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  • Last Observation Carried Forward In a data frame?

    - by Tal Galili
    Hi all, I wish to implement a "Last Observation Carried Forward" for a data set I am working on which has missing values at the end of it. Here is a simple code to do it (question after it): LOCF <- function(x) { # Last Observation Carried Forward (for a left to right series) LOCF <- max(which(!is.na(x))) # the location of the Last Observation to Carry Forward x[LOCF:length(x)] <- x[LOCF] return(x) } # example: LOCF(c(1,2,3,4,NA,NA)) LOCF(c(1,NA,3,4,NA,NA)) Now this works great for simple vectors. But if I where to try and use it on a data frame: a <- data.frame(rep("a",4), 1:4,1:4, c(1,NA,NA,NA)) a t(apply(a, 1, LOCF)) # will make a mess It will turn my data frame into a character matrix. Can you think of a way to do LOCF on a data.frame, without turning it into a matrix? (I could use loops and such to correct the mess, but would love for a more elegant solution) Cheers, Tal

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  • How to access a matrix in a matlab struct's field from a mex function?

    - by B. Ruschill
    I'm trying to figure out how to access a matrix that is stored in a field in a matlab structure from a mex function. That's awfully long winded... Let me explain: I have a matlab struct that was defined like the following: matrixStruct = struct('matrix', {4, 4, 4; 5, 5, 5; 6, 6 ,6}) I have a mex function in which I would like to be able to receive a pointer to the first element in the matrix (matrix[0][0], in c terms), but I've been unable to figure out how to do that. I have tried the following: /* Pointer to the first element in the matrix (supposedly)... */ double *ptr = mxGetPr(mxGetField(prhs[0], 0, "matrix"); /* Incrementing the pointer to access all values in the matrix */ for(i = 0; i < 3; i++){ printf("%f\n", *(ptr + (i * 3))); printf("%f\n", *(ptr + 1 + (i * 3))); printf("%f\n", *(ptr + 2 + (i * 3))); } What this ends up printing is the following: 4.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 I have also tried variations of the following, thinking that perhaps it was something wonky with nested function calls, but to no avail: /* Pointer to the first location of the mxArray */ mxArray *fieldValuePtr = mxGetField(prhs[0], 0, "matrix"); /* Get the double pointer to the first location in the matrix */ double *ptr = mxGetPr(fieldValuePtr); /* Same for loop code here as written above */ Does anyone have an idea as to how I can achieve what I'm trying to, or what I am potentially doing wrong? Thanks! Edit: As per yuk's comment, I tried doing similar operations on a struct that has a field called array which is a one-dimensional array of doubles. The struct containing the array is defined as follows: arrayStruct = struct('array', {4.44, 5.55, 6.66}) I tried the following on the arrayStruct from within the mex function: mptr = mxGetPr(mxGetField(prhs[0], 0, "array")); printf("%f\n", *(mptr)); printf("%f\n", *(mptr + 1)); printf("%f\n", *(mptr + 2)); ...but the output followed what was printed earlier: 4.440000 0.000000 0.000000

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  • Finding matching submatrics inside a matrix

    - by DaveO
    I have a 100x200 2D array expressed as a numpy array consisting of black (0) and white (255) cells. It is a bitmap file. I then have 2D shapes (it's easiest to think of them as letters) that are also 2D black and white cells. I know I can naively iterate through the matrix but this is going to be a 'hot' portion of my code so speed is an concern. Is there a fast way to perform this in numpy/scipy? I looked briefly at Scipy's correlate function. I am not interested in 'fuzzy matches', only exact matches. I also looked at some academic papers but they are above my head.

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  • O'Reilly book clarification on 2d linear system

    - by Eric
    The Oreilly book "Learning openCV" states at page 356 : Quote Before we get totally lost, let’s consider a particular realistic situation of taking measurements on a car driving in a parking lot. We might imagine that the state of the car could be summarized by two position variables, x and y, and two velocities, vx and vy. These four variables would be the elements of the state vector xk. Th is suggests that the correct form for F is: x = [ x; y; vx; vy; ]k F = [ 1, 0, dt, 0; 0, 1, 0, dt; 0, 0, 1, 0; 0, 0, 0, 1; ] It seems natural to put 'dt' just there in the F matrix but I just don't get why. What if I have a n states system, how would I spray some "dt" in the F matrix?

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  • Multiplying Block Matrices in Numpy

    - by Ada Xu
    Hi Everyone I am python newbie I have to implement lasso L1 regression for a class assignment. This involves solving a quadratic equation involving block matrices. minimize x^t * H * x + f^t * x where x 0 Where H is a 2 X 2 block matrix with each element being a k dimensional matrix and x and f being a 2 X 1 vectors each element being a k dimension vector. I was thinking of using nd arrays. such that np.shape(H) = (2, 2, k, k) np.shape(x) = (2, k) But I figured out that np.dot(X, H) doesn't work here. Is there an easy way to solve this problem? Thanks in advance.

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  • JAVA. Writing a matrix in a file using column information.

    - by Dmitry
    Hello, everybody! I have a file in which a matrix is stored. This file has a RandomAccessFile type. This matrix is stored by columns. I mean that in an i-th row of this matrix an i-th column (of a real matrix) is stored. There is an example: i-th row: 1 2 3 4 (in the file). That means that the real matrix has an i-th column: (1 2 3 4)(transpose). I need to save this matrix in natural way (by rows) in a new file, which I will then open with FileReader and display with TestArea. DO you know, how to do that? If so, please help =)

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  • Reading Matrices in MATLAB and assigning coordinates to the entries

    - by Michael Schofield
    Hi, I'm a bit new to MATLAB. Basically, I have a 25x25 Matrix, complete with various random entries ranging from 0 to 3. I need to write a program that reads this matrix, and assigns x-y coordinates to the entries, so that when I ask for an input of a particular x-y coordinate which has, say an entry of 3, then it will result in an error. I'm a bit overwhelmed - but I understand the general concept of what I'm supposed to be finding. I'm wondering if I should use a plot instead to help me.

