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  • Problem with boundary collision

    - by James Century
    The problem: When the player hits the left boundary he stops (this is exactly what I want), when he hits the right boundary. He continues until his rectangle's left boundary meets with the right boundary. Outcome: https://www.youtube.com/watch?v=yuJfIWZ_LL0&feature=youtu.be My Code public class Player extends GameObject{ BufferedImageLoader loader; Texture tex = Game.getInstance(); BufferedImage image; Animation playerWalkLeft; private HealthBarManager healthBar; private String username; private int width; private ManaBarManager manaBar; public Player(float x, float y, ObjectID ID) { super(x, y, ID, null); loader = new BufferedImageLoader(); playerWalkLeft = new Animation(5,tex.player[10],tex.player[11],tex.player[12],tex.player[13],tex.player[14],tex.player[15],tex.player[17],tex.player[18]); } public void tick(LinkedList<GameObject> object) { setX(getX()+velX); setY(getY()+velY); playerWalkLeft.runAnimation(); } public void render(Graphics g) { g.setColor(Color.BLACK); FontMetrics fm = g.getFontMetrics(g.getFont()); if(username != null) width = fm.stringWidth(username); if(username != null){ g.drawString(username,(int) x-width/2+15,(int) y); } if(velX != 0){ playerWalkLeft.drawAnimation(g, (int)x, (int)y); }else{ g.drawImage(tex.player[16], (int)x, (int)y, null); } g.setColor(Color.PINK); g.drawRect((int)x,(int)y,33,48); g.drawRect(0,0,(int)Game.getWalkableBounds().getWidth(), (int)Game.getWalkableBounds().getHeight()); } @SuppressWarnings("unused") private Image getCurrentImage() { return image; } public float getX() { return x; } public float getY() { return y; } public void setX(float x) { Rectangle gameBoundry = Game.getWalkableBounds(); if(x >= gameBoundry.getMinX() && x <= gameBoundry.getMaxX()){ this.x = x; } } public void setY(float y) { //IGNORE THE SetY please. this.y = y; } public float getVelX() { return velX; } public void setHealthBar(HealthBarManager healthBar){ this.healthBar = healthBar; } public HealthBarManager getHealthBar(){ return healthBar; } public float getVelY() { return velY; } public void setVelX(float velX) { this.velX = velX; } public void setVelY(float velY) { this.velY = velY; } public ObjectID getID() { return ID; } public void setUsername(String playerName) { this.username = playerName; } public String getUsername(){ return this.username; } public void setManaBar(ManaBarManager manaBar) { this.manaBar = manaBar; } public ManaBarManager getManaBar(){ return manaBar; } public int getLevel(){ return 1; } public boolean isPlayerInsideBoundry(float x, float y){ Rectangle boundry = Game.getWalkableBounds(); if(boundry.contains(x,y)){ return true; } return false; } } What I've tried: - Using a method that checks if the game boundary contains player boundary rectangle. This gave me the same result as what the check statement in my setX did.

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  • XNA 2D Board game - trouble with the cursor

    - by Adorjan
    I just have started making a simple 2D board game using XNA, but I got stuck at the movement of the cursor. This is my problem: I have a 10x10 table on with I should use a cursor to navigate. I simply made that table with the spriteBatch.Draw() function because I couldn't do it on another way. So here is what I did with the cursor: public override void LoadContent() { ... mutato.Position = new Vector2(X, Y); //X=103, Y=107; mutato.Sebesseg = 45; ... mutato.Initialize(content.Load<Texture2D>("cursor"),mutato.Position,mutato.Sebesseg); ... } public override void HandleInput(InputState input) { if (input == null) throw new ArgumentNullException("input"); // Look up inputs for the active player profile. int playerIndex = (int)ControllingPlayer.Value; KeyboardState keyboardState = input.CurrentKeyboardStates[playerIndex]; if (input.IsPauseGame(ControllingPlayer) || gamePadDisconnected) { ScreenManager.AddScreen(new PauseMenuScreen(), ControllingPlayer); } else { // Otherwise move the player position. if (keyboardState.IsKeyDown(Keys.Down)) { Y = (int)mutato.Position.Y + mutato.Move; } if (keyboardState.IsKeyDown(Keys.Up)) { Y = (int)mutato.Position.Y - mutato.Move; } if (keyboardState.IsKeyDown(Keys.Left)) { X = (int)mutato.Position.X - mutato.Move; } if (keyboardState.IsKeyDown(Keys.Right)) { X = (int)mutato.Position.X + mutato.Move; } } } public override void Draw(GameTime gameTime) { mutato.Draw(spriteBatch); } Here's the cursor's (mutato) class: using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Graphics; namespace Battleship.Components { class Cursor { public Texture2D Cursortexture; public Vector2 Position; public int Move; public void Initialize(Texture2D texture, Vector2 position,int move) { Cursortexture = texture; Position = position; Move = move; } public void Update() { } public void Draw(SpriteBatch spriteBatch) { spriteBatch.Draw(Cursortexture, Position, Color.White); } } } And here is a part of the InputState class where I think I should change something: public bool IsNewKeyPress(Keys key, PlayerIndex? controllingPlayer, out PlayerIndex playerIndex) { if (controllingPlayer.HasValue) { // Read input from the specified player. playerIndex = controllingPlayer.Value; int i = (int)playerIndex; return (CurrentKeyboardStates[i].IsKeyDown(key) && LastKeyboardStates[i].IsKeyUp(key)); } } If I leave the movement operation like this it doesn't have any sense: X = (int)mutato.Position.X - mutato.Move; However if I modify it to this: X = (int)mutato.Position.X--; it moves smoothly. Instead of this I need to move the cursor by fields (45 pixels), but I don't have any idea how to manage it.

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  • Setting an XAML Window always on top (but no TopMost property)

