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  • How do I classify using GLCM and SVM Classifier in Matlab?

    - by Gomathi
    I'm on a project of liver tumor segmentation and classification. I used Region Growing and FCM for liver and tumor segmentation respectively. Then, I used Gray Level Co-occurence matrix for texture feature extraction. I have to use Support Vector Machine for Classification. But I don't know how to normalize the feature vectors. Can anyone tell how to program it in Matlab? To the GLCM program, I gave the tumor segmented image as input. Was I correct? If so, I think, then, my output will also be correct. My glcm coding, as far as I have tried is, I = imread('fzliver3.jpg'); GLCM = graycomatrix(I,'Offset',[2 0;0 2]); stats = graycoprops(GLCM,'all') t1= struct2array(stats) I2 = imread('fzliver4.jpg'); GLCM2 = graycomatrix(I2,'Offset',[2 0;0 2]); stats2 = graycoprops(GLCM2,'all') t2= struct2array(stats2) I3 = imread('fzliver5.jpg'); GLCM3 = graycomatrix(I3,'Offset',[2 0;0 2]); stats3 = graycoprops(GLCM3,'all') t3= struct2array(stats3) t=[t1;t2;t3] xmin = min(t); xmax = max(t); scale = xmax-xmin; tf=(x-xmin)/scale Was this a correct implementation? Also, I get an error at the last line. My output is: stats = Contrast: [0.0510 0.0503] Correlation: [0.9513 0.9519] Energy: [0.8988 0.8988] Homogeneity: [0.9930 0.9935] t1 = Columns 1 through 6 0.0510 0.0503 0.9513 0.9519 0.8988 0.8988 Columns 7 through 8 0.9930 0.9935 stats2 = Contrast: [0.0345 0.0339] Correlation: [0.8223 0.8255] Energy: [0.9616 0.9617] Homogeneity: [0.9957 0.9957] t2 = Columns 1 through 6 0.0345 0.0339 0.8223 0.8255 0.9616 0.9617 Columns 7 through 8 0.9957 0.9957 stats3 = Contrast: [0.0230 0.0246] Correlation: [0.7450 0.7270] Energy: [0.9815 0.9813] Homogeneity: [0.9971 0.9970] t3 = Columns 1 through 6 0.0230 0.0246 0.7450 0.7270 0.9815 0.9813 Columns 7 through 8 0.9971 0.9970 t = Columns 1 through 6 0.0510 0.0503 0.9513 0.9519 0.8988 0.8988 0.0345 0.0339 0.8223 0.8255 0.9616 0.9617 0.0230 0.0246 0.7450 0.7270 0.9815 0.9813 Columns 7 through 8 0.9930 0.9935 0.9957 0.9957 0.9971 0.9970 ??? Error using ==> minus Matrix dimensions must agree. The images are:

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  • Stencil mask with AlphaTestEffect

    - by Brendan Wanlass
    I am trying to pull off the following effect in XNA 4.0: http://eng.utah.edu/~brendanw/question.jpg The purple area has 50% opacity. I have gotten pretty close with the following code: public static DepthStencilState AlwaysStencilState = new DepthStencilState() { StencilEnable = true, StencilFunction = CompareFunction.Always, StencilPass = StencilOperation.Replace, ReferenceStencil = 1, DepthBufferEnable = false, }; public static DepthStencilState EqualStencilState = new DepthStencilState() { StencilEnable = true, StencilFunction = CompareFunction.Equal, StencilPass = StencilOperation.Keep, ReferenceStencil = 1, DepthBufferEnable = false, }; ... if (_alphaEffect == null) { _alphaEffect = new AlphaTestEffect(_spriteBatch.GraphicsDevice); _alphaEffect.AlphaFunction = CompareFunction.LessEqual; _alphaEffect.ReferenceAlpha = 129; Matrix projection = Matrix.CreateOrthographicOffCenter(0, _spriteBatch.GraphicsDevice.PresentationParameters.BackBufferWidth, _spriteBatch.GraphicsDevice.PresentationParameters.BackBufferHeight, 0, 0, 1); _alphaEffect.Projection = world.SystemManager.GetSystem<RenderSystem>().Camera.View * projection; } _mask = new RenderTarget2D(_spriteBatch.GraphicsDevice, _spriteBatch.GraphicsDevice.PresentationParameters.BackBufferWidth, _spriteBatch.GraphicsDevice.PresentationParameters.BackBufferHeight, false, SurfaceFormat.Color, DepthFormat.Depth24Stencil8); _spriteBatch.GraphicsDevice.SetRenderTarget(_mask); _spriteBatch.GraphicsDevice.Clear(ClearOptions.Target | ClearOptions.Stencil, Color.Transparent, 0, 0); _spriteBatch.Begin(SpriteSortMode.Immediate, null, null, AlwaysStencilState, null, _alphaEffect); _spriteBatch.Draw(sprite.Texture, position, sprite.SourceRectangle,Color.White, 0f, sprite.Origin, 1f, SpriteEffects.None, 0); _spriteBatch.End(); _spriteBatch.Begin(SpriteSortMode.Immediate, null, null, EqualStencilState, null, null); _spriteBatch.Draw(_maskTex, new Vector2(x * _maskTex.Width, y * _maskTex.Height), null, Color.White, 0f, Vector2.Zero, 1f, SpriteEffects.None, 0); _spriteBatch.End(); _spriteBatch.GraphicsDevice.SetRenderTarget(null); _spriteBatch.GraphicsDevice.Clear(Color.Black); _spriteBatch.Begin(); _spriteBatch.Draw((Texture2D)_mask, Vector2.Zero, null, Color.White, 0f, Vector2.Zero, 1f, SpriteEffects.None, layer/max_layer); _spriteBatch.End(); My problem is, I can't get the AlphaTestEffect to behave. I can either mask over the semi-transparent purple junk and fill it in with the green design, or I can draw over the completely opaque grassy texture. How can I specify the exact opacity that needs to be replace with the green design?