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  • Generate matrix with value flags

    - by pagid
    I do have a solution for the following problem but it's quite ugly and it can most likely be done in a much shorter way. Would be great to get your help. My input looks like this: C1 C2 A B B D D C A D and my output should look like this: A B C D 1 1 0 0 0 1 0 1 0 0 1 1 1 0 0 1 My current solution is: index <- unique(unlist(input[,1:2])) output <- matrix(0,nrows=dim(input),ncols=length(index)) for(i in 1:dim(input)) { output[i, input[i,]$C1] <- 1 output[i, input[i,]$C2] <- 1 } Of course 4-5 lines is actually fine - but even as an R beginner this doesn't feel right to use a for loop. Besides that my actual data has much more than two columns, therefore this doesn't look nice in the end. How would I do that in a smarter way? Cheers

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  • Help me to explain the F# Matrix transpose function

    - by Kev
    There is a Matrix transpose function: let rec transpose = function | (_::_)::_ as M -> List.map List.head M :: transpose (List.map List.tail M) | _ -> [] [[1; 2; 3]; [4; 5; 6]; [7; 8; 9]] |> transpose |> printfn "%A" It works fine. What does ( _ :: _ ) :: _ mean? I don't understand the whole code! Who can explain it? Thank You!

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  • How to store matrix information in MySQL?

    - by dedalo
    Hi, I'm working on an application that analizes music similarity. In order to do that I proccess audio data and store the results in txt files. For each audio file I create 2 files, 1 containing and 16 values (each value can be like this:2.7000023942731723) and the other file contains 16 rows, each row containing 16 values like the one previously shown. I'd like to store the contents of these 2 file in a table of my MySQL database. My table looks like: Name varchar(100) Author varchar (100) in order to add the content of those 2 file I think I need to use the BLOB data type: file1 blob file2 blob My question is how should I store this info in the data base? I'm working with Java where I have a double array containing the 16 values (for the file1) and a matrix containing the file2 info. Should I process the values as strings and add them to the columns in my database? Thanks

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  • How to calculate the state of a graph?

    - by zcb
    Given a graph G=(V,E), each node i is associated with 'Ci' number of objects. At each step, for every node i, the Ci objects will be taken away by the neighbors of i equally. After K steps, output the number of objects of the top five nodes which has the most objects. Some Constrains: |V|<10^5, |E|<2*10^5, K<10^7, Ci<1000 My current idea is: represent the transformation in each step with a matrix. This problem is converted to the calculation of the power of matrix. But this solution is much too slow considering |V| can be 10^5. Is there any faster way to do it?

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  • passing a float as a pointer to a matrix

    - by numerical25
    Honestly, I couldnt think of a better title for this issue because I am having 2 problems and I don't know the cause. The first problem I have is this //global declaration float g_posX = 0.0f; ............. //if keydown happens g_posX += 0.03f; &m_mtxView._41 = g_posX; I get this error cannot convert from 'float' to 'float *' So I assume that the matrix only accepts pointers. So i change the varible to this.... //global declaration float *g_posX = 0.0f; ............. //if keydown happens g_posX += 0.03f; &m_mtxView._41 = &g_posX; and I get this error cannot convert from 'float' to 'float *' which is pretty much saying that I can not declare g_posX as a pointer. honestly, I don't know what to do.

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  • I want to make a wrapped acces type for certain internals of one of classes and I have some performa

    - by Alex
    I am writing an abstract matrix class (and some concrete subclasses) for use on very differing hardwares/architectures, etc. and I want to write a row and column type that provides a transparent reference to the rows and columns of the matrix. However, I want to tune for performance, so I'd like this class to be essentially a compiler construct. In other words, I'm willing to sacrifice some dev time to making the overhead of these classes as small as possible. I assume all (small) methods would want to be virtual? Keep the structure small? Any other suggestions?

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  • XNA 3D model collision is inaccurate