    - by Brian Scherady
    I am developing an application based on OptiTrack SDK (from NaturalPoint). I need to run the application window as "Always on Top". The window is designed in XAML and is controled in the class "CameraView" but it does not seem to include a "TopMost" property or equivalent. Attached are the code of "CameraView.xaml.cs" and the code of "CameraView.xaml" that are part of OptiTrack SDK (NaturalPoint) called "Single_Camera_CSharp_.NET_3.0". One could expect the class CameraView to contain properties or members to set the position of the window on the screen or to set it to TopMost but as far as searched I found nothing. I wonder what I should do. Thank you, Brian ================ "CameraView.xaml.cs" using System; using System.IO; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Navigation; using System.Drawing.Imaging; using System.Drawing.Drawing2D; using System.Windows.Threading; namespace TestProject { public partial class CameraView { private const int NP_OPTION_OBJECT_COLOR_OPTION = 3; private const int NP_OPTION_VIDEO_TYPE = 48; private const int NP_OPTION_NUMERIC_DISPLAY_ON = 71; private const int NP_OPTION_NUMERIC_DISPLAY_OFF = 72; private const int NP_OPTION_FETCH_RLE = 73; private const int NP_OPTION_FETCH_GRAYSCALE = 74; private const int NP_OPTION_FRAME_DECIMATION = 52; private const int NP_OPTION_INTENSITY = 50; private const int NP_OPTION_SEND_EMPTY_FRAMES = 41; private const int NP_OPTION_THRESHOLD = 5; private const int NP_OPTION_EXPOSURE = 46; private const int NP_OPTION_SEND_FRAME_MASK = 73; private const int NP_OPTION_TEXT_OVERLAY_OPTION = 74; // public delegate void OnCameraViewCreate(CameraView camera); // public static OnCameraViewCreate onCameraViewCreate; private System.Drawing.Bitmap raw = new System.Drawing.Bitmap(353, 288, System.Drawing.Imaging.PixelFormat.Format32bppArgb); private int mFrameCounter; private int mDisplayCounter; private DispatcherTimer timer1 = new DispatcherTimer(); private bool mVideoFrameAvailable = false; private int mNumeric = -1; private bool mGreyscale = false; private bool mOverlay = true; public CameraView() { this.InitializeComponent(); timer1.Interval = new TimeSpan(0, 0, 0, 0, 10); timer1.Tick += new EventHandler(timer1_Tick); } public int Numeric { get { return mNumeric; } set { mNumeric = value % 100; if (mNumeric = 0) { if (Camera != null) Camera.SetOption(NP_OPTION_NUMERIC_DISPLAY_ON, value % 100); } } } private bool CameraRunning = false; private OptiTrack.NPCamera mCamera; public OptiTrack.NPCamera Camera { get { return mCamera; } set { if (mCamera == value) return; //== Don't do anything if you're assigning the same camera == if (mCamera != null) { //== Shut the selected camera down ==<< if (CameraRunning) { CameraRunning = false; mCamera.Stop(); mCamera.FrameAvailable -= FrameAvailable; } } mCamera = value; if (mCamera == null) { mNumeric = -1; } else { serialLabel.Content = "Camera "+mCamera.SerialNumber.ToString(); //mNumeric.ToString(); } } } private void FrameAvailable(OptiTrack.NPCamera Camera) { mFrameCounter++; try { OptiTrack.NPCameraFrame frame = Camera.GetFrame(0); int id = frame.Id; if (CameraRunning) { GetFrameData(Camera, frame); } frame.Free(); } catch (Exception) { int r = 0; r++; } } private void GetFrameData(OptiTrack.NPCamera camera, OptiTrack.NPCameraFrame frame) { BitmapData bmData = raw.LockBits(new System.Drawing.Rectangle(0, 0, raw.Width, raw.Height), ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppArgb); int stride = bmData.Stride; System.IntPtr bufferPtr = bmData.Scan0; unsafe { byte* buffer = (byte*)(void*)bufferPtr; camera.GetFrameImage(frame, bmData.Width, bmData.Height, bmData.Stride, 32, ref buffer[0]); } raw.UnlockBits(bmData); mVideoFrameAvailable = true; } private void timer1_Tick(object sender, EventArgs e) { if (CameraRunning && mVideoFrameAvailable) { mVideoFrameAvailable = false; cameraImage.Source = Img(raw); mDisplayCounter++; } } private System.Windows.Media.ImageSource Img(System.Drawing.Bitmap img) { System.Drawing.Imaging.BitmapData bmData = img.LockBits(new System.Drawing.Rectangle(0, 0, img.Width, img.Height), System.Drawing.Imaging.ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppPArgb); System.Windows.Media.Imaging.BitmapSource bitmap = System.Windows.Media.Imaging.BitmapSource.Create( img.Width, img.Height, 96, 96, PixelFormats.Bgra32, System.Windows.Media.Imaging.BitmapPalettes.WebPalette, bmData.Scan0, bmData.Stride * bmData.Height, bmData.Stride); img.UnlockBits(bmData); return bitmap; } private void startStopButton_Click(object sender, RoutedEventArgs e) { if (CameraRunning) StopCamera(); else StartCamera(); } public void StartCamera() { if (Camera != null) { mFrameCounter = 0; mDisplayCounter = 0; Camera.FrameAvailable += FrameAvailable; Camera.SetOption(NP_OPTION_VIDEO_TYPE, 0); Camera.SetOption(NP_OPTION_FRAME_DECIMATION, 1); Camera.SetOption(NP_OPTION_INTENSITY, 0); Camera.SetOption(NP_OPTION_EXPOSURE, 10); Camera.SetOption(NP_OPTION_THRESHOLD, 50); Camera.SetOption(NP_OPTION_OBJECT_COLOR_OPTION, 0); SetOverlayOption(); SetGreyscaleOption(); timer1.Start(); Camera.Start(); CameraRunning = true; this.Numeric = mNumeric; startStopButton.Content = "Stop Camera"; } } private void SetGreyscaleOption() { if(mGreyscale) Camera.SetOption(NP_OPTION_VIDEO_TYPE, 1); else Camera.SetOption(NP_OPTION_VIDEO_TYPE, 0); } private void SetOverlayOption() { if(mOverlay) Camera.SetOption(NP_OPTION_TEXT_OVERLAY_OPTION, 255); else Camera.SetOption(NP_OPTION_TEXT_OVERLAY_OPTION, 0); } public void StopCamera() { if (Camera != null) { Camera.Stop(); timer1.Stop(); CameraRunning = false; Camera.FrameAvailable -= FrameAvailable; Camera.SetOption(NP_OPTION_NUMERIC_DISPLAY_OFF, 0); startStopButton.Content = "Start Camera"; } } private void greyscaleButton_Click(object sender, RoutedEventArgs e) { if(mGreyscale) mGreyscale = false; else mGreyscale = true; SetGreyscaleOption(); } private void OverlayButton_Click(object sender, RoutedEventArgs e) { if(mOverlay) mOverlay = false; else mOverlay = true; SetOverlayOption(); } private void exposureSlider_ValueChanged(object sender, RoutedEventArgs e) { if (mCamera!=null) { mCamera.SetOption(NP_OPTION_EXPOSURE, (int) this.exposureSlider.Value); } } private void thresholdSlider_ValueChanged(object sender, RoutedEventArgs e) { if (mCamera != null) { mCamera.SetOption(NP_OPTION_THRESHOLD, (int)this.thresholdSlider.Value); } } private void optionsButton_Click(object sender, RoutedEventArgs e) { if (!propertyPanel.IsVisible) propertyPanel.Visibility = Visibility.Visible; else propertyPanel.Visibility = Visibility.Collapsed; } } } ================ "CameraView.xaml"

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  • How to make a player stay within bounds of world with 2D Camera

    - by Craig
    Im creating a simple top down survival game. At the moment, i have the sprite which is a ship and moves by rotating left or right then going forward in that direction. I have implemented a 2D camera, its always centered on the player. However, when i move towards the bounds of the world that the sprite is in it just keeps on going :( How to i sort it that it stops at the edge of the world and cant go beyond it? Cheers :) Below is the main game class 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 GamesCoursework_1 { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; // player variables Texture2D Ship; Vector2 Ship_Position; float Ship_Rotation = 0.0f; Vector2 Ship_Origin; Vector2 Ship_Velocity; const float tangentialVelocity = 4f; float friction = 0.05f; static Point CameraViewport = new Point(800, 800); Camera2d cam = new Camera2d((int)CameraViewport.X, (int)CameraViewport.Y); //Size of world static Point worldSize = new Point(1600, 1600); // Screen variables static Point worldCenter = new Point(worldSize.X / 2, worldSize.Y / 2); Rectangle playerBounds = new Rectangle(CameraViewport.X / 2, CameraViewport.Y / 2, worldSize.X - CameraViewport.X, worldSize.Y - CameraViewport.Y); Rectangle worldBounds = new Rectangle(0, 0, worldSize.X, worldSize.Y); Texture2D background; public Game1() { graphics = new GraphicsDeviceManager(this); graphics.PreferredBackBufferWidth = CameraViewport.X; graphics.PreferredBackBufferHeight = CameraViewport.Y; 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); // TODO: use this.Content to load your game content here Ship = Content.Load<Texture2D>("Ship"); Ship_Origin.X = Ship.Width / 2; Ship_Origin.Y = Ship.Height / 2; background = Content.Load<Texture2D>("aus"); Ship_Position = new Vector2(worldCenter.X, worldCenter.Y); cam.Pos = Ship_Position; cam.Zoom = 1f; } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { // TODO: Unload any non ContentManager content here } /// <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) { // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); // TODO: Add your update logic here Ship_Position = Ship_Velocity + Ship_Position; keyPressed(); base.Update(gameTime); } /// <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); // TODO: Add your drawing code here spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend, null, null, null,null, cam.get_transformation(GraphicsDevice)); spriteBatch.Draw(background, Vector2.Zero, Color.White); spriteBatch.Draw(Ship, Ship_Position, Ship.Bounds, Color.White, Ship_Rotation, Ship_Origin, 1.0f, SpriteEffects.None, 0f); spriteBatch.End(); base.Draw(gameTime); } private void Ship_Move(Vector2 move) { Ship_Position += move; } private void keyPressed() { KeyboardState keyState; // Move right keyState = Keyboard.GetState(); if (keyState.IsKeyDown(Keys.Right)) { Ship_Rotation = Ship_Rotation + 0.1f; } if (keyState.IsKeyDown(Keys.Left)) { Ship_Rotation = Ship_Rotation - 0.1f; } if (keyState.IsKeyDown(Keys.Up)) { Ship_Velocity.X = (float)Math.Cos(Ship_Rotation) * tangentialVelocity; Ship_Velocity.Y = (float)Math.Sin(Ship_Rotation) * tangentialVelocity; if ((int)Ship_Position.Y < playerBounds.Bottom && (int)Ship_Position.Y > playerBounds.Top) cam._pos.Y = Ship_Position.Y; if ((int)Ship_Position.X > playerBounds.Left && (int)Ship_Position.X < playerBounds.Right) cam._pos.X = Ship_Position.X; //tried world bounds here if (!worldBounds.Contains(new Point((int)Ship_Position.X, (int)Ship_Position.Y))) Ship_Position -= new Vector2(0.0f, -tangentialVelocity * 2); if (!worldBounds.Contains(new Point((int)Ship_Position.X, (int)Ship_Position.Y))) Ship_Position -= new Vector2(0.0f, 2 * tangentialVelocity); } else if(Ship_Velocity != Vector2.Zero) { float i = Ship_Velocity.X; float j = Ship_Velocity.Y; Ship_Velocity.X = i -= friction * i; Ship_Velocity.Y = j -= friction * j; if ((int)Ship_Position.Y < playerBounds.Bottom && (int)Ship_Position.Y > playerBounds.Top) cam._pos.Y = Ship_Position.Y; if ((int)Ship_Position.X > playerBounds.Left && (int)Ship_Position.X < playerBounds.Right) cam._pos.X = Ship_Position.X; } if (keyState.IsKeyDown(Keys.Q)) { if (cam.Zoom < 2f) cam.Zoom += 0.05f; } if (keyState.IsKeyDown(Keys.A)) { if (cam.Zoom > 0.3f) cam.Zoom -= 0.05f; } } } } my 2d camera class using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Graphics; namespace GamesCoursework_1 { public class Camera2d { protected float _zoom; // Camera Zoom public Matrix _transform; // Matrix Transform public Vector2 _pos; // Camera Position protected float _rotation; // Camera Rotation public int _viewportWidth, _viewportHeight; // viewport size public Camera2d(int ViewportWidth, int ViewportHeight) { _zoom = 1.0f; _rotation = 0.0f; _pos = Vector2.Zero; _viewportWidth = ViewportWidth; _viewportHeight = ViewportHeight; } // Sets and gets zoom public float Zoom { get { return _zoom; } set { _zoom = value; if (_zoom < 0.1f) _zoom = 0.1f; } // Negative zoom will flip image } public float Rotation { get { return _rotation; } set { _rotation = value; } } // Auxiliary function to move the camera public void Move(Vector2 amount) { _pos += amount; } // Get set position public Vector2 Pos { get { return _pos; } set { _pos = value; } } public Matrix get_transformation(GraphicsDevice graphicsDevice) { _transform = // Thanks to o KB o for this solution Matrix.CreateTranslation(new Vector3(-_pos.X, -_pos.Y, 0)) * Matrix.CreateRotationZ(Rotation) * Matrix.CreateScale(new Vector3(Zoom, Zoom, 1)) * Matrix.CreateTranslation(new Vector3(_viewportWidth * 0.5f, _viewportHeight * 0.5f, 0)); return _transform; } } }