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  • Steam freezes at login screen

    - by Snail284069
    I have just installed Steam on Xubuntu, and after it finished installing it went to the login screen, but the screen is frozen, and I cannot press the buttons. When running Steam though the terminal it says: alex@Craptop:~$ steam Running Steam on ubuntu 14.04 32-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) Gtk-Message: Failed to load module "overlay-scrollbar" Gtk-Message: Failed to load module "unity-gtk-module" Installing breakpad exception handler for appid(steam)/version(1400690891_client) [0522/174755:WARNING:proxy_service.cc(958)] PAC support disabled because there is no system implementation Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) [HTTP Remote Control] HTTP server listening on port 35849. Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) Process 2764 created /alex-ValveIPCSharedObjects5 Installing breakpad exception handler for appid(steam)/version(1400690891_client) Generating new string page texture 12: 48x256, total string texture memory is 49.15 KB Generating new string page texture 13: 256x256, total string texture memory is 311.30 KB Generating new string page texture 14: 128x256, total string texture memory is 442.37 KB Generating new string page texture 15: 384x256, total string texture memory is 835.58 KB and then the terminal gets stuck too, letting me type into it but not doing anything. I tried reinstalling and restarting the computer, but it still keeps happening.

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  • Best practice for setting Effect parameters in XNA

    - by hichaeretaqua
    I want to ask if there is a best practice for setting Effect parameters in XNA. Or in other words, what exactly happens when I call pass.Apply(). I can imagine multiple scenarios: Each time Apply is called, all effect parameters are transferred to the GPU and therefor it has no real influence how often I set a parameter. Each time Apply is called, only the parameters that got reset are transferred. So caching Set-operations that don't actually set a new value should be avoided. Each time Apply is called, only the parameters that got changed are transferred. So caching Set-operations is useless. This whole questions is bootless because no one of the mentions ways has any noteworthy impact on game performance. So the final question: Is it useful to implement some caching of set operation like: private Matrix _world; public Matrix World { get{ return _world; } set { if (value == world) return; _effect.Parameters["xWorld"].SetValue(value); _world = value; } } Thanking you in anticipation.

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  • Extreme Optimization Numerical Libraries for .NET – Part 1 of n