    - by Daniel Lopez
    I am creating a classic game in 3d that deals with asteriods and you have to shoot them and avoid being hit from them. I can generate the asteroids just fine and the ship can shoot bullets just fine. But the asteroids always hit the ship even it doesn't look they are even close. I know 2D collision very well but not 3D so can someone please shed some light to my problem. Thanks in advance. Code For ModelRenderer: using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; namespace _3D_Asteroids { class ModelRenderer { private float aspectratio; private Model model; private Vector3 camerapos; private Vector3 modelpos; private Matrix rotationy; float radiansy = 0; private bool isalive; public ModelRenderer(Model m, float AspectRatio, Vector3 initial_pos, Vector3 initialcamerapos) { isalive = true; model = m; if (model.Meshes.Count == 0) { throw new Exception("Invalid model because it contains zero meshes!"); } modelpos = initial_pos; camerapos = initialcamerapos; aspectratio = AspectRatio; return; } public float RadiusOfSphere { get { return model.Meshes[0].BoundingSphere.Radius; } } public BoundingBox BoxBounds { get { return BoundingBox.CreateFromSphere(model.Meshes[0].BoundingSphere); } } public BoundingSphere SphereBounds { get { return model.Meshes[0].BoundingSphere; } } public Vector3 CameraPosition { set { camerapos = value; } get { return camerapos; } } public bool IsAlive { get { return isalive; } } public Vector3 ModelPosition { set { modelpos = value; } get { return modelpos; } } public void RotateY(float radians) { radiansy += radians; rotationy = Matrix.CreateRotationY(radiansy); } public Matrix RotationY { set { rotationy = value; } get { return rotationy; } } public float AspectRatio { set { aspectratio = value; } get { return aspectratio; } } public void Kill() { isalive = false; } public void Draw(float scale) { Matrix world; if (rotationy == new Matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)) { world = Matrix.CreateScale(scale) * Matrix.CreateTranslation(modelpos); } else { world = rotationy * Matrix.CreateScale(scale) * Matrix.CreateTranslation(modelpos); } Matrix view = Matrix.CreateLookAt(camerapos, Vector3.Zero, Vector3.Up); Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45.0f), this.AspectRatio, 1f, 100000f); foreach (ModelMesh mesh in model.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.World = world; effect.View = view; effect.Projection = projection; } mesh.Draw(); } } public void Draw() { Matrix world; if (rotationy == new Matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)) { world = Matrix.CreateTranslation(modelpos); } else { world = rotationy * Matrix.CreateTranslation(modelpos); } Matrix view = Matrix.CreateLookAt(camerapos, Vector3.Zero, Vector3.Up); Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45.0f), this.AspectRatio, 1f, 100000f); foreach (ModelMesh mesh in model.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.World = world; effect.View = view; effect.Projection = projection; } mesh.Draw(); } } } Code For Game1: using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; namespace _3D_Asteroids { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; int score = 0, lives = 5; SpriteBatch spriteBatch; GameState gstate = GameState.OnMenuScreen; Menu menu = new Menu(Color.Yellow, Color.White); SpriteFont font; Texture2D background; ModelRenderer ship; Model b, a; List<ModelRenderer> bullets = new List<ModelRenderer>(); List<ModelRenderer> asteriods = new List<ModelRenderer>(); float time = 0.0f; int framecount = 0; SoundEffect effect; public Game1() { graphics = new GraphicsDeviceManager(this); graphics.PreferredBackBufferWidth = 1280; graphics.PreferredBackBufferHeight = 796; graphics.ApplyChanges(); Content.RootDirectory = "Content"; } /// <summary> /// Allows the game to perform any initialization it needs to before starting to run. /// This is where it can query for any required services and load any non-graphic /// related content. Calling base.Initialize will enumerate through any components /// and initialize them as well. /// </summary> protected override void Initialize() { // TODO: Add your initialization logic here base.Initialize(); } /// <summary> /// LoadContent will be called once per game and is the place to load /// all of your content. /// </summary> protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); font = Content.Load<SpriteFont>("Fonts\\Lucida Console"); background = Content.Load<Texture2D>("Textures\\B1_stars"); Model p1 = Content.Load<Model>("Models\\p1_wedge"); b = Content.Load<Model>("Models\\pea_proj"); a = Content.Load<Model>("Models\\asteroid1"); effect = Content.Load<SoundEffect>("Audio\\tx0_fire1"); ship = new ModelRenderer(p1, GraphicsDevice.Viewport.AspectRatio, new Vector3(0, 0, 0), new Vector3(0, 0, 9000)); } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { } /// <summary> /// Allows the game to run logic such as updating the world, /// checking for collisions, gathering input, and playing audio. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Update(GameTime gameTime) { KeyboardState state = Keyboard.GetState(PlayerIndex.One); switch (gstate) { case GameState.OnMenuScreen: { if (state.IsKeyDown(Keys.Enter)) { switch (menu.SelectedChoice) { case MenuChoices.Play: { gstate = GameState.GameStarted; break; } case MenuChoices.Exit: { this.Exit(); break; } } } if (state.IsKeyDown(Keys.Down)) { menu.MoveSelectedMenuChoiceDown(gameTime); } else if(state.IsKeyDown(Keys.Up)) { menu.MoveSelectedMenuChoiceUp(gameTime); } else { menu.KeysReleased(); } break; } case GameState.GameStarted: { foreach (ModelRenderer bullet in bullets) { if (bullet.ModelPosition.X < (ship.ModelPosition.X + 4000) && bullet.ModelPosition.Z < (ship.ModelPosition.X + 4000) && bullet.ModelPosition.X > (ship.ModelPosition.Z - 4000) && bullet.ModelPosition.Z > (ship.ModelPosition.Z - 4000)) { bullet.ModelPosition += (bullet.RotationY.Forward * 120); } else if (collidedwithasteriod(bullet)) { bullet.Kill(); } else { bullet.Kill(); } } foreach (ModelRenderer asteroid in asteriods) { if (ship.SphereBounds.Intersects(asteroid.BoxBounds)) { lives -= 1; asteroid.Kill(); // This always hits no matter where the ship goes. } else { asteroid.ModelPosition -= (asteroid.RotationY.Forward * 50); } } for (int index = 0; index < asteriods.Count; index++) { if (asteriods[index].IsAlive == false) { asteriods.RemoveAt(index); } } for (int index = 0; index < bullets.Count; index++) { if (bullets[index].IsAlive == false) { bullets.RemoveAt(index); } } if (state.IsKeyDown(Keys.Left)) { ship.RotateY(0.1f); if (state.IsKeyDown(Keys.Space)) { if (time < 17) { firebullet(); //effect.Play(); } } else { time = 0; } } else if (state.IsKeyDown(Keys.Right)) { ship.RotateY(-0.1f); if (state.IsKeyDown(Keys.Space)) { if (time < 17) { firebullet(); //effect.Play(); } } else { time = 0; } } else if (state.IsKeyDown(Keys.Up)) { ship.ModelPosition += (ship.RotationY.Forward * 50); if (state.IsKeyDown(Keys.Space)) { if (time < 17) { firebullet(); //effect.Play(); } } else { time = 0; } } else if (state.IsKeyDown(Keys.Space)) { time += gameTime.ElapsedGameTime.Milliseconds; if (time < 17) { firebullet(); //effect.Play(); } } else { time = 0.0f; } if ((framecount % 60) == 0) { createasteroid(); framecount = 0; } framecount++; break; } } base.Update(gameTime); } void firebullet() { if (bullets.Count < 3) { ModelRenderer bullet = new ModelRenderer(b, GraphicsDevice.Viewport.AspectRatio, ship.ModelPosition, new Vector3(0, 0, 9000)); bullet.RotationY = ship.RotationY; bullets.Add(bullet); } } void createasteroid() { if (asteriods.Count < 2) { Random random = new Random(); float z = random.Next(-13000, -11000); float x = random.Next(-9000, -8000); Random random2 = new Random(); int degrees = random.Next(0, 45); float radians = MathHelper.ToRadians(degrees); ModelRenderer asteroid = new ModelRenderer(a, GraphicsDevice.Viewport.AspectRatio, new Vector3(x, 0, z), new Vector3(0,0, 9000)); asteroid.RotateY(radians); asteriods.Add(asteroid); } } /// <summary> /// This is called when the game should draw itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); switch (gstate) { case GameState.OnMenuScreen: { spriteBatch.Begin(); spriteBatch.Draw(background, Vector2.Zero, Color.White); menu.DrawMenu(ref spriteBatch, font, new Vector2(GraphicsDevice.Viewport.Width / 2, GraphicsDevice.Viewport.Height / 2) - new Vector2(50f), 100f); spriteBatch.End(); break; } case GameState.GameStarted: { spriteBatch.Begin(); spriteBatch.Draw(background, Vector2.Zero, Color.White); spriteBatch.DrawString(font, "Score: " + score.ToString() + "\nLives: " + lives.ToString(), Vector2.Zero, Color.White); spriteBatch.End(); ship.Draw(); foreach (ModelRenderer bullet in bullets) { bullet.Draw(); } foreach (ModelRenderer asteroid in asteriods) { asteroid.Draw(0.1f); } break; } } base.Draw(gameTime); } bool collidedwithasteriod(ModelRenderer bullet) { foreach (ModelRenderer asteroid in asteriods) { if (bullet.SphereBounds.Intersects(asteroid.BoxBounds)) { score += 10; asteroid.Kill(); return true; } } return false; } } } }