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  • BlackBerry - TouchEvent on multiple managers

    - by rupesh
    Hi all i am new to blackberry application development here is my question i am using two verticalfieldmanager "layout" and "manager" in my application. layout has three custom button field and layout is inside manager. i am not able to implement touch event , here is my code: public class MenuScreen extends MainScreen { public MenuScreen() { super(Screen.DEFAULT_CLOSE); Bitmap menuBackgroundImage = Bitmap .getBitmapResource("com/greetings/Images/MenuBackground.jpg"); final VerticalFieldManager layout = new VerticalFieldManager() { public boolean touchEvent(TouchEvent message) { int x = message.getGlobalX(1); int y = message.getGlobalY(1); if (getExtent().contains(x, y)) { int fieldI = getFieldAtLocation(x, y); Field field = getField(fieldI); field.setFocus(); return super.touchEvent(message); } return false; } }; ButtonField categories = new ButtonField("Categories") { public void run() { Dialog.alert("one"); } public boolean touchEvent(TouchEvent message) { int x = message.getX(1); int y = message.getY(1); int w = getWidth(); int h = getHeight(); if (x >= 0 && x <= w && y >= 0 && y <= h) { switch (message.getEvent()) { case TouchEvent.DOWN: setFocus(); return true; case TouchEvent.UNCLICK: run(); return true; } } return false; } }; ButtonField help = new ButtonField("Help") { public void run() { Dialog.alert("help"); } public boolean touchEvent(TouchEvent message) { int x = message.getX(1); int y = message.getY(1); int w = getWidth(); int h = getHeight(); if (x >= 0 && x <= w && y >= 0 && y <= h) { switch (message.getEvent()) { case TouchEvent.DOWN: setFocus(); return true; case TouchEvent.UNCLICK: run(); return true; } } return false; } }; ButtonField developer = new ButtonField("Developer") { public void run() { Dialog.alert("Developer"); } public boolean touchEvent(TouchEvent message) { int x = message.getX(1); int y = message.getY(1); int w = getWidth(); int h = getHeight(); if (x >= 0 && x <= w && y >= 0 && y <= h) { switch (message.getEvent()) { case TouchEvent.DOWN: setFocus(); return true; case TouchEvent.UNCLICK: run(); return true; } } return false; } }; layout.add(categories); layout.add(help); layout.add(developer); VerticalFieldManager manager = new VerticalFieldManager() { protected void sublayout(int width, int height) { width = Display.getWidth(); height = Display.getHeight(); super.sublayout(width, height); setPositionChild(layout, width - 245, height - 350); setExtent(width, height); } }; manager.setBackground(BackgroundFactory .createBitmapBackground(menuBackgroundImage)); manager.add(layout); add(manager); } }

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  • Python: Improving long cumulative sum

    - by Bo102010
    I have a program that operates on a large set of experimental data. The data is stored as a list of objects that are instances of a class with the following attributes: time_point - the time of the sample cluster - the name of the cluster of nodes from which the sample was taken code - the name of the node from which the sample was taken qty1 = the value of the sample for the first quantity qty2 = the value of the sample for the second quantity I need to derive some values from the data set, grouped in three ways - once for the sample as a whole, once for each cluster of nodes, and once for each node. The values I need to derive depend on the (time sorted) cumulative sums of qty1 and qty2: the maximum value of the element-wise sum of the cumulative sums of qty1 and qty2, the time point at which that maximum value occurred, and the values of qty1 and qty2 at that time point. I came up with the following solution: dataset.sort(key=operator.attrgetter('time_point')) # For the whole set sys_qty1 = 0 sys_qty2 = 0 sys_combo = 0 sys_max = 0 # For the cluster grouping cluster_qty1 = defaultdict(int) cluster_qty2 = defaultdict(int) cluster_combo = defaultdict(int) cluster_max = defaultdict(int) cluster_peak = defaultdict(int) # For the node grouping node_qty1 = defaultdict(int) node_qty2 = defaultdict(int) node_combo = defaultdict(int) node_max = defaultdict(int) node_peak = defaultdict(int) for t in dataset: # For the whole system ###################################################### sys_qty1 += t.qty1 sys_qty2 += t.qty2 sys_combo = sys_qty1 + sys_qty2 if sys_combo > sys_max: sys_max = sys_combo # The Peak class is to record the time point and the cumulative quantities system_peak = Peak(time_point=t.time_point, qty1=sys_qty1, qty2=sys_qty2) # For the cluster grouping ################################################## cluster_qty1[t.cluster] += t.qty1 cluster_qty2[t.cluster] += t.qty2 cluster_combo[t.cluster] = cluster_qty1[t.cluster] + cluster_qty2[t.cluster] if cluster_combo[t.cluster] > cluster_max[t.cluster]: cluster_max[t.cluster] = cluster_combo[t.cluster] cluster_peak[t.cluster] = Peak(time_point=t.time_point, qty1=cluster_qty1[t.cluster], qty2=cluster_qty2[t.cluster]) # For the node grouping ##################################################### node_qty1[t.node] += t.qty1 node_qty2[t.node] += t.qty2 node_combo[t.node] = node_qty1[t.node] + node_qty2[t.node] if node_combo[t.node] > node_max[t.node]: node_max[t.node] = node_combo[t.node] node_peak[t.node] = Peak(time_point=t.time_point, qty1=node_qty1[t.node], qty2=node_qty2[t.node]) This produces the correct output, but I'm wondering if it can be made more readable/Pythonic, and/or faster/more scalable. The above is attractive in that it only loops through the (large) dataset once, but unattractive in that I've essentially copied/pasted three copies of the same algorithm. To avoid the copy/paste issues of the above, I tried this also: def find_peaks(level, dataset): def grouping(object, attr_name): if attr_name == 'system': return attr_name else: return object.__dict__[attrname] cuml_qty1 = defaultdict(int) cuml_qty2 = defaultdict(int) cuml_combo = defaultdict(int) level_max = defaultdict(int) level_peak = defaultdict(int) for t in dataset: cuml_qty1[grouping(t, level)] += t.qty1 cuml_qty2[grouping(t, level)] += t.qty2 cuml_combo[grouping(t, level)] = (cuml_qty1[grouping(t, level)] + cuml_qty2[grouping(t, level)]) if cuml_combo[grouping(t, level)] > level_max[grouping(t, level)]: level_max[grouping(t, level)] = cuml_combo[grouping(t, level)] level_peak[grouping(t, level)] = Peak(time_point=t.time_point, qty1=node_qty1[grouping(t, level)], qty2=node_qty2[grouping(t, level)]) return level_peak system_peak = find_peaks('system', dataset) cluster_peak = find_peaks('cluster', dataset) node_peak = find_peaks('node', dataset) For the (non-grouped) system-level calculations, I also came up with this, which is pretty: dataset.sort(key=operator.attrgetter('time_point')) def cuml_sum(seq): rseq = [] t = 0 for i in seq: t += i rseq.append(t) return rseq time_get = operator.attrgetter('time_point') q1_get = operator.attrgetter('qty1') q2_get = operator.attrgetter('qty2') timeline = [time_get(t) for t in dataset] cuml_qty1 = cuml_sum([q1_get(t) for t in dataset]) cuml_qty2 = cuml_sum([q2_get(t) for t in dataset]) cuml_combo = [q1 + q2 for q1, q2 in zip(cuml_qty1, cuml_qty2)] combo_max = max(cuml_combo) time_max = timeline.index(combo_max) q1_at_max = cuml_qty1.index(time_max) q2_at_max = cuml_qty2.index(time_max) However, despite this version's cool use of list comprehensions and zip(), it loops through the dataset three times just for the system-level calculations, and I can't think of a good way to do the cluster-level and node-level calaculations without doing something slow like: timeline = defaultdict(int) cuml_qty1 = defaultdict(int) #...etc. for c in cluster_list: timeline[c] = [time_get(t) for t in dataset if t.cluster == c] cuml_qty1[c] = [q1_get(t) for t in dataset if t.cluster == c] #...etc. Does anyone here at Stack Overflow have suggestions for improvements? The first snippet above runs well for my initial dataset (on the order of a million records), but later datasets will have more records and clusters/nodes, so scalability is a concern. This is my first non-trivial use of Python, and I want to make sure I'm taking proper advantage of the language (this is replacing a very convoluted set of SQL queries, and earlier versions of the Python version were essentially very ineffecient straight transalations of what that did). I don't normally do much programming, so I may be missing something elementary. Many thanks!