    - by JoshReuben
    While many of my colleagues are fascinated in constructing the ultimate ViewModel or ServiceBus, I feel that this kind of plumbing code is re-invented far too many times – at some point in the near future, it will be out of the box standard infra. How many times have you been to a customer site and built a different variation of the same kind of code frameworks? How many times can you abstract Prism or reliable and discoverable WCF communication? As the bar is raised for whats bundled with the framework and more tasks become declarative, automated and configurable, Information Systems will expose a higher level of abstraction, forcing software engineers to focus on more advanced computer science and algorithmic tasks. I've spent the better half of the past decade building skills in .NET and expanding my mathematical horizons by working through the Schaums guides. In this series I am going to examine how these skillsets come together in the implementation provided by ExtremeOptimization. Download the trial version here: http://www.extremeoptimization.com/downloads.aspx Overview The library implements a set of algorithms for: linear algebra, complex numbers, numerical integration and differentiation, solving equations, optimization, random numbers, regression, ANOVA, statistical distributions, hypothesis tests. EONumLib combines three libraries in one - organized in a consistent namespace hierarchy. Mathematics Library - Extreme.Mathematics namespace Vector and Matrix Library - Extreme.Mathematics.LinearAlgebra namespace Statistics Library - Extreme.Statistics namespace System Requirements -.NET framework 4.0  Mathematics Library The classes are organized into the following namespace hierarchy: Extreme.Mathematics – common data types, exception types, and delegates. Extreme.Mathematics.Calculus - numerical integration and differentiation of functions. Extreme.Mathematics.Curves - points, lines and curves, including polynomials and Chebyshev approximations. curve fitting and interpolation. Extreme.Mathematics.Generic - generic arithmetic & linear algebra. Extreme.Mathematics.EquationSolvers - root finding algorithms. Extreme.Mathematics.LinearAlgebra - vectors , matrices , matrix decompositions, solvers for simultaneous linear equations and least squares. Extreme.Mathematics.Optimization – multi-d function optimization + linear programming. Extreme.Mathematics.SignalProcessing - one and two-dimensional discrete Fourier transforms. Extreme.Mathematics.SpecialFunctions

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  • Where should I place my reaction code in Per-Pixel Collision Detection?

    - by CJ Cohorst
    I have this collision detection code: public bool PerPixelCollision(Player player, Game1 dog) { Matrix atob = player.Transform * Matrix.Invert(dog.Transform); Vector2 stepX = Vector2.TransformNormal(Vector2.UnitX, atob); Vector2 stepY = Vector2.TransformNormal(Vector2.UnitY, atob); Vector2 iBPos = Vector2.Transform(Vector2.Zero, atob); for(int deltax = 0; deltax < player.playerTexture.Width; deltax++) { Vector2 bpos = iBPos; for (int deltay = 0; deltay < player.playerTexture.Height; deltay++) { int bx = (int)bpos.X; int by = (int)bpos.Y; if (bx >= 0 && bx < dog.dogTexture.Width && by >= 0 && by < dog.dogTexture.Height) { if (player.TextureData[deltax + deltay * player.playerTexture.Width].A > 150 && dog.TextureData[bx + by * dog.Texture.Width].A > 150) { return true; } } bpos += stepY; } iBPos += stepX; } return false; } What I want to know is where to put in the code where something happens. For example, I want to put in player.playerPosition.X -= 200 just as a test, but I don't know where to put it. I tried putting it under the return true and above it, but under it, it said unreachable code, and above it nothing happened. I also tried putting it by bpos += stepY; but that didn't work either. Where do I put the code?

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  • New install of Steam not running on new install of Ubuntu 13.10

    - by inferKNOX
    I tried purging steam, un-installing and reinstalling steam, deleting /home/.steam/share/steam/appcache/, deleting everything in /home/.steam/share/steam/ and nothing helped. I installed Ubuntu, then steam into it directly afterward. I installed steam from Ubuntu Software Centre, launched it, it updated 206MB, then closed. When I tried to launch it again, it momentarily flashes the checking for update dialogue, then closes every time. Then (in an unrelated event) Ubuntu said some system updates are necessary and one of them was Steam launcher. I did the update, tried to launch Steam; same story. Really need help on this, as I did a complete re-isntall of Ubuntu, then Steam again and it did not help at all. Here's the log: user@computer:~$ steam Running Steam on ubuntu 13.10 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(1381282832_client) Installing breakpad exception handler for appid(steam)/version(1381282832_client) Installing breakpad exception handler for appid(steam)/version(1381282832_client) unlinked 0 orphaned pipes removing stale semaphore last operated on by process 2297 with name 0eBlobRegistryMutex_313E4D748EE12691A95DDE8913185F7E removing stale semaphore last operated on by process 2297 with name 0eBlobRegistrySignal_313E4D748EE12691A95DDE8913185F7E removing stale semaphore last operated on by process 2297 with name 0emSteamEngineInstance removing stale semaphore last operated on by process 2297 with name 0eSteamEngineLock Gtk-Message: Failed to load module "overlay-scrollbar" Gtk-Message: Failed to load module "unity-gtk-module" Installing breakpad exception handler for appid(steam)/version(1381282832_client) Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number [1030/115016:WARNING:proxy_service.cc(958)] PAC support disabled because there is no system implementation Installing breakpad exception handler for appid(steam)/version(1381282832_client) Installing breakpad exception handler for appid(steam)/version(1381282832_client) Installing breakpad exception handler for appid(steam)/version(1381282832_client) Installing breakpad exception handler for appid(steam)/version(1381282832_client) Steam: An X Error occurred X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 18 (X_ChangeProperty) Value in failed request: 0x0 Serial number of failed request: 105 xerror_handler: X failed, continuing Uploading dump (out-of-process) [proxy ''] /tmp/dumps/crash_20131030115012_1.dmp /home/user/.local/share/Steam/steam.sh: line 717: 2650 Segmentation fault (core dumped) $STEAM_DEBUGGER "$STEAMROOT/$PLATFORM/$STEAMEXE" "$@" Finished uploading minidump (out-of-process): success = yes response: CrashID=bp-484ddae7-0b1c-4ae4-be84-42a9c2131030 Thanks in advance.