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  • Problem with memset after an instance of a user defined class is created and a file is opened

    - by Liberalkid
    I'm having a weird problem with memset, that was something to do with a class I'm creating before it and a file I'm opening in the constructor. The class I'm working with normally reads in an array and transforms it into another array, but that's not important. The class I'm working with is: #include <vector> #include <algorithm> using namespace std; class PreProcess { public: PreProcess(char* fileName,char* outFileName); void SortedOrder(); private: vector< vector<double > > matrix; void SortRow(vector<double> &row); char* newFileName; vector< pair<double,int> > rowSorted; }; The other functions aren't important, because I've stopped calling them and the problem persists. Essentially I've narrowed it down to my constructor: PreProcess::PreProcess(char* fileName,char* outFileName):newFileName(outFileName){ ifstream input(fileName); input.close(); //this statement is inconsequential } I also read in the file in my constructor, but I've found that the problem persists if I don't read in the matrix and just open the file. Essentially I've narrowed it down to if I comment out those two lines the memset works properly, otherwise it doesn't. Now to the context of the problem I'm having with it: I wrote my own simple wrapper class for matrices. It doesn't have much functionality, I just need 2D arrays in the next part of my project and having a class handle everything makes more sense to me. The header file: #include <iostream> using namespace std; class Matrix{ public: Matrix(int r,int c); int &operator()(int i,int j) {//I know I should check my bounds here return matrix[i*columns+j]; } ~Matrix(); const void Display(); private: int *matrix; const int rows; const int columns; }; Driver: #include "Matrix.h" #include <string> using namespace std; Matrix::Matrix(int r,int c):rows(r),columns(c) { matrix=new int[rows*columns]; memset(matrix,0,sizeof(matrix)); } const void Matrix::Display(){ for(int i=0;i<rows;i++){ for(int j=0;j<columns;j++) cout << (*this)(i,j) << " "; cout << endl; } } Matrix::~Matrix() { delete matrix; } My main program runs: PreProcess test1(argv[1],argv[2]); //test1.SortedOrder(); Matrix test(10,10); test.Display(); And when I run this with the input line uncommented I get: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1371727776 32698 -1 0 0 0 0 0 6332656 0 -1 -1 0 0 6332672 0 0 0 0 0 0 0 0 0 0 0 0 0 -1371732704 32698 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 I really don't have a clue what's going on in memory to cause this, on a side note if I replace memset with: for(int i=0;i<rows*columns;i++) *(matrix+i) &= 0x0; Then it works perfectly, it also works if I don't open the file. If it helps I'm running GCC 64-bit version 4.2.4 on Ubuntu.I assume there's some functionality of memset that I'm not properly understanding.