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  • Generics and Performance question.

    - by Tarmon
    Hey Everyone, I was wondering if anyone could look over a class I wrote, I am receiving generic warnings in Eclipse and I am just wondering if it could be cleaned up at all. All of the warnings I received are surrounded in ** in my code below. The class takes a list of strings in the form of (hh:mm AM/PM) and converts them into HourMinute objects in order to find the first time in the list that comes after the current time. I am also curious about if there are more efficient ways to do this. This works fine but the student in me just wants to find out how I could do this better. public class FindTime { private String[] hourMinuteStringArray; public FindTime(String[] hourMinuteStringArray){ this.hourMinuteStringArray = hourMinuteStringArray; } public int findTime(){ HourMinuteList hourMinuteList = convertHMStringArrayToHMArray(hourMinuteStringArray); Calendar calendar = new GregorianCalendar(); int hour = calendar.get(Calendar.HOUR_OF_DAY); int minute = calendar.get(Calendar.MINUTE); HourMinute now = new HourMinute(hour,minute); int nearestTimeIndex = findNearestTimeIndex(hourMinuteList, now); return nearestTimeIndex; } private int findNearestTimeIndex(HourMinuteList hourMinuteList, HourMinute now){ HourMinute current; int position = 0; Iterator<HourMinute> iterator = **hourMinuteList.iterator()**; while(iterator.hasNext()){ current = (HourMinute) iterator.next(); if(now.compareTo(current) == -1){ return position; } position++; } return position; } private static HourMinuteList convertHMStringArrayToHMArray(String[] times){ FindTime s = new FindTime(new String[1]); HourMinuteList list = s.new HourMinuteList(); String[] splitTime = new String[3]; for(String time : times ){ String[] tempFirst = time.split(":"); String[] tempSecond = tempFirst[1].split(" "); splitTime[0] = tempFirst[0]; splitTime[1] = tempSecond[0]; splitTime[2] = tempSecond[1]; int hour = Integer.parseInt(splitTime[0]); int minute = Integer.parseInt(splitTime[1]); HourMinute hm; if(splitTime[2] == "AM"){ hm = s.new HourMinute(hour,minute); } else if((splitTime[2].equals("PM")) && (hour < 12)){ hm = s.new HourMinute(hour + 12,minute); } else{ hm = s.new HourMinute(hour,minute); } **list.add(hm);** } return list; } class **HourMinuteList** extends **ArrayList** implements RandomAccess{ } class HourMinute implements **Comparable** { int hour; int minute; public HourMinute(int hour, int minute) { setHour(hour); setMinute(minute); } int getMinute() { return this.minute; } String getMinuteString(){ if(this.minute < 10){ return "0" + this.minute; }else{ return "" + this.minute; } } int getHour() { return this.hour; } void setHour(int hour) { this.hour = hour; } void setMinute(int minute) { this.minute = minute; } @Override public int compareTo(Object aThat) { if (aThat instanceof HourMinute) { HourMinute that = (HourMinute) aThat; if (this.getHour() == that.getHour()) { if (this.getMinute() > that.getMinute()) { return 1; } else if (this.getMinute() < that.getMinute()) { return -1; } else { return 0; } } else if (this.getHour() > that.getHour()) { return 1; } else if (this.getHour() < that.getHour()) { return -1; } else { return 0; } } return 0; } } If you have any questions let me know. Thanks, Rob

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  • get eigenvalue pca with java

    - by Muhamad Burhanudin
    I try use PCA to reduce dimention, and i use jama for help me using matrix. but, i got problem when get eigenvalue with jama. for example i hava 2 image dimention 100x100, then i create single matrix 2 image x (100x100). there is 20.000 pixel. and how to get reduction with eigenvalue? this is sample my code : public static void main(String[] args) { BufferedImage bi; int[] rgb; int R, G, B; // int[] jum; double[][] gray = new double[500][500] ; String[] baris = new String[1000]; try { //bi = ImageIO.read(new File("D:\\c.jpg")); int[][] pixelData = new int[bi.getHeight() * bi.getWidth()][3]; int counter = 0; for (int i = 0; i < bi.getHeight(); i++) { for (int j = 0; j < bi.getWidth(); j++) { gray[i][j] = getPixelData(bi, i, j); // R = getR(bi, i, j); //G = getG(bi, i, j); //B = getB(bi, i, j); //jum = R + G + B; // gray[counter] = Double.toString(R + G + B / 3); // System.out.println("Gray " +gray); //for (int k = 0; k < rgb.length; k++) { // pixelData[counter][k] = rgb[k]; // } counter++; } } } catch (IOException e) { e.printStackTrace(); } Matrix matrix = new Matrix(gray); PCA pca = new PCA(matrix); pca.getEigenvalue(6); String n = pca.toString(); System.err.println("nilai n "+n); //double dete = pcadete(matrix,3600); } private static int getPixelData(BufferedImage bi, int x, int y) { int argb = bi.getRGB(y, x); int r, g, b; int gray; int rgb[] = new int[]{ (argb >> 16) & 0xff, //red (argb >> 8) & 0xff, //green (argb) & 0xff //blue }; r = rgb[0]; g = rgb[1]; b = rgb[2]; gray = (r + g + b) / 3; System.out.println("gray: " + gray); return gray; } when i show eigenvalue in this code : PCA pca = new PCA(matrix); pca.getEigenvalue(6); String n = pca.toString(); System.err.println("nilai n "+n); Result is : nilai n PCA@c3e9e9 Can, u tell me what way to get eigenvalue and reduction dimension.

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  • Snake game, can't add new rectangles?