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  • Rotation of bitmap using a frame by frame animation

    - by pengume
    Hey every one I know this has probably been asked a ton of times but I just wanted to clarify if I am approaching this correctly, since I ran into some problems rotating a bitmap. So basically I have one large bitmap that has four frames drawn on it and I only draw one at a time by looping through the bitmap by increments to animate walking. I can get the bitmap to rotate correctly when it is not moving but once the animation starts it starts to cut off alot of the image and sometimes becomes very fuzzy. I have tried public void draw(Canvas canvas,int pointerX, int pointerY) { Matrix m; if (setRotation){ // canvas.save(); m = new Matrix(); m.reset(); // spriteWidth and spriteHeight are for just the current frame showed m.setTranslate(spriteWidth / 2, spriteHeight / 2); //get and set rotation for ninja based off of joystick m.preRotate((float) GameControls.getRotation()); //create the rotated bitmap flipedSprite = Bitmap.createBitmap(bitmap , 0, 0,bitmap.getWidth(),bitmap.getHeight() , m, true); //set new bitmap to rotated ninja setBitmap(flipedSprite); // canvas.restore(); Log.d("Ninja View", "angle of rotation= " +(float) GameControls.getRotation()); setRotation = false; } And then the Draw Method here // create the destination rectangle for the ninjas current animation frame // pointerX and pointerY are from the joystick moving the ninja around destRect = new Rect(pointerX, pointerY, pointerX + spriteWidth, pointerY + spriteHeight); canvas.drawBitmap(bitmap, getSourceRect(), destRect, null); The animation is four frames long and gets incremented by 66 (the size of one of the frames on the bitmap) for every frame and then back to 0 at the end of the loop.

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  • Best practice settings Effect parameters in XNA

    - by hichaeretaqua
    I want to ask if there is a best practice settings effect parameters in XNA. Or in other words, what exactly happens when I call pass.Apply(). I can imagine multiple scenarios: Each time Apply() is called, all effect parameters are transferred to the GPU and therefor it has no real influence how often I set a parameter. Each time Apply() is called, only the parameters that got reset are transferred. So caching Set-operations that don't actually set a new value should be avoided. Each time Apply() is called, only the parameters that got changed are transferred. So caching Set-operations is useless. This whole questions is bootless because no one of the mentions ways has any noteworthy impact on game performance. So the final question: Is it useful to implement some caching of Set-operation like: private Matrix _world; public Matrix World { get{ return _world;} set { if(value == world)return; _effect.Parameters["xWorld"].SetValue(value); _world = value; } Thanking you in anticipation

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  • Missing z-axis rotation for transforming between two vectors

    - by Steve Baughman
    I'm trying to rotate a cube so that it's facing up, but am getting hung up on the final implementation details. It now reliably will rotate the x,y axis to the correct side, but the z-axis is never rotating (See photos of before and after rotation). When I'm using the code below I always get '0' for my rotationVector.z. What am I missing here? // Define lookAt vector lookAtVector = GLKVector3Make(0,0,1); // Define axes vectors axes[0] = GLKVector3Make(0,0,1); axes[1] = GLKVector3Make(-1,0,0); axes[2] = GLKVector3Make(0,1,0); axes[3] = GLKVector3Make(1,0,0); axes[4] = GLKVector3Make(0,-1,0); axes[5] = GLKVector3Make(0,0,-1); CGFloat highest_dot = -1.0; GLKVector3 closest_axis; for(int i = 0; i < 6; i++) { // multiply cube's axes by existing matrix GLKVector3 axis = GLKMatrix4MultiplyVector3(matrix, axes[i]); CGFloat dot = GLKVector3DotProduct(axis, lookAtVector); if(dot > highest_dot) { closest_axis = axis; highest_dot = dot; } } GLKVector3 rotationVector = GLKVector3CrossProduct(closest_axis, lookAtVector); // Get angle between vectors CGFloat angle = atan2(GLKVector3Length(rotationVector), GLKVector3DotProduct(closest_axis, lookAtVector)); // normalize the rotation vector rotationVector = GLKVector3Normalize(rotationVector); // Create transform CATransform3D rotationTransform = CATransform3DMakeRotation(angle, rotationVector.x, rotationVector.y, rotationVector.z); // add rotation transform to existing transformation baseTransform = CATransform3DConcat(baseTransform, rotationTransform); return baseTransform; Before 3d Rotation After 3d Rotation Implementation based on this post