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  • SQL Query for generating matrix like output querying related table in SQL Server

    - by Nagesh
    I have three tables: Product ProductID ProductName 1 Cycle 2 Scooter 3 Car Customer CustomerID CustomerName 101 Ronald 102 Michelle 103 Armstrong 104 Schmidt 105 Peterson Transactions TID ProductID CustomerID TranDate Amount 10001 1 101 01-Jan-11 25000.00 10002 2 101 02-Jan-11 98547.52 10003 1 102 03-Feb-11 15000.00 10004 3 102 07-Jan-11 36571.85 10005 2 105 09-Feb-11 82658.23 10006 2 104 10-Feb-11 54000.25 10007 3 103 20-Feb-11 80115.50 10008 3 104 22-Feb-11 45000.65 I have written a query to group the transactions like this: SELECT P.ProductName AS Product, C.CustName AS Customer, SUM(T.Amount) AS Amount FROM Transactions AS T INNER JOIN Product AS P ON T.ProductID = P.ProductID INNER JOIN Customer AS C ON T.CustomerID = C.CustomerID WHERE T.TranDate BETWEEN '2011-01-01' AND '2011-03-31' GROUP BY P.ProductName, C.CustName ORDER BY P.ProductName which gives the result like this: Product Customer Amount Car Armstrong 80115.50 Car Michelle 36571.85 Car Schmidt 45000.65 Cycle Michelle 15000.00 Cycle Ronald 25000.00 Scooter Peterson 82658.23 Scooter Ronald 98547.52 Scooter Schmidt 54000.25 I need result of query in MATRIX form like this: Customer |------------ Amounts --------------- Name |Car Cycle Scooter Totals Armstrong 80115.50 0.00 0.00 80115.50 Michelle 36571.85 15000.00 0.00 51571.85 Ronald 0.00 25000.00 98547.52 123547.52 Peterson 0.00 0.00 82658.23 82658.23 Schmidt 45000.65 0.00 54000.25 99000.90 Please help me to acheive the above result in SQL Server 2005. Using mulitple views or even temporory tables is fine for me.

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  • FFT and IFFT on 3D matrix (Matlab)

    - by SteffenDM
    I have a movie with 70 grayscale frames in MATLAB. I have put them in a 3-D matrix, so the dimensions are X, Y and time. I want to determine the frequencies in the time dimension, so I have to calculate the FFT for every point in the 3rd dimension. This is not a problem but I have to return the images to the original form with ifft. In a normal situation this would be true: X = ifft(fft(X)), but this is not the case it seems in MATLAB when you work with multidimensional data. This is the code I use: for i = 1:length y(:, :, i) = [img1{i, level}]; %# take each picture from an cell array and put it end %# and put it in 3D array y2 = ifft(fft(y, NFFT,3), NFFT, 3); %# NFFT = 128, the 3 is the dimension in which i want %# to calculate the FFT and IFFT y is 480x640x70, so there are 70 images of 640x480 pixels. If I use only fft, y2 is 480x640x128 (this is normal because we want 128 points with NFFT). If I use fft and ifft, y2 is 480x640x128 pixels. This is not normal, the 128 should be 70 again. I tried to do it in just one dimension by using 2 for loops and this works fine. The for loops take to much time, though.

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  • Memory allocation for a matrix in C

    - by Snogzvwtr
    Why is the following code resulting in Segmentation fault? (I'm trying to create two matrices of the same size, one with static and the other with dynamic allocation) #include <stdio.h> #include <stdlib.h> //Segmentation fault! int main(){ #define X 5000 #define Y 6000 int i; int a[X][Y]; int** b = (int**) malloc(sizeof(int*) * X); for(i=0; i<X; i++){ b[i] = malloc (sizeof(int) * Y); } } Weirdly enough, if I comment out one of the matrix definitions, the code runs fine. Like this: #include <stdio.h> #include <stdlib.h> //No Segmentation fault! int main(){ #define X 5000 #define Y 6000 int i; //int a[X][Y]; int** b = (int**) malloc(sizeof(int*) * X); for(i=0; i<X; i++){ b[i] = malloc (sizeof(int) * Y); } } or #include <stdio.h> #include <stdlib.h> //No Segmentation fault! int main(){ #define X 5000 #define Y 6000 int i; int a[X][Y]; //int** b = (int**) malloc(sizeof(int*) * X); //for(i=0; i<X; i++){ // b[i] = malloc (sizeof(int) * Y); //} } I'm running gcc on Linux on a 32-bit machine.

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  • Set all nonzero matrix elements to 1 (while keeping the others 0)

    - by Tomas Lycken
    I have a mesh grid defined as [X, Y, Z] = meshgrid(-100:100, -100:100, 25); % z will have more values later and two shapes (ovals, in this case): x_offset_1 = 40; x_offset_2 = -x_offset_1; o1 = ((X-x_offset_1).^2./(2*Z).^2+Y.^2./Z.^2 <= 1); o2 = ((X-x_offset_2).^2./(2*Z).^2+Y.^2./Z.^2 <= 1); Now, I want to find all points that are nonzero in either oval. I tried union = o1+o2; but since I simply add them, the overlapping region will have a value of 2 instead of the desired 1. How can I set all nonzero entries in the matrix to 1, regardless of their previous value? (I tried normalized_union = union./union;, but then I end up with NaN in all 0 elements because I'm dividing by zero...) Follow-up question: I got a perfect answer to my original question, but now I have a follow-up question on the same problem. I'm going to define a filled disc, c = (X.^2+Y.^2<R^2) that will also overlap with the two ovals. How do I find all the points that are inside the circle, but not inside any of the ovals?

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  • How do I make A* check all diagonal and orthogonal directions?