    - by user1814358
    I had seen some problem on other forum, and i tried to solve them but unsuccesfully, now is too intersting for me and i just need to solve this for my ego... lol Main problem is when snake eat first food, snake added one rectangle, when snake eat second food nothings changed? When snake head position and food position are same, then i try to add another rectangle, i have list where i stored rectangles coordinates x and y. What do you think, how i can to solve this problem? I think that i'm so close, but my brain has stopped. :( code: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace Zmijice { enum Kontrole { Desno,Levo,Gore,Dole,Stoj } public partial class Zmijice : Form { int koox; int kooy; private int x; private int y; private int c; private int b; private const int visina=20; //width private const int sirina=20; //height //private int m = 20; //private int n = 20; private List<int> SegmentX = new List<int>(); private List<int> SegmentY = new List<int>(); Random rnd = new Random(); private Kontrole Pozicija; public Zmijice() { InitializeComponent(); //slucajne pozicije pri startu x = rnd.Next(1, 20) * 20; y = rnd.Next(1, 20) * 20; c = rnd.Next(1, 20) * 20; b = rnd.Next(1, 20) * 20; Pozicija = Kontrole.Stoj; //stop on start } private void Tajmer_Tick(object sender, EventArgs e) { if (Pozicija == Kontrole.Stoj) { //none } if (Pozicija == Kontrole.Desno) { x += 20; } else if (Pozicija == Kontrole.Levo) { x -= 20; } else if (Pozicija == Kontrole.Gore) { y -= 20; } else if (Pozicija == Kontrole.Dole) { y += 20; } Invalidate(); } private void Zmijice_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Down) { Pozicija = Kontrole.Dole; } else if (e.KeyCode == Keys.Up) { Pozicija = Kontrole.Gore; } else if (e.KeyCode == Keys.Right) { Pozicija = Kontrole.Desno; } else if (e.KeyCode == Keys.Left) { Pozicija = Kontrole.Levo; } } private void Zmijice_Paint(object sender, PaintEventArgs e) { int counter = 1; //ako je pojela hranu if (x==c && y==b) { counter++; c = rnd.Next(1, 20); //nova pozicija hrrane c = c * 20; b = rnd.Next(1, 20); b = b * 20; //povecaj zmijicu SegmentX.Add(x); SegmentY.Add(y); //label1.Text = SegmentX.Count().ToString() + " " + SegmentY.Count().ToString(); //left if (Pozicija == Kontrole.Levo) { koox = x+20; kooy = y; } //right if (Pozicija == Kontrole.Desno) { koox = x-20; kooy = y; } //up if (Pozicija == Kontrole.Gore) { koox = x; kooy = y+20; } //down if (Pozicija == Kontrole.Dole) { koox = x; kooy = y-20; } } foreach (int k in SegmentX) { foreach (int l in SegmentY) { e.Graphics.FillRectangle(Brushes.Orange, koox, kooy, sirina, visina); } } koox = x; kooy = y; e.Graphics.FillRectangle(Brushes.DarkRed, x, y, sirina, visina); e.Graphics.FillRectangle(Brushes.Aqua, c, b, sirina, visina); } } }

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  • Roguelike FOV problem

    - by Manderin87
    I am working on a college compsci project and I would like some help with a field of view algorithm. I works mostly, but in some situations the algorithm sees through walls and hilights walls the player should not be able to see. void cMap::los(int x0, int y0, int radius) { //Does line of sight from any particular tile for(int x = 0; x < m_Height; x++) { for(int y = 0; y < m_Width; y++) { getTile(x,y)->setVisible(false); } } double xdif = 0; double ydif = 0; bool visible = false; float dist = 0; for (int x = MAX(x0 - radius,0); x < MIN(x0 + radius, m_Height); x++) { //Loops through x values within view radius for (int y = MAX(y0 - radius,0); y < MIN(y0 + radius, m_Width); y++) { //Loops through y values within view radius xdif = pow( (double) x - x0, 2); ydif = pow( (double) y - y0, 2); dist = (float) sqrt(xdif + ydif); //Gets the distance between the two points if (dist <= radius) { //If the tile is within view distance, visible = line(x0, y0, x, y); //check if it can be seen. if (visible) { //If it can be seen, getTile(x,y)->setVisible(true); //Mark that tile as viewable } } } } } bool cMap::line(int x0,int y0,int x1,int y1) { bool steep = abs(y1-y0) > abs(x1-x0); if (steep) { swap(x0, y0); swap(x1, y1); } if (x0 > x1) { swap(x0,x1); swap(y0,y1); } int deltax = x1-x0; int deltay = abs(y1-y0); int error = deltax/2; int ystep; int y = y0; if (y0 < y1) ystep = 1; else ystep = -1; for (int x = x0; x < x1; x++) { if ( steep && getTile(y,x)->isBlocked()) { getTile(y,x)->setVisible(true); getTile(y,x)->setDiscovered(true); return false; } else if (!steep && getTile(x,y)->isBlocked()) { getTile(x,y)->setVisible(true); getTile(x,y)->setDiscovered(true); return false; } error -= deltay; if (error < 0) { y = y + ystep; error = error + deltax; } } return true; } If anyone could help me make the first blocked tiles visible but stops the rest, I would appreciate it. thanks, Manderin87

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  • Need a hand understanding this Java code please :-)

    - by Brian
    Hi all, Just wondering if anyone would be able to take a look at this code for implementing the quicksort algorithm and answer me a few questions, please :-) public class Run { /*************************************************************************** * Quicksort code from Sedgewick 7.1, 7.2. **************************************************************************/ public static void quicksort(double[] a) { //shuffle(a); // to guard against worst-case quicksort(a, 0, a.length - 1, 0); } static void quicksort(final double[] a, final int left, final int right, final int tdepth) { if (right <= left) return; final int i = partition(a, left, right); if ((tdepth < 4) && ((i - left) > 1000)) { final Thread t = new Thread() { public void run() { quicksort(a, left, i - 1, tdepth + 1); } }; t.start(); quicksort(a, i + 1, right, tdepth + 1); try { t.join(); } catch (InterruptedException e) { throw new RuntimeException("Cancelled", e); } } else { quicksort(a, left, i - 1, tdepth); quicksort(a, i + 1, right, tdepth); } } // partition a[left] to a[right], assumes left < right private static int partition(double[] a, int left, int right) { int i = left - 1; int j = right; while (true) { while (less(a[++i], a[right])) // find item on left to swap ; // a[right] acts as sentinel while (less(a[right], a[--j])) // find item on right to swap if (j == left) break; // don't go out-of-bounds if (i >= j) break; // check if pointers cross exch(a, i, j); // swap two elements into place } exch(a, i, right); // swap with partition element return i; } // is x < y ? private static boolean less(double x, double y) { return (x < y); } // exchange a[i] and a[j] private static void exch(double[] a, int i, int j) { double swap = a[i]; a[i] = a[j]; a[j] = swap; } // shuffle the array a[] private static void shuffle(double[] a) { int N = a.length; for (int i = 0; i < N; i++) { int r = i + (int) (Math.random() * (N - i)); // between i and N-1 exch(a, i, r); } } // test client public static void main(String[] args) { int N = 5000000; // Integer.parseInt(args[0]); // generate N random real numbers between 0 and 1 long start = System.currentTimeMillis(); double[] a = new double[N]; for (int i = 0; i < N; i++) a[i] = Math.random(); long stop = System.currentTimeMillis(); double elapsed = (stop - start) / 1000.0; System.out.println("Generating input: " + elapsed + " seconds"); // sort them start = System.currentTimeMillis(); quicksort(a); stop = System.currentTimeMillis(); elapsed = (stop - start) / 1000.0; System.out.println("Quicksort: " + elapsed + " seconds"); } } My questions are: What is the purpose of the variable tdepth? Is this considered a "proper" implementation of a parallel quicksort? I ask becuase it doesn't use implements Runnable or extends Thread... If it doesn't already, is it possible to modify this code to use multiple threads? By passing in the number of threads you want to use as a parameter, for example...? Many thanks, Brian

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  • where is the error in this C code , and how to get rid of the warnings?