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  • Frustum culling with third person camera

    - by Christian Frantz
    I have a third person camera that contains two matrices: view and projection, and two Vector3's: camPosition and camTarget. I've read up on frustum culling and it makes it seem easy enough for a first person camera, but how would I implement this for a third person camera? I need to take into effect the objects I can see behind me too. How would I implement this into my camera class so it runs at the same time as my update method? public void CameraUpdate(Matrix objectToFollow) { camPosition = objectToFollow.Translation + (objectToFollow.Backward *backward) + (objectToFollow.Up * up); camTarget = objectToFollow.Translation; view = Matrix.CreateLookAt(camPosition, camTarget, Vector3.Up); } Can I just create another method within the class which creates a bounding sphere with a value from my camera and then uses the culling based on that? And if so, which value am I using to create the bounding sphere from? After this is implemented, I'm planning on using occlusion culling for the faces of my objects adjacent to other objects. Will using just one or the other make a difference? Or will both of them be better? I'm trying to keep my framerate as high as possible

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  • Camera Collision inside the room model

    - by sanddy
    I am having a problem in Calculating the camera collision for my Room model which consists of sofa, tables and other models. The users shall be moving the camera front, back, rotating so i need to make sure that the camera does not collide with any of the models with in the room. I have treated all my models inside the room by BoundingBox[] and the camera by BoundingSphere. So, far i have implemented collision by looking into the tutorial from http://www.toymaker.info/Games/XNA/html/xna_model_collisions.html which was great. But, I guess the problem lies in the Transformation part. I debugged and found some points to be at Vector(-XXX,-XXX,-XXX) where X is digit. Also i found my radius of some models where too large(in thousand, i just looked into its radius value before converting to BoundingBox). Do I need to scale the model for collision??? Below are my code:- On My LoadContent(): Matrix[] transforms = new Matrix[myModel.Bones.Count]; myModel.CopyAbsoluteBoneTransformsTo(transforms); int index = 0; box = new List<BoundingBox>(); BoundingBox worldModel = Utility.CalculateBoundingBox(myModel); foreach (ModelMesh mesh in myModel.Meshes) { Vector3[] obb = new Vector3[8]; worldModel.GetCorners(obb); Vector3[] asdf = (Vector3[])obb.Clone(); Vector3.Transform(obb, ref transforms[mesh.ParentBone.Index], obb); BoundingBox worldBox = BoundingBox.CreateFromPoints(obb); box.Add(worldBox); index++; } On CameraPosition Update: BoundingSphere bs = new BoundingSphere(this.cameraPos, 5.0f); if (RoomWalkthrough.Utility.CheckCollision(bs, bb)) { // Do Something } Please Help.

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  • Using orientation to calculate position on Windows Phone 7

    - by Lavinski
    I'm using the motion API and I'm trying to figure out a control scheme for the game I'm currently developing. What I'm trying to achive is for a orienation of the device to correlate directly to a position. Such that tilting the phone forward and to the left represents the top left position and back to the right would be the bottom right position. Photos to make it clearer (the red dot would be the calculated position). Forward and Left Back and Right Now for the tricky bit. I also have to make sure that the values take into account left landscape and right landscape device orientations (portrait is the default so no calculations would be needed for it). Has anyone done anything like this? Notes: I've tried using the yaw, pitch, roll and Quaternion readings. Sample: // Get device facing vector public static Vector3 GetState() { lock (lockable) { var down = Vector3.Forward; var direction = Vector3.Transform(down, state); switch (Orientation) { case Orientation.LandscapeLeft: return Vector3.TransformNormal(direction, Matrix.CreateRotationZ(-rightAngle)); case Orientation.LandscapeRight: return Vector3.TransformNormal(direction, Matrix.CreateRotationZ(rightAngle)); } return direction; } }

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  • Oracle Internet Directory 11gR1 11.1.1.6 Certified with Oracle E-Business Suite