    - by Munezane
    I'm making a turn-based tactical game and I'm trying to implement the A* algorithm. I've been following a tutorial and got to this point, but my characters can't move diagonally up and left. Can anyone help me with this? The return x and y are int pointers which the characters are using to move towards the target. void level::aStar(int startx, int starty, int targetx, int targety, int* returnx, int* returny) { aStarGridSquare* currentSquare = new aStarGridSquare(); aStarGridSquare* startSquare = new aStarGridSquare(); aStarGridSquare* targetSquare = new aStarGridSquare(); aStarGridSquare* adjacentSquare = new aStarGridSquare(); aStarOpenList.clear(); for(unsigned int i=0; i<aStarGridSquareList.size(); i++) { aStarGridSquareList[i]->open=false; aStarGridSquareList[i]->closed=false; } startSquare=getaStarGridSquare(startx, starty); targetSquare=getaStarGridSquare(targetx, targety); if(startSquare==targetSquare) { *returnx=startx; *returny=starty; return; } startSquare->CostFromStart=0; startSquare->CostToTraverse=0; startSquare->parent = NULL; currentSquare=startSquare; aStarOpenList.push_back(currentSquare); while(currentSquare!=targetSquare && aStarOpenList.size()>0) { //unsigned int totalCostEstimate=aStarOpenList[0]->TotalCostEstimate; //currentSquare=aStarOpenList[0]; for(unsigned int i=0; i<aStarOpenList.size(); i++) { if(aStarOpenList.size()>1) { for(unsigned int j=1; j<aStarOpenList.size()-1; j++) { if(aStarOpenList[i]->TotalCostEstimate<aStarOpenList[j]->TotalCostEstimate) { currentSquare=aStarOpenList[i]; } else { currentSquare=aStarOpenList[j]; } } } else { currentSquare = aStarOpenList[i]; } } currentSquare->closed=true; currentSquare->open=false; for(unsigned int i=0; i<aStarOpenList.size(); i++) { if(aStarOpenList[i]==currentSquare) { aStarOpenList.erase(aStarOpenList.begin()+i); } } for(unsigned int i = currentSquare->blocky - 32; i <= currentSquare->blocky + 32; i+=32) { for(unsigned int j = currentSquare->blockx - 32; j<= currentSquare->blockx + 32; j+=32) { adjacentSquare=getaStarGridSquare(j/32, i/32); if(adjacentSquare!=NULL) { if(adjacentSquare->blocked==false && adjacentSquare->closed==false) { if(adjacentSquare->open==false) { adjacentSquare->parent=currentSquare; if(currentSquare->parent!=NULL) { currentSquare->CostFromStart = currentSquare->parent->CostFromStart + currentSquare->CostToTraverse + startSquare->CostFromStart; } else { currentSquare->CostFromStart=0; } adjacentSquare->CostFromStart =currentSquare->CostFromStart + adjacentSquare->CostToTraverse;// adjacentSquare->parent->CostFromStart + adjacentSquare->CostToTraverse; //currentSquare->CostToEndEstimate = abs(currentSquare->blockx - targetSquare->blockx) + abs(currentSquare->blocky - targetSquare->blocky); //currentSquare->TotalCostEstimate = currentSquare->CostFromStart + currentSquare->CostToEndEstimate; adjacentSquare->open = true; adjacentSquare->CostToEndEstimate=abs(adjacentSquare->blockx- targetSquare->blockx) + abs(adjacentSquare->blocky-targetSquare->blocky); adjacentSquare->TotalCostEstimate = adjacentSquare->CostFromStart+adjacentSquare->CostToEndEstimate; //adjacentSquare->open=true;*/ aStarOpenList.push_back(adjacentSquare); } else { if(adjacentSquare->parent->CostFromStart > currentSquare->CostFromStart) { adjacentSquare->parent=currentSquare; if(currentSquare->parent!=NULL) { currentSquare->CostFromStart = currentSquare->parent->CostFromStart + currentSquare->CostToTraverse + startSquare->CostFromStart; } else { currentSquare->CostFromStart=0; } adjacentSquare->CostFromStart =currentSquare->CostFromStart + adjacentSquare->CostToTraverse;// adjacentSquare->parent->CostFromStart + adjacentSquare->CostToTraverse; //currentSquare->CostToEndEstimate = abs(currentSquare->blockx - targetSquare->blockx) + abs(currentSquare->blocky - targetSquare->blocky); //currentSquare->TotalCostEstimate = currentSquare->CostFromStart + currentSquare->CostToEndEstimate; adjacentSquare->CostFromStart = adjacentSquare->parent->CostFromStart + adjacentSquare->CostToTraverse; adjacentSquare->CostToEndEstimate=abs(adjacentSquare->blockx - targetSquare->blockx) + abs(adjacentSquare->blocky - targetSquare->blocky); adjacentSquare->TotalCostEstimate = adjacentSquare->CostFromStart+adjacentSquare->CostToEndEstimate; } } } } } } } if(aStarOpenList.size()==0)//if empty { *returnx =startx; *returny =starty; return; } else { for(unsigned int i=0; i< aStarOpenList.size(); i++) { if(currentSquare->parent==NULL) { //int tempX = targetSquare->blockx; //int tempY = targetSquare->blocky; *returnx=targetSquare->blockx; *returny=targetSquare->blocky; break; } else { currentSquare=currentSquare->parent; } } } }

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  • Join and sum not compatible matrices through data.table