    - by mekasperasky
    #include<stdio.h> #include<string.h> //This program is a sorting application that reads a sequence of numbers from a file and prints them on the screen . The reading from the file here , is a call back function . typedef int (*CompFunc)(const char* , const char* ); typedef int (*ReadCheck)(char nullcheck); char array[100]; //Let this fucntion be done in the library itself . It doesnt care as to where the compare function and how is it implemented . Meaning suppose the function wants to do sort in ascending order or in descending order then the changes have to be done by the client code in the "COMPARE" function who will be implementing the lib code . void ReadFile(FILE *fp,ReadCheck rc) { char a; char d[100]; int count = 0,count1=0; a=fgetc(fp); while(1 != (*rc)(a)) { if(a=='\0') { strcpy(array[count],d); count=count+1; } else { d[count1]=a; count1=count1+1; } } } void Bubblesort(int* array , int size , int elem_size , CompFunc cf) { int i,j; int *temp; for( i=0;i < size ;i++) { for ( j=0;j < size -1 ; j++) { // make the callback to the comparision function if(1 == (*cf)(array+j*elem_size,array+ (j+1)*elem_size)) { //interchanging of elements temp = malloc(sizeof(int *) * elem_size); memcpy(temp , array+j*elem_size,elem_size); memcpy(array+j*elem_size,array+(j+1)*elem_size,elem_size); memcpy(array + (j+1)*elem_size , temp , elem_size); free(temp); } } } } //Let these functions be done at the client side int Compare(const char* el1 , const char* el2) { int element1 = *(int*)el1; int element2 = *(int*)el2; if(element1 < element2 ) return -1; if(element1 > element2) return 1 ; return 0; } int ReadChecked(char nullcheck) { if (nullcheck=='\n') return 1; else return 0; } int main() { FILE fp1; int k; fp1=fopen("readdata.txt","r"); Readfile(fp1,&ReadChecked); Bubblesort((char*)array,5,sizeof(array[0]),&Compare); printf("after sorting \n"); for (k=0;k<5;k++) printf("%d",array[k]); return 0; } The error i get is fsc1.c: In function ‘ReadFile’: fsc1.c:19: warning: passing argument 1 of ‘strcpy’ makes pointer from integer without a cast fsc1.c: In function ‘Bubblesort’: fsc1.c:40: warning: passing argument 1 of ‘cf’ from incompatible pointer type fsc1.c:40: warning: passing argument 2 of ‘cf’ from incompatible pointer type fsc1.c:43: warning: incompatible implicit declaration of built-in function ‘malloc’ fsc1.c:47: warning: incompatible implicit declaration of built-in function ‘free’ fsc1.c: In function ‘main’: fsc1.c:80: error: incompatible types in assignment fsc1.c:82: warning: passing argument 1 of ‘Bubblesort’ from incompatible pointer type

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  • Error: '<method1>' and '<method2>' cannot overload each other

    - by serhio
    I override a list in VB. In C# the code compiles and looks like this: class MyObjectCollection : IList { ... /// <summary> /// Gets or sets the element at the specified index. /// </summary> public MyObject this[int index] { get { return (MyObject)innerArray[index]; } set { innerArray[index] = value; } } ... } in VB.NET I transform: Class MyObjectCollection Implements IList ... ''' <summary> ' ''' Gets or sets the element at the specified index. ' ''' </summary> ' Default Public Overrides Property Item(ByVal index As Integer) As MyObject Get Return DirectCast(innerArray(index), MyObject) End Get Set(ByVal value As MyObject) innerArray(index) = value End Set End Property ... End Class Error: 'Public Overrides Default Property Item(index As Integer) As MyObject' and 'Public Default Property Item(index As Integer) As Object' cannot overload each other because they differ only by return types Whole collection class in C# public class MyObjectCollection : IList { private ArrayList innerArray; public MyObjectCollection() { innerArray = new ArrayList(); } public int Count { get { return innerArray.Count; } } public bool IsFixedSize { get { return false; } } public bool IsReadOnly { get { return false; } } public bool IsSynchronized { get { return false; } } object ICollection.SyncRoot { get { return null; } } public MyObject this[int index] { get { return (MyObject)innerArray[index]; } set { innerArray[index] = value; } } public int Add(MyObject value) { int index = innerArray.Add(value); return index; } public void AddRange(MyObject[] array) { innerArray.AddRange(array); } public void Clear() { innerArray.Clear(); } public bool Contains(MyObject item) { return innerArray.Contains(item); } public bool Contains(string name) { foreach (MyObject spec in innerArray) if (spec.Name == name) return true; return false; } public void CopyTo(MyObject[] array) { innerArray.CopyTo(array); } public void CopyTo(MyObject[] array, int index) { innerArray.CopyTo(array, index); } public IEnumerator GetEnumerator() { return innerArray.GetEnumerator(); } public int IndexOf(MyObject value) { return innerArray.IndexOf(value); } public int IndexOf(string name) { int i = 0; foreach (MyObject spec in innerArray) { if (spec.Name == name) return i; i++; } return -1; } public void Insert(int index, MyObject value) { innerArray.Insert(index, value); } public void Remove(MyObject obj) { innerArray.Remove(obj); } public void Remove(string name) { int index = IndexOf(name); RemoveAt(index); } public void RemoveAt(int index) { innerArray.RemoveAt(index); } public MyObject[] ToArray() { return (MyObject[])innerArray.ToArray(typeof(MyObject)); } #region Explicit interface implementations for ICollection and IList void ICollection.CopyTo(Array array, int index) { CopyTo((MyObject[])array, index); } int IList.Add(object value) { return Add((MyObject)value); } bool IList.Contains(object obj) { return Contains((MyObject)obj); } object IList.this[int index] { get { return ((MyObjectCollection)this)[index]; } set { ((MyObjectCollection)this)[index] = (MyObject)value; } } int IList.IndexOf(object obj) { return IndexOf((MyObject)obj); } void IList.Insert(int index, object value) { Insert(index, (MyObject)value); } void IList.Remove(object value) { Remove((MyObject)value); } #endregion }

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  • Template inheritence c++

    - by Chris Condy
    I have made a template singleton class, I have also made a data structure that is templated. My question is; how do I make my templated data structure inherit from a singleton so you can only have one float type of this structure? I have tested both seperate and have found no problems. Code provided under... (That is the problem) template <class Type> class AbstractRManagers : public Singleton<AbstractRManagers<Type> > The problem is the code above doesn't work I get alot of errors. I cant get it to no matter what I do template a templated singleton class... I was asking for maybe advice or maybe if the code above is incorrect guidence? #ifndef SINGLETON_H #define SINGLETON_H template <class Type> class Singleton { public: virtual ~Singleton(); Singleton(); static Type* m_instance; }; template <class Type> Type* Singleton<Type>::m_instance = 0; #include "Singleton.cpp" #endif #ifndef SINGLETON_CPP #define SINGLETON_CPP #include "Singleton.h" template <class Type> Singleton<Type>::Singleton() { } template <class Type> Singleton<Type>::~Singleton() { } template <class Type> Type* Singleton<Type>::getInstance() { if(m_instance==nullptr) { m_instance = new Type; } return m_instance; } #endif #ifndef ABSTRACTRMANAGERS_H #define ABSTRACTRMANAGERS_H #include <vector> #include <map> #include <stack> #include "Singleton.h" template <class Type> class AbstractRManagers : public Singleton<AbstractRManagers<Type> > { public: virtual ~AbstractRManagers(); int insert(Type* type, std::string name); Type* remove(int i); Type* remove(std::string name); Type* get(int i); Type* getS(std::string name); int get(std::string name); int get(Type* i); bool check(std::string name); int resourceSize(); protected: private: std::vector<Type*> m_resources; std::map<std::string,int> m_map; std::stack<int> m_freePos; }; #include "AbstractRManagers.cpp" #endif #ifndef ABSTRACTRMANAGERS_CPP #define ABSTRACTRMANAGERS_CPP #include "AbstractRManagers.h" template <class Type> int AbstractRManagers<Type>::insert(Type* type, std::string name) { int i=0; if(!check(name)) { if(m_freePos.empty()) { m_resources.push_back(type); i = m_resources.size()-1; m_map[name] = i; } else { i = m_freePos.top(); m_freePos.pop(); m_resources[i] = type; m_map[name] = i; } } else i = -1; return i; } template <class Type> int AbstractRManagers<Type>::resourceSize() { return m_resources.size(); } template <class Type> bool AbstractRManagers<Type>::check(std::string name) { std::map<std::string,int>::iterator it; it = m_map.find(name); if(it==m_map.end()) return false; return true; } template <class Type> Type* AbstractRManagers<Type>::remove(std::string name) { Type* temp = m_resources[m_map[name]]; if(temp!=NULL) { std::map<std::string,int>::iterator it; it = m_map[name]; m_resources[m_map[name]] = NULL; m_freePos.push(m_map[name]); delete (*it).second; delete (*it).first; return temp; } return NULL; } template <class Type> Type* AbstractRManagers<Type>::remove(int i) { if((i < m_resources.size())&&(i > 0)) { Type* temp = m_resources[i]; m_resources[i] = NULL; m_freePos.push(i); std::map<std::string,int>::iterator it; for(it=m_map.begin();it!=m_map.end();it++) { if((*it).second == i) { delete (*it).second; delete (*it).first; return temp; } } return temp; } return NULL; } template <class Type> int AbstractRManagers<Type>::get(Type* i) { for(int i2=0;i2<m_resources.size();i2++) { if(i == m_resources[i2]) { return i2; } } return -1; } template <class Type> Type* AbstractRManagers<Type>::get(int i) { if((i < m_resources.size())&&(i >= 0)) { return m_resources[i]; } return NULL; } template <class Type> Type* AbstractRManagers<Type>::getS(std::string name) { return m_resources[m_map[name]]; } template <class Type> int AbstractRManagers<Type>::get(std::string name) { return m_map[name]; } template <class Type> AbstractRManagers<Type>::~AbstractRManagers() { } #endif #include "AbstractRManagers.h" struct b { float x; }; int main() { b* a = new b(); AbstractRManagers<b>::getInstance()->insert(a,"a"); return 0; } This program produces next errors when compiled : 1> main.cpp 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1> c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(124) : while compiling class template member function 'bool std::less<_Ty>::operator ()(const _Ty &,const _Ty &) const' 1> with 1> [ 1> _Ty=std::string 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\map(71) : see reference to class template instantiation 'std::less<_Ty>' being compiled 1> with 1> [ 1> _Ty=std::string 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(451) : see reference to class template instantiation 'std::_Tmap_traits<_Kty,_Ty,_Pr,_Alloc,_Mfl>' being compiled 1> with 1> [ 1> _Kty=std::string, 1> _Ty=int, 1> _Pr=std::less<std::string>, 1> _Alloc=std::allocator<std::pair<const std::string,int>>, 1> _Mfl=false 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(520) : see reference to class template instantiation 'std::_Tree_nod<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(659) : see reference to class template instantiation 'std::_Tree_val<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\map(81) : see reference to class template instantiation 'std::_Tree<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\users\chris\desktop\311\ideas\idea1\idea1\abstractrmanagers.h(28) : see reference to class template instantiation 'std::map<_Kty,_Ty>' being compiled 1> with 1> [ 1> _Kty=std::string, 1> _Ty=int 1> ] 1> c:\users\chris\desktop\311\ideas\idea1\idea1\abstractrmanagers.h(30) : see reference to class template instantiation 'AbstractRManagers<Type>' being compiled 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2676: binary '<' : 'const std::string' does not define this operator or a conversion to a type acceptable to the predefined operator ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