    - by B Shashikumar
    We are very pleased to announce that Oracle Internet Directory 11gR1 (11.1.1.6) is now certified with Oracle E-Business Suite Releases 11i, 12.0 and 12.1. With this certification, we are offering several benefits to Oracle E-Business Suite customers: · Massive Scale: Oracle Internet Directory (OID) is a proven solution for mission critical deployments. OID can scale to extremely large deployments on less hardware as demonstrated by its published Two-Billion-User Benchmark. This reduces the footprint required to deploy enterprise directory services in the data-center resulting in cost savings and a greener enterprise. · Enhanced Security: OID is the most secure directory service that provides security at every level from data in transit to storage and backups. In addition to LDAP security, it leverages powerful Oracle database security features like Database Vault and Transparent Data Encryption · Investment Protection: This certification leverages Identity Management’s hot-pluggable capabilities enabling E-Business Suite customers to store and manage user identities in existing directory servers thus helping them maximize their investments For a complete matrix of platforms supported by Oracle Internet Directory and its components, refer to the Oracle Identity and Access Management 11gR1 certification matrix. For more information about this certification, check out the Oracle E-Business Suite blog. 

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  • Adding complexity by generalising: how far should you go?

    - by marcog
    Reference question: http://stackoverflow.com/questions/4303813/help-with-interview-question The above question asked to solve a problem for an NxN matrix. While there was an easy solution, I gave a more general solution to solve the more general problem for an NxM matrix. A handful of people commented that this generalisation was bad because it made the solution more complex. One such comment is voted +8. Putting aside the hard-to-explain voting effects on SO, there are two types of complexity to be considered here: Runtime complexity, i.e. how fast does the code run Code complexity, i.e. how difficult is the code to read and understand The question of runtime complexity is something that requires a better understanding of the input data today and what it might look like in the future, taking the various growth factors into account where necessary. The question of code complexity is the one I'm interested in here. By generalising the solution, we avoid having to rewrite it in the event that the constraints change. However, at the same time it can often result in complicating the code. In the reference question, the code for NxN is easy to understand for any competent programmer, but the NxM case (unless documented well) could easily confuse someone coming across the code for the first time. So, my question is this: Where should you draw the line between generalising and keeping the code easy to understand?

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  • Creating Parent-Child Relationships in SSRS

    - by Tim Murphy
    As I have been working on SQL Server Reporting Services reports the last couple of weeks I ran into a scenario where I needed to present a parent-child data layout.  It is rare that I have seen a report that was a simple tabular or matrix format and this report continued that trend.  I found that the processes for developing complex SSRS reports aren’t as commonly described as I would have thought.  Below I will layout the process that I went through to create a solution. I started with a List control which will contain the layout of the master (parent) information.  This allows for a main repeating report part.  The dataset for this report should include the data elements needed to be passed to the subreport as parameters.  As you can see the layout is simply text boxes that are bound to the dataset. The next step is to set a row group on the List row.  When the dialog appears select the field that you wish to group your report by.  A good example in this case would be the employee name or ID. Create a second report which becomes the subreport.  The example below has a matrix control.  Create the report as you would any parameter driven document by parameterizing the dataset. Add the subreport to the main report inside the row of the List control.  This can be accomplished by either dragging the report from the solution explorer or inserting a Subreport control and then setting the report name property. The last step is to set the parameters on the subreport.  In this case the subreport has EmpId and ReportYear as parameters.  While some of the documentation on this states that the dialog will automatically detect the child parameters, but this has not been my experience.  You must make sure that the names match exactly.  Tie the name of the parameter to either a field in the dataset or a parameter of the parent report. del.icio.us Tags: SQL Server Reporting Services,SSRS,SQL Server,Subreports

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  • GLSL billboard move center of rotation

    - by Jacob Kofoed
    I have successfully set up a billboard shader that works, it can take in a quad and rotate it so it always points toward the screen. I am using this vertex-shader: void main(){ vec4 tmpPos = (MVP * bufferMatrix * vec4(0.0, 0.0, 0.0, 1.0)) + (MV * vec4( vertexPosition.x * 1.0 * bufferMatrix[0][0], vertexPosition.y * 1.0 * bufferMatrix[1][1], vertexPosition.z * 1.0 * bufferMatrix[2][2], 0.0) ); UV = UVOffset + vertexUV * UVScale; gl_Position = tmpPos; BufferMatrix is the model-matrix, it is an attribute to support Instance-drawing. The problem is best explained through pictures: This is the start position of the camera: And this is the position, looking in from 45 degree to the right: Obviously, as each character is it's own quad, the shader rotates each one around their own center towards the camera. What I in fact want is for them to rotate around a shared center, how would I do this? What I have been trying to do this far is: mat4 translation = mat4(1.0); translation = glm::translate(translation, vec3(pos)*1.f * 2.f); translation = glm::scale(translation, vec3(scale, 1.f)); translation = glm::translate(translation, vec3(anchorPoint - pos) / vec3(scale, 1.f)); Where the translation is the bufferMatrix sent to the shader. What I am trying to do is offset the center, but this might not be possible with a single matrix..? I am interested in a solution that doesn't require CPU calculations each frame, but rather set it up once and then let the shader do the billboard rotation. I realize there's many different solutions, like merging all the quads together, but I would first like to know if the approach with offsetting the center is possible. If it all seems a bit confusing, it's because I'm a little confused myself.