    - by leodido
    My goal is to "sum" two not compatible matrices (matrices with different dimensions) using (and preserving) row and column names. I've figured this approach: convert the matrices to data.table objects, join them and then sum columns vectors. An example: > M1 1 3 4 5 7 8 1 0 0 1 0 0 0 3 0 0 0 0 0 0 4 1 0 0 0 0 0 5 0 0 0 0 0 0 7 0 0 0 0 1 0 8 0 0 0 0 0 0 > M2 1 3 4 5 8 1 0 0 1 0 0 3 0 0 0 0 0 4 1 0 0 0 0 5 0 0 0 0 0 8 0 0 0 0 0 > M1 %ms% M2 1 3 4 5 7 8 1 0 0 2 0 0 0 3 0 0 0 0 0 0 4 2 0 0 0 0 0 5 0 0 0 0 0 0 7 0 0 0 0 1 0 8 0 0 0 0 0 0 This is my code: M1 <- matrix(c(0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0), byrow = TRUE, ncol = 6) colnames(M1) <- c(1,3,4,5,7,8) M2 <- matrix(c(0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0), byrow = TRUE, ncol = 5) colnames(M2) <- c(1,3,4,5,8) # to data.table objects DT1 <- data.table(M1, keep.rownames = TRUE, key = "rn") DT2 <- data.table(M2, keep.rownames = TRUE, key = "rn") # join and sum of common columns if (nrow(DT1) > nrow(DT2)) { A <- DT2[DT1, roll = TRUE] A[, list(X1 = X1 + X1.1, X3 = X3 + X3.1, X4 = X4 + X4.1, X5 = X5 + X5.1, X7, X8 = X8 + X8.1), by = rn] } That outputs: rn X1 X3 X4 X5 X7 X8 1: 1 0 0 2 0 0 0 2: 3 0 0 0 0 0 0 3: 4 2 0 0 0 0 0 4: 5 0 0 0 0 0 0 5: 7 0 0 0 0 1 0 6: 8 0 0 0 0 0 0 Then I can convert back this data.table to a matrix and fix row and column names. The questions are: how to generalize this procedure? I need a way to automatically create list(X1 = X1 + X1.1, X3 = X3 + X3.1, X4 = X4 + X4.1, X5 = X5 + X5.1, X7, X8 = X8 + X8.1) because i want to apply this function to matrices which dimensions (and row/columns names) are not known in advance. In summary I need a merge procedure that behaves as described. there are other strategies/implementations that achieve the same goal that are, at the same time, faster and generalized? (hoping that some data.table monster help me) to what kind of join (inner, outer, etc. etc.) is assimilable this procedure? Thanks in advance. p.s.: I'm using data.table version 1.8.2 EDIT - SOLUTIONS @Aaron solution. No external libraries, only base R. It works also on list of matrices. add_matrices_1 <- function(...) { a <- list(...) cols <- sort(unique(unlist(lapply(a, colnames)))) rows <- sort(unique(unlist(lapply(a, rownames)))) out <- array(0, dim = c(length(rows), length(cols)), dimnames = list(rows,cols)) for (m in a) out[rownames(m), colnames(m)] <- out[rownames(m), colnames(m)] + m out } @MadScone solution. Used reshape2 package. It works only on two matrices per call. add_matrices_2 <- function(m1, m2) { m <- acast(rbind(melt(M1), melt(M2)), Var1~Var2, fun.aggregate = sum) mn <- unique(colnames(m1), colnames(m2)) rownames(m) <- mn colnames(m) <- mn m } BENCHMARK (100 runs with microbenchmark package) Unit: microseconds expr min lq median uq max 1 add_matrices_1 196.009 257.5865 282.027 291.2735 549.397 2 add_matrices_2 13737.851 14697.9790 14864.778 16285.7650 25567.448 No need to comment the benchmark: @Aaron solution wins. I'll continue to investigate a similar solution for data.table objects. I'll add other solutions eventually reported or discovered.

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  • Converting switch statements to more elegant solution.

    - by masfenix
    I have a 9 x 9 matrix. (think of suduko). 4 2 1 6 8 1 8 5 8 3 1 5 8 1 1 7 5 8 1 1 4 0 5 6 7 0 4 6 2 5 5 4 4 8 1 2 6 8 8 2 8 1 6 3 5 8 4 2 6 4 7 4 1 1 1 3 5 3 8 8 5 2 2 2 6 6 0 8 8 8 0 6 8 7 2 3 3 1 1 7 4 now I wanna be able to get a "quadrant". for example (according to my code) the quadrant 2 , 2 returns the following: 5 4 4 2 8 1 6 4 7 If you've noticed, this is the matrix from the very center of the 9 x 9. I've split everything up in to pairs of "3" if you know what i mean. the first "ROW" is from 0 - 3, the second from 3 - 6, the third for 6 - 9.. I hope this makes sense ( I am open to alternate ways to go about this) anyways, heres my code. I dont really like this way, even though it works. I do want speed though beccause i am making a suduko solver. //a quadrant returns the mini 3 x 3 //row 1 has three quads,"1", "2", 3" //row 2 has three quads "1", "2", "3" etc public int[,] GetQuadrant(int rnum, int qnum) { int[,] returnMatrix = new int[3, 3]; int colBegin, colEnd, rowBegin, rowEnd, row, column; //this is so we can keep track of the new matrix row = 0; column = 0; switch (qnum) { case 1: colBegin = 0; colEnd = 3; break; case 2: colBegin = 3; colEnd = 6; break; case 3: colBegin = 6; colEnd = 9; break; default: colBegin = 0; colEnd = 0; break; } switch (rnum) { case 1: rowBegin = 0; rowEnd = 3; break; case 2: rowBegin = 3; rowEnd = 6; break; case 3: rowBegin = 6; rowEnd = 9; break; default: rowBegin = 0; rowEnd = 0; break; } for (int i = rowBegin ; i < rowEnd; i++) { for (int j = colBegin; j < colEnd; j++) { returnMatrix[row, column] = _matrix[i, j]; column++; } column = 0; row++; } return returnMatrix; }

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  • Where can I find BLAS example code (in Fortran)?

