppliers tab must be mapped to MultiList01. However when I check Supplier in JavaClient, the "ASL mapped to" is blank. More interesting thing is the database clearly shows Supplier attribute (Base ID =2000004219) is mapped to 2090, which is PageTwo.MultiList01 Base ID. Till now, we can get a conclusion that Supplier data is really mapped to MultiList01, though we assign MultiList01 to User Group list and Supplier does not set "ASL mapped to". It must be another function which overrides "ASL mapped to" visibility in JavaClient with high priority. That is the "Change Controlled" function. We immediately see "ASL mapped to" with value "MultiList01" when we disable Change Controlled for Multilist01 If one attribute is Change Controlled, Supplier data cannot be mapped to this attribute theoretically because Supplier could be dynamically modified by users, not by Changes. In real situation of Agile 9.3.1.2, it could be a Code Defect. We can imagine the scenario customer met. He setup Parts.PageTwo.Multilist01 assigned with Supplier list, then in Parts.Suppliers.Supplier attribute, he set "ASL mapped to" to "Multilist01". Later company business is changed, so he set Multilist01 with Change Controlled and re-assign with User Group list. He forgot to remove "ASL mapped to" before he did modifications to Multilist01. Finally we know the solution, it depends on real business. If still need to mapping Supplier to Parts.PageTwo attribute, should modify "ASL mapped to" to other one attribute which already has assigned with Suppliers list. If do not need "ASL mapped to" function, should delete the data from database level. We cannot do it from JavaClient UI. delete propertytable where id in (select p.id from propertytable p, nodetable n where p.parentid =n.id and n.inherit=2000004219 and propertyid=794)

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  • Request Validation in ASP.NET 4.0

    - by Ben Bastiaensen
    Up to ASP.NET 3.5 Request Validation is enabled by default. In order to to disable this for a page you needed to set the ValidationRequest property in the page directive to false. This is no longer the default case in ASP.NET 4.0. If you want to use this behaviour you need to add the follwing setting in web.config  <httpRuntime requestValidationMode="2.0" /> Of course you need to check all input in the page for XSS or other malicious input if you set the pages request validation to false.

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  • Detecting if an object is following a path

    - by justin.m.chase
    I am attempting to take GPS data and track it on a map and see if it follows a given path. I have the path as a set of points and the GPS data streams in as a similar set of points. I am attempting to track the progression of the current position across the path and I am wondering if there are any well known algorithms for this. I have come up with my own that works ok but it is a complex enough problem that I would like to minimize the amount of re-inventing of the wheel that I do. What approach or algorithm would you recommend taking for this problem?

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  • Solving Big Problems with Oracle R Enterprise, Part I