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  • 3D zooming technique to maintain the relative position of an object on screen

    - by stark
    Is it possible to zoom to a certain point on screen by modifying the field of view and rotating the view of the camera as to keep that point/object in the same place on screen while zooming ? Changing the camera position is not allowed. I projected the 3D pos of the object on screen and remembered it. Then on each frame I calculate the direction to it in camera space and then I construct a rotation matrix to align this direction to Z axis (in cam space). After this, I calculate the direction from the camera to the object in world space and transform this vector with the matrix I obtained earlier and then use this final vector as the camera's new direction. And it's actually "kinda working", the problem is that it is more/less off than the camera's rotation before starting to zoom depending on the area you are trying to zoom in (larger error on edges/corners). It looks acceptable, but I'm not settling for only this. Any suggestions/resources for doing this technique perfectly? If some of you want to explain the math in detail, be my guest, I can understand these things well.

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  • Adding complexity by generalising: how far should you go?

    - by marcog
    Reference question: http://stackoverflow.com/questions/4303813/help-with-interview-question The above question asked to solve a problem for an NxN matrix. While there was an easy solution, I gave a more general solution to solve the more general problem for an NxM matrix. A handful of people commented that this generalisation was bad because it made the solution more complex. One such comment is voted +8. Putting aside the hard-to-explain voting effects on SO, there are two types of complexity to be considered here: Runtime complexity, i.e. how fast does the code run Code complexity, i.e. how difficult is the code to read and understand The question of runtime complexity is something that requires a better understanding of the input data today and what it might look like in the future, taking the various growth factors into account where necessary. The question of code complexity is the one I'm interested in here. By generalising the solution, we avoid having to rewrite it in the event that the constraints change. However, at the same time it can often result in complicating the code. In the reference question, the code for NxN is easy to understand for any competent programmer, but the NxM case (unless documented well) could easily confuse someone coming across the code for the first time. So, my question is this: Where should you draw the line between generalising and keeping the code easy to understand?

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  • Adjust sprite bounds of the visible part of texture

    - by Crazy D0G
    Is there any way to adjust the boundaries of the visible part of the sprite? To make it easier to understand: I have a texture, such as shown at figure 1. Then I break it into pieces and fill the resulting fragments using PRKit (wood texture on figure 2 and 3). But the resulting fragments have the transparent (green color on figure 2 and 3) and when creating a sprite from the fragments they have the size of the initial texture. Is there a way to get rid of this transparency and to adjust the size of the visible part (wood texture), openGL or cocos2d-x means? Maybe it help - draw() method from PRKit: void PRFilledPolygon::draw() { //CCNode::draw(); glDisableClientState(GL_COLOR_ARRAY); // we have a pointer to vertex points so enable client state glBindTexture(GL_TEXTURE_2D, texture->getName()); glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_ONE_MINUS_SRC_ALPHA); glVertexPointer(2, GL_FLOAT, 0, areaTrianglePoints); glTexCoordPointer(2, GL_FLOAT, 0, textureCoordinates); glDrawArrays(GL_TRIANGLES, 0, areaTrianglePointCount); glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); //Restore texture matrix and switch back to modelview matrix glEnableClientState(GL_COLOR_ARRAY);}

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  • Should you create a class within a method?

    - by Amndeep7
    I have made a program using Java that is an implementation of this project: http://nifty.stanford.edu/2009/stone-random-art/sml/index.html. Essentially, you create a mathematical expression and, using the pixel coordinate as input, make a picture. After I initially implemented this in serial, I then implemented it in parallel due to the fact that if the picture size is too large or if the mathematical expression is too complex (especially considering the fact that I made the expression recursively), it takes a really long time. During this process, I realized that I needed two classes which implemented the Runnable interface as I had to put in parameters for the run method, which you aren't allowed to do directly. One of these classes ended up being a medium sized static inner class (not large enough to make an independent class file for it though). The other though, just needed a few parameters to determine some indexes and the size of the for loop that I was making run in parallel - here it is: class DataConversionRunnable implements Runnable { int jj, kk, w; DataConversionRunnable(int column, int matrix, int wid) { jj = column; kk = matrix; w = wid; } public void run() { for(int i = 0; i < w; i++) colorvals[kk][jj][i] = (int) ((raw[kk][jj][i] + 1.0) * 255 / 2.0); increaseCounter(); } } My question is should I make it a static inner class or can I just create it in a method? What is the general programming convention followed in this case?