    - by Feynman
    I have been searching for decent documentation on blas, and I have found some 315 pages of dense material that ctrl-f does not work on. It provides all the information regarding what input arguments the routines take, but there are a LOT of input arguments and I could really use some example code. I am unable to locate any. I know there has to be some or no one would be able to use these libraries! Specifically, I use ATLAS installed via macports on a mac osx 10.5.8 and I use gfortran from gcc 4.4 (also installed via macports). I am coding in Fortran 90. I am still quite new to Fortran, but I have a fair amount of experience with mathematica, matlab, perl, and shell scripting. I would like to be able to initialize and multiply a dense complex vector by a dense symmetric (but not hermitian) complex matrix. The elements of the matrix are defined through a mathematical function of the indices--call it f(i,j). Could anyone provide some code or a link to some code?

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  • Have a trouble with the function roots

    - by user3707462
    Hey guys I have multiple problems with using function 'roots'. I Have to find zeros of 's^1000 + 1'. I made Y = zeros(1,1000) then manually changed the 1000th matrice to '1'. but then 'root' function does not work with it ! Another problem is that I am having trouble with matrix multiplication. The question is finding zeros(roots) of (s^6 + 6*s^5 + 15*s^4 + 20*s^3 + 15*s^2 + 6*s +1)*(s^6 + 6s^5 + 15*s^4 +15*s^2 +6*s +1) so i did: a = [1 6 15 20 15 6 1] b = [1 6 15 0 15 6 1] y = a.*b; roots(y) but this gives me -27.9355 + 0.0000i -8.2158 + 0.0000i 0.1544 + 0.9880i 0.1544 - 0.9880i -0.1217 + 0.0000i -0.0358 + 0.0000i where I calculate the original equation with wolfram then I have made matrix as : p = [1 12 66 200 375 492 524 492 375 200 66 12 1] roots(p) and this gives me : -3.1629 + 2.5046i -3.1629 - 2.5046i 0.3572 + 0.9340i 0.3572 - 0.9340i -1.0051 + 0.0000i -1.0025 + 0.0044i -1.0025 - 0.0044i -0.9975 + 0.0044i -0.9975 - 0.0044i -0.9949 + 0.0000i -0.1943 + 0.1539i -0.1943 - 0.1539i and I think the second solution is right (that is what wolfram alpha gave me) How would you answer these two questions through matlab guys?

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  • 2D Rendering with OpenGL ES 2.0 on Android (matrices not working)

    - by TranquilMarmot
    So I'm trying to render two moving quads, each at different locations. My shaders are as simple as possible (vertices are only transformed by the modelview-projection matrix, there's only one color). Whenever I try and render something, I only end up with slivers of color! I've only done work with 3D rendering in OpenGL before so I'm having issues with 2D stuff. Here's my basic rendering loop, simplified a bit (I'm using the Matrix manipulation methods provided by android.opengl.Matrix and program is a custom class I created that just calls GLES20.glUniformMatrix4fv()): Matrix.orthoM(projection, 0, 0, windowWidth, 0, windowHeight, -1, 1); program.setUniformMatrix4f("Projection", projection); At this point, I render the quads (this is repeated for each quad): Matrix.setIdentityM(modelview, 0); Matrix.translateM(modelview, 0, quadX, quadY, 0); program.setUniformMatrix4f("ModelView", modelview); quad.render(); // calls glDrawArrays and all I see is a sliver of the color each quad is! I'm at my wits end here, I've tried everything I can think of and I'm at the point where I'm screaming at my computer and tossing phones across the room. Anybody got any pointers? Am I using ortho wrong? I'm 100% sure I'm rendering everything at a Z value of 0. I tried using frustumM instead of orthoM, which made it so that I could see the quads but they would get totally skewed whenever they got moved, which makes sense if I correctly understand the way frustum works (it's more for 3D rendering, anyway). If it makes any difference, I defined my viewport with GLES20.glViewport(0, 0, windowWidth, windowHeight); Where windowWidth and windowHeight are the same values that are pased to orthoM It might be worth noting that the android.opengl.Matrix methods take in an offset as the second parameter so that multiple matrices can be shoved into one array, so that'w what the first 0 is for For reference, here's my vertex shader code: uniform mat4 ModelView; uniform mat4 Projection; attribute vec4 vPosition; void main() { mat4 mvp = Projection * ModelView; gl_Position = vPosition * mvp; } I tried swapping Projection * ModelView with ModelView * Projection but now I just get some really funky looking shapes... EDIT Okay, I finally figured it out! (Note: Since I'm new here (longtime lurker!) I can't answer my own question for a few hours, so as soon as I can I'll move this into an actual answer to the question) I changed Matrix.orthoM(projection, 0, 0, windowWidth, 0, windowHeight, -1, 1); to float ratio = windowWwidth / windowHeight; Matrix.orthoM(projection, 0, 0, ratio, 0, 1, -1, 1); I then had to scale my projection matrix to make it a lot smaller with Matrix.scaleM(projection, 0, 0.05f, 0.05f, 1.0f);. I then added an offset to the modelview translations to simulate a camera so that I could center on my action (so Matrix.translateM(modelview, 0, quadX, quadY, 0); was changed to Matrix.translateM(modelview, 0, quadX + camX, quadY + camY, 0);) Thanks for the help, all!

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