    - by dbayard
    Abstract: This blog post will show how we used Oracle R Enterprise to tackle a customer’s big calculation problem across a big data set. Overview: Databases are great for managing large amounts of data in a central place with rigorous enterprise-level controls.  R is great for doing advanced computations.  Sometimes you need to do advanced computations on large amounts of data, subject to rigorous enterprise-level concerns.  This blog post shows how Oracle R Enterprise enables R plus the Oracle Database enabled us to do some pretty sophisticated calculations across 1 million accounts (each with many detailed records) in minutes. The problem: A financial services customer of mine has a need to calculate the historical internal rate of return (IRR) for its customers’ portfolios.  This information is needed for customer statements and the online web application.  In the past, they had solved this with a home-grown application that pulled trade and account data out of their data warehouse and ran the calculations.  But this home-grown application was not able to do this fast enough, plus it was a challenge for them to write and maintain the code that did the IRR calculation. IRR – a problem that R is good at solving: Internal Rate of Return is an interesting calculation in that in most real-world scenarios it is impractical to calculate exactly.  Rather, IRR is a calculation where approximation techniques need to be used.  In this blog post, we will discuss calculating the “money weighted rate of return” but in the actual customer proof of concept we used R to calculate both money weighted rate of returns and time weighted rate of returns.  You can learn more about the money weighted rate of returns here: http://www.wikinvest.com/wiki/Money-weighted_return First Steps- Calculating IRR in R We will start with calculating the IRR in standalone/desktop R.  In our second post, we will show how to take this desktop R function, deploy it to an Oracle Database, and make it work at real-world scale.  The first step we did was to get some sample data.  For a historical IRR calculation, you have a balances and cash flows.  In our case, the customer provided us with several accounts worth of sample data in Microsoft Excel.      The above figure shows part of the spreadsheet of sample data.  The data provides balances and cash flows for a sample account (BMV=beginning market value. FLOW=cash flow in/out of account. EMV=ending market value). Once we had the sample spreadsheet, the next step we did was to read the Excel data into R.  This is something that R does well.  R offers multiple ways to work with spreadsheet data.  For instance, one could save the spreadsheet as a .csv file.  In our case, the customer provided a spreadsheet file containing multiple sheets where each sheet provided data for a different sample account.  To handle this easily, we took advantage of the RODBC package which allowed us to read the Excel data sheet-by-sheet without having to create individual .csv files.  We wrote ourselves a little helper function called getsheet() around the RODBC package.  Then we loaded all of the sample accounts into a data.frame called SimpleMWRRData. Writing the IRR function At this point, it was time to write the money weighted rate of return (MWRR) function itself.  The definition of MWRR is easily found on the internet or if you are old school you can look in an investment performance text book.  In the customer proof, we based our calculations off the ones defined in the The Handbook of Investment Performance: A User’s Guide by David Spaulding since this is the reference book used by the customer.  (One of the nice things we found during the course of this proof-of-concept is that by using R to write our IRR functions we could easily incorporate the specific variations and business rules of the customer into the calculation.) The key thing with calculating IRR is the need to solve a complex equation with a numerical approximation technique.  For IRR, you need to find the value of the rate of return (r) that sets the Net Present Value of all the flows in and out of the account to zero.  With R, we solve this by defining our NPV function: where bmv is the beginning market value, cf is a vector of cash flows, t is a vector of time (relative to the beginning), emv is the ending market value, and tend is the ending time. Since solving for r is a one-dimensional optimization problem, we decided to take advantage of R’s optimize method (http://stat.ethz.ch/R-manual/R-patched/library/stats/html/optimize.html). The optimize method can be used to find a minimum or maximum; to find the value of r where our npv function is closest to zero, we wrapped our npv function inside the abs function and asked optimize to find the minimum.  Here is an example of using optimize: where low and high are scalars that indicate the range to search for an answer.   To test this out, we need to set values for bmv, cf, t, emv, tend, low, and high.  We will set low and high to some reasonable defaults. For example, this account had a negative 2.2% money weighted rate of return. Enhancing and Packaging the IRR function With numerical approximation methods like optimize, sometimes you will not be able to find an answer with your initial set of inputs.  To account for this, our approach was to first try to find an answer for r within a narrow range, then if we did not find an answer, try calling optimize() again with a broader range.  See the R help page on optimize()  for more details about the search range and its algorithm. At this point, we can now write a simplified version of our MWRR function.  (Our real-world version is  more sophisticated in that it calculates rate of returns for 5 different time periods [since inception, last quarter, year-to-date, last year, year before last year] in a single invocation.  In our actual customer proof, we also defined time-weighted rate of return calculations.  The beauty of R is that it was very easy to add these enhancements and additional calculations to our IRR package.)To simplify code deployment, we then created a new package of our IRR functions and sample data.  For this blog post, we only need to include our SimpleMWRR function and our SimpleMWRRData sample data.  We created the shell of the package by calling: To turn this package skeleton into something usable, at a minimum you need to edit the SimpleMWRR.Rd and SimpleMWRRData.Rd files in the \man subdirectory.  In those files, you need to at least provide a value for the “title” section. Once that is done, you can change directory to the IRR directory and type at the command-line: The myIRR package for this blog post (which has both SimpleMWRR source and SimpleMWRRData sample data) is downloadable from here: myIRR package Testing the myIRR package Here is an example of testing our IRR function once it was converted to an installable package: Calculating IRR for All the Accounts So far, we have shown how to calculate IRR for a single account.  The real-world issue is how do you calculate IRR for all of the accounts?This is the kind of situation where we can leverage the “Split-Apply-Combine” approach (see http://www.cscs.umich.edu/~crshalizi/weblog/815.html).  Given that our sample data can fit in memory, one easy approach is to use R’s “by” function.  (Other approaches to Split-Apply-Combine such as plyr can also be used.  See http://4dpiecharts.com/2011/12/16/a-quick-primer-on-split-apply-combine-problems/). Here is an example showing the use of “by” to calculate the money weighted rate of return for each account in our sample data set.  Recap and Next Steps At this point, you’ve seen the power of R being used to calculate IRR.  There were several good things: R could easily work with the spreadsheets of sample data we were given R’s optimize() function provided a nice way to solve for IRR- it was both fast and allowed us to avoid having to code our own iterative approximation algorithm R was a convenient language to express the customer-specific variations, business-rules, and exceptions that often occur in real-world calculations- these could be easily added to our IRR functions The Split-Apply-Combine technique can be used to perform calculations of IRR for multiple accounts at once. However, there are several challenges yet to be conquered at this point in our story: The actual data that needs to be used lives in a database, not in a spreadsheet The actual data is much, much bigger- too big to fit into the normal R memory space and too big to want to move across the network The overall process needs to run fast- much faster than a single processor The actual data needs to be kept secured- another reason to not want to move it from the database and across the network And the process of calculating the IRR needs to be integrated together with other database ETL activities, so that IRR’s can be calculated as part of the data warehouse refresh processes In our next blog post in this series, we will show you how Oracle R Enterprise solved these challenges.

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  • Music Rhythm Game Difficulty Question

    - by David Dimalanta
    I have curious question about music rhythm based genre while I'm making a code for the game. Is it really better if I set a random pattern encountered on every music played or there is a specific pattern depending on the music and the difficulty? I have observed the Guitar Hero 3 game for the game console where the difficulty is set on the number of strings used and possible number of combo (e.g. two-string combo). Compared to the Tap Tap Revenge for the Android and iPhone, the difficulty based on the number of BPM (Beat per Minute), meaning, number of targets spawn and must be hit.

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  • I can't start airodump-ng (aircrack-ng)

    - by Guido Ferzoco Plumari
    This is what I receive when starting airodump-ng root@guido-laptop:/home/guido# airodump-ng wlan0 ioctl(SIOCSIWMODE) failed: Device or resource busy ARP linktype is set to 1 (Ethernet) - expected ARPHRD_IEEE80211, ARPHRD_IEEE80211_FULL or ARPHRD_IEEE80211_PRISM instead. Make sure RFMON is enabled: run 'airmon-ng start wlan0 <#>' Sysfs injection support was not found either. Original question in spanish: No puedo iniciar airodump-ng (aircrack-ng) Esto lo que me sale al iniciar airodump-ng root@guido-laptop:/home/guido# airodump-ng wlan0 ioctl(SIOCSIWMODE) failed: Device or resource busy ARP linktype is set to 1 (Ethernet) - expected ARPHRD_IEEE80211, ARPHRD_IEEE80211_FULL or ARPHRD_IEEE80211_PRISM instead. Make sure RFMON is enabled: run 'airmon-ng start wlan0 <#>' Sysfs injection support was not found either.

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