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  • Finding perfect numbers in C# (optimization)

    - by paradox
    I coded up a program in C# to find perfect numbers within a certain range as part of a programming challenge . However, I realized it is very slow when calculating perfect numbers upwards of 10000. Are there any methods of optimization that exist for finding perfect numbers? My code is as follows: using System; using System.Collections.Generic; using System.Linq; namespace ConsoleTest { class Program { public static List<int> FindDivisors(int inputNo) { List<int> Divisors = new List<int>(); for (int i = 1; i<inputNo; i++) { if (inputNo%i==0) Divisors.Add(i); } return Divisors; } public static void Main(string[] args) { const int limit = 100000; List<int> PerfectNumbers = new List<int>(); List<int> Divisors=new List<int>(); for (int i=1; i<limit; i++) { Divisors = FindDivisors(i); if (i==Divisors.Sum()) PerfectNumbers.Add(i); } Console.Write("Output ="); for (int i=0; i<PerfectNumbers.Count; i++) { Console.Write(" {0} ",PerfectNumbers[i]); } Console.Write("\n\n\nPress any key to continue . . . "); Console.ReadKey(true); } } }

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  • C# and F# lambda expressions code generation

    - by ControlFlow
    Let's look at the code, generated by F# for simple function: let map_add valueToAdd xs = xs |> Seq.map (fun x -> x + valueToAdd) The generated code for lambda expression (instance of F# functional value) will looks like this: [Serializable] internal class map_add@3 : FSharpFunc<int, int> { public int valueToAdd; internal map_add@3(int valueToAdd) { this.valueToAdd = valueToAdd; } public override int Invoke(int x) { return (x + this.valueToAdd); } } And look at nearly the same C# code: using System.Collections.Generic; using System.Linq; static class Program { static IEnumerable<int> SelectAdd(IEnumerable<int> source, int valueToAdd) { return source.Select(x => x + valueToAdd); } } And the generated code for the C# lambda expression: [CompilerGenerated] private sealed class <>c__DisplayClass1 { public int valueToAdd; public int <SelectAdd>b__0(int x) { return (x + this.valueToAdd); } } So I have some questions: Why does F#-generated class is not marked as sealed? Why does F#-generated class contains public fields since F# doesn't allows mutable closures? Why does F# generated class has the constructor? It may be perfectly initialized with the public fields... Why does C#-generated class is not marked as [Serializable]? Also classes generated for F# sequence expressions are also became [Serializable] and classes for C# iterators are not.

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  • Why Java language does not offer a way to declare getters and setters of a given "field" through ann

    - by zim2001
    I actually happily design and develop JEE Applications for quite 9 years, but I realized recently that as time goes by, I feel more and more fed up of dragging all these ugly bean classes with their bunch of getters and setters. Considering a basic bean like this : public class MyBean { // needs getter AND setter private int myField1; // needs only a getter, no setter private int myField2; // needs only a setter, no getter private int myField3; /** * Get the field1 * @return the field1 */ public int getField1() { return myField1; } /** * Set the field1 * @param value the value */ public void setField1(int value) { myField1 = value; } /** * Get the field2 * @return the field2 */ public int getField2() { return myField2; } /** * Set the field3 * @param value the value */ public void setField3(int value) { myField3 = value; } } I'm dreaming of something like this : public class MyBean { @inout(public,public) private int myField1; @out(public) private int myField2; @in(public) private int myField3; } No more stupid javadoc, just tell the important thing... It would still be possible to mix annotation and written down getters or setters, to cover cases when it should do non-trivial sets and gets. In other words, annotation would auto-generate the getter / setter code piece except when a literate one is provided. Moreover, I'm also dreaming of replacing things like that : MyBean b = new MyBean(); int v = b.getField1(); b.setField3(v+1); by such : MyBean b = new MyBean(); int v = b.field1; b.field3 = v+1; In fact, writing "b.field1" on the right side of an expression would be semantically identical to write "b.getField1()", I mean as if it has been replaced by some kind of a preprocessor. It's just an idea but I'm wondering if I'm alone on that topic, and also if it has major flaws. I'm aware that this question doesn't exactly meet the SO credo (we prefer questions that can be answered, not just discussed) so I flag it community wiki...

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  • how to implement intel's tbb::blocked_range2d in C++

    - by Hristo
    I'm trying to parallelize nested for loops with parellel_for() and the blocked_range2d from Intel's TBB using C++. The for loops look like this: for(int i = 0; i < N; ++i) { for(int j = 0; j < E[i]; ++j) { for(int k = 0; k < T; ++k) { score[k] += delta(i, trRating[k][i], exRating[j][i]); } } } ... and I am trying to do the following: class LoopBody { private: int *myscore; public: LoopBody(int *score) { myscore = score; } void operator()(const blocked_range2d<int> &r) const { for(int i = r.rows().begin(); i != r.rows().end(); ++i); for(int j = 0; j < E[i]; ++j) { for(int k = r.cols().begin(); k != r.cols().end(); ++k) { myscore[k] += foo(...); // uses i,j,k to look up indices in arrays } } } } }; void computeScores(int score[]) { parallel_for(blocked_range2d<int>(0, N, 0, T), LoopBody(score)); } ... but I am getting the following compile errors: error: identifier "i" is undefined for(int j = 0; j < E[i]; ++j) { ^ error: expected an identifier }; ^ I'm not really sure if I am doing this the right way, but any advice is appreciated. Also, this is my first time using Intel's TBB so I really don't know anything about it. Any ideas how make this work? Thanks, Hristo

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  • Codechef practice question help needed - find trailing zeros in a factorial

    - by manugupt1
    I have been working on this for 24 hours now, trying to optimize it. The question is how to find the number of trailing zeroes in factorial of a number in range of 10000000 and 10 million test cases in about 8 secs. The code is as follows: #include<iostream> using namespace std; int count5(int a){ int b=0; for(int i=a;i>0;i=i/5){ if(i%15625==0){ b=b+6; i=i/15625; } if(i%3125==0){ b=b+5; i=i/3125; } if(i%625==0){ b=b+4; i=i/625; } if(i%125==0){ b=b+3; i=i/125; } if(i%25==0){ b=b+2; i=i/25; } if(i%5==0){ b++; } else break; } return b; } int main(){ int l; int n=0; cin>>l; //no of test cases taken as input int *T = new int[l]; for(int i=0;i<l;i++) cin>>T[i]; //nos taken as input for the same no of test cases for(int i=0;i<l;i++){ n=0; for(int j=5;j<=T[i];j=j+5){ n+=count5(j); //no of trailing zeroes calculted } cout<<n<<endl; //no for each trialing zero printed } delete []T; } Please help me by suggesting a new approach, or suggesting some modifications to this one.