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  • If a library doesn't provide all my needs, how should I proceed?

    - by 9a3eedi
    I'm developing an application involving math and physics models, and I'd like to use a Math library for things like Matrices. I'm using C#, and so I was looking for some libraries and found Math.NET. I'm under the impression, from past experience, that for math, using a robust and industry-approved third party library is much better than writing your own code. It seems good for many purposes, but it does not provide support for Quaternions, which I need to use as a type. Also, I need some functions in Vector and Matrix that also aren't provided, such as rotation matrices and vector rotation functions, and calculating cross products. At the same time, it provides a lot of functions/classes that I simply do not need, which might mean a lot of unnecessary bloat and complexity. At this rate, should I even bother using the library? Should I write my own math library? Or is it a better idea to stick to the third party library and somehow wrap around it? Perhaps I should make a subclass of the Matrix and Vector type of the library? But isn't that considered bad style? I've also tried looking for other libraries but unfortunately I couldn't find anything suitable.

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  • Basic 3D Collision detection in XNA 4.0

    - by NDraskovic
    I have a problem with detecting collision between 2 models using BoundingSpheres in XNA 4.0. The code I'm using i very simple: private bool IsCollision(Model model1, Matrix world1, Model model2, Matrix world2) { for (int meshIndex1 = 0; meshIndex1 < model1.Meshes.Count; meshIndex1++) { BoundingSphere sphere1 = model1.Meshes[meshIndex1].BoundingSphere; sphere1 = sphere1.Transform(world1); for (int meshIndex2 = 0; meshIndex2 < model2.Meshes.Count; meshIndex2++) { BoundingSphere sphere2 = model2.Meshes[meshIndex2].BoundingSphere; sphere2 = sphere2.Transform(world2); if (sphere1.Intersects(sphere2)) return true; } } return false; } The problem I'm getting is that when I call this method from the Update method, the program behaves as if this method always returns true value (which of course is not correct). The code for calling is very simple (although this is only the test code): if (IsCollision(model1, worldModel1, model2, worldModel2)) { Window.Title = "Intersects"; } What is causing this?

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  • Interesting 3d zooming technique

    - by stark
    Is it possible to zoom to a certain point on screen by modifying the field of view and rotating the camera as to keep that point/object in the same place on screen while zooming ? Changing the camera position is not allowed.. I projected the 3d pos of the object on screen and remembered it. Then on each frame I calculate the direction to it in camera space and then I construct a rotation matrix to align this direction to Z axis (in cam space). After this, I calculate the direction from the camera to the object in world space and transform this vector with the matrix I obtained earlier and then use this final vector as the camera's new direction. And it's actually "kinda working", the problem is that it is more/less off than the camera's rotation before starting to zoom depending on the area you are trying to zoom in (larger error on edges/corners). It looks acceptable, but I'm not settling for only this. Any suggestions/resources for doing this technique perfectly ? If some of you want to explain the math in detail, be my guests, I can understand these things well. Thanks. Edit: I'll check often for responses, I'm really curious about this :D

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  • Moviebarcodes Showcases Entire Movies as Frame-based Barcodes

    - by Jason Fitzpatrick
    If you’ve ever wanted a chance to look at at an entire movie in a single glance, here’s your chance. Moviebarcodes shares mock-barcodes generated by turning each frame of a movie into a thin stripe, offering a glimpse into the color choices and shot lengths in popular movies. The barcode seen above was generated from The Matrix; you can see where the green indicates scenes that were shot inside the matrix and thus given a subtle green tint. In the barcode below, generated from the movie Pleasantville you can see the transition in the movie between the color and black and white scenes. In the case of Pleasantville, elements of the black and white world turning to color represent pivotal moments in the plot development which are now neatly mapped out below: Check out the hundreds of barcodes at the link below; you can even order prints of your favorite movies. Find a great rendering in the mix? Share a link in the comments below. Moviebarcodes [via Cool Inforgraphics] How to Create an Easy Pixel Art Avatar in Photoshop or GIMPInternet Explorer 9 Released: Here’s What You Need To KnowHTG Explains: How Does Email Work?

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