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  • Setting up DrJava to work through Friedman / Felleisen "A Little Java"

    - by JDelage
    All, I'm going through the Friedman & Felleisen book "A Little Java, A Few Patterns". I'm trying to type the examples in DrJava, but I'm getting some errors. I'm a beginner, so I might be making rookie mistakes. Here is what I have set-up: public class ALittleJava { //ABSTRACT CLASS POINT abstract class Point { abstract int distanceToO(); } class CartesianPt extends Point { int x; int y; int distanceToO(){ return((int)Math.sqrt(x*x+y*y)); } CartesianPt(int _x, int _y) { x=_x; y=_y; } } class ManhattanPt extends Point { int x; int y; int distanceToO(){ return(x+y); } ManhattanPt(int _x, int _y){ x=_x; y=_y; } } } And on the main's side: public class Main{ public static void main (String [] args){ Point y = new ManhattanPt(2,8); System.out.println(y.distanceToO()); } } The compiler cannot find the symbols Point and ManhattanPt in the program. If I precede each by ALittleJava., I get another error in the main, i.e., an enclosing instance that contains ALittleJava.ManhattanPt is required I've tried to find ressources on the 'net, but the book must have a pretty confidential following and I couldn't find much. Thank you all. JDelage

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  • What is the best way to attach extenstion methods to static classes rather than to instances of a cl

    - by John Gietzen
    If I have a method for calculating the greatest common divisor of two integers as: public static int GCD(int a, int b) { return b == 0 ? a : GCD(b, a % b); } What would be the best way to attach that to the System.Math class? Here are the three ways I have come up with: public static int GCD(this int a, int b) { return b == 0 ? a : b.GCD(a % b); } // Lame... var gcd = a.GCD(b); and: public static class RationalMath { public static int GCD(int a, int b) { return b == 0 ? a : GCD(b, a % b); } } // Lame... var gcd = RationalMath.GCD(a, b); and: public static int GCD(this Type math, int a, int b) { return b == 0 ? a : typeof(Math).GCD(b, a % b); } // Neat? var gcd = typeof(Math).GCD(a, b); The desired syntax is Math.GCD since that is the standard for all mathematical functions. Any suggestions? What should I do to get the desired syntax?

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  • What is the best way to attach static methods to classes rather than to instances of a class?

    - by John Gietzen
    If I have a method for calculating the greatest common divisor of two integers as: public static int GCD(int a, int b) { return b == 0 ? a : GCD(b, a % b); } What would be the best way to attach that to the System.Math class? Here are the three ways I have come up with: public static int GCD(this int a, int b) { return b == 0 ? a : b.GCD(a % b); } // Lame... var gcd = a.GCD(b); and: public static class RationalMath { public static int GCD(int a, int b) { return b == 0 ? a : GCD(b, a % b); } } // Lame... var gcd = RationalMath.GCD(a, b); and: public static int GCD(this Type math, int a, int b) { return b == 0 ? a : typeof(Math).GCD(b, a % b); } // Neat? var gcd = typeof(Math).GCD(a, b); The desired syntax is Math.GCD since that is the standard for all mathematical functions. Any suggestions? What should I do to get the desired syntax?

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  • Whats wrong with this piece of code?

    - by cambr
    vector<int>& mergesort(vector<int> &a) { if (a.size() == 1) return a; int middle = a.size() / 2; vector<int>::const_iterator first = a.begin(); vector<int>::const_iterator mid = a.begin() + (middle - 1); vector<int>::const_iterator last = a.end(); vector<int> ll(first, mid); vector<int> rr(mid, last); vector<int> l = mergesort(ll); vector<int> r = mergesort(rr); vector<int> result; result.reserve(a.size()); int dp = 0, lp = 0, rp = 0; while (dp < a.size()) { if (lp == l.size()) { result[dp] = (r[rp]); rp++; } else if (rp == r.size()) { result[dp] = (l[lp]); lp++; } else if (l[lp] < r[rp]) { result[dp] = (l[lp]); lp++; } else { result[dp] = (r[rp]); rp++; } dp++; } a = result; return a; } It compiles coorectly but while execution, I am getting: This application has requested the runtime to end it in an unusual way. This is a weird error. Is there something that is fundamentally wrong with the code?

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  • does sfWidgetFormSelect provide a string or an int of the selected item?

    - by han
    Hey guys, I'm having an annoying problem. I'm trying to find out what fields of a form were changed, and then insert that into a table. I managed to var_dump in doUpdateObjectas shown in the following public function doUpdateObject($values) { parent::doUpdateObject($values); var_dump($this->getObject()->getModified(false)); var_dump($this->getObject()->getModified(true)); } And it seems like $this-getObject()-getModified seems to work in giving me both before and after values by setting it to either true or false. The problem that I'm facing right now is that, some how, sfWidgetFormSelect seems to be saving one of my fields as a string. before saving, that exact same field was an int. (I got this idea by var_dump both before and after). Here is what the results on both var dumps showed: array(1) {["annoying_field"]=> int(3)} array(1) {["annoying_field"]=>string(1)"3"} This seems to cause doctrine to think that this is a modification and thus gives a false positive. In my base form, I have under $this->getWidgets() 'annoying_field' => new sfWidgetFormInputText(), under $this->setValidators 'annoying_field' => new sfValidatorInteger(array('required' => false)), and lastly in my configured Form.class.php I have reconfigured the file as such: $this->widgetSchema['annoying_field'] = new sfWidgetFormSelect(array('choices' => $statuses)); statuses is an array containing values like {""a", "b", "c", "d"} and I just want the index of the status to be stored in the database. And also how can I insert the changes into another database table? let's say my Log table? Any ideas and advice as to why this is happen is appreciated, I've been trying to figure it out and browsing google for various keywords with no avail. Thanks! Edit: ok so I created another field, integer in my schema just for testing. I created an entry, saved it, and edited it. this time the same thing happened!

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  • LINQ Query using UDF that receives parameters from the query

    - by Ben Fidge
    I need help using a UDF in a LINQ which calculates a users position from a fixed point. int pointX = 567, int pointY = 534; // random points on a square grid var q = from n in _context.Users join m in _context.GetUserDistance(n.posY, n.posY, pointX, pointY, n.UserId) on n.UserId equals m.UserId select new User() { PosX = n.PosX, PosY = n.PosY, Distance = m.Distance, Name = n.Name, UserId = n.UserId }; The GetUserDistance is just a UDF that returns a single row in a TVP with that users distance from the points deisgnated in pointX and pointY variables, and the designer generates the following for it: [global::System.Data.Linq.Mapping.FunctionAttribute(Name="dbo.GetUserDistance", IsComposable=true)] public IQueryable<GetUserDistanceResult> GetUserDistance([global::System.Data.Linq.Mapping.ParameterAttribute(Name="X1", DbType="Int")] System.Nullable<int> x1, [global::System.Data.Linq.Mapping.ParameterAttribute(Name="X2", DbType="Int")] System.Nullable<int> x2, [global::System.Data.Linq.Mapping.ParameterAttribute(Name="Y1", DbType="Int")] System.Nullable<int> y1, [global::System.Data.Linq.Mapping.ParameterAttribute(Name="Y2", DbType="Int")] System.Nullable<int> y2, [global::System.Data.Linq.Mapping.ParameterAttribute(Name="UserId", DbType="Int")] System.Nullable<int> userId) { return this.CreateMethodCallQuery<GetUserDistanceResult>(this, ((MethodInfo)(MethodInfo.GetCurrentMethod())), x1, x2, y1, y2, userId); } when i try to compile i get The name 'n' does not exist in the current context

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