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  • Deeper Integration with phpBB

    - by The Official Microsoft IIS Site
    More good news on the Interoperability front: the new phpBB release is now available for installation from the Windows Web Application Gallery and Web Platform Installer (Web PI) for Windows, IIS and SQL Server. Version 3.0.7-PL1 of phpBB takes advantage of a number of features for PHP applications on the Microsoft Web Platform with Windows, IIS and SQL Server, including SQL Server Driver for PHP 1.1 , which provides key interoperability for PHP applications to use SQL Server or SQL Azure for data...(read more)

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  • C#/.NET Little Pitfalls: The Dangers of Casting Boxed Values

    - by James Michael Hare
    Starting a new series to parallel the Little Wonders series.  In this series, I will examine some of the small pitfalls that can occasionally trip up developers. Introduction: Of Casts and Conversions What happens when we try to assign from an int and a double and vice-versa? 1: double pi = 3.14; 2: int theAnswer = 42; 3:  4: // implicit widening conversion, compiles! 5: double doubleAnswer = theAnswer; 6:  7: // implicit narrowing conversion, compiler error! 8: int intPi = pi; As you can see from the comments above, a conversion from a value type where there is no potential data loss is can be done with an implicit conversion.  However, when converting from one value type to another may result in a loss of data, you must make the conversion explicit so the compiler knows you accept this risk.  That is why the conversion from double to int will not compile with an implicit conversion, we can make the conversion explicit by adding a cast: 1: // explicit narrowing conversion using a cast, compiler 2: // succeeds, but results may have data loss: 3: int intPi = (int)pi; So for value types, the conversions (implicit and explicit) both convert the original value to a new value of the given type.  With widening and narrowing references, however, this is not the case.  Converting reference types is a bit different from converting value types.  First of all when you perform a widening or narrowing you don’t really convert the instance of the object, you just convert the reference itself to the wider or narrower reference type, but both the original and new reference type both refer back to the same object. Secondly, widening and narrowing for reference types refers the going down and up the class hierarchy instead of referring to precision as in value types.  That is, a narrowing conversion for a reference type means you are going down the class hierarchy (for example from Shape to Square) whereas a widening conversion means you are going up the class hierarchy (from Square to Shape).  1: var square = new Square(); 2:  3: // implicitly convers because all squares are shapes 4: // (that is, all subclasses can be referenced by a superclass reference) 5: Shape myShape = square; 6:  7: // implicit conversion not possible, not all shapes are squares! 8: // (that is, not all superclasses can be referenced by a subclass reference) 9: Square mySquare = (Square) myShape; So we had to cast the Shape back to Square because at that point the compiler has no way of knowing until runtime whether the Shape in question is truly a Square.  But, because the compiler knows that it’s possible for a Shape to be a Square, it will compile.  However, if the object referenced by myShape is not truly a Square at runtime, you will get an invalid cast exception. Of course, there are other forms of conversions as well such as user-specified conversions and helper class conversions which are beyond the scope of this post.  The main thing we want to focus on is this seemingly innocuous casting method of widening and narrowing conversions that we come to depend on every day and, in some cases, can bite us if we don’t fully understand what is going on!  The Pitfall: Conversions on Boxed Value Types Can Fail What if you saw the following code and – knowing nothing else – you were asked if it was legal or not, what would you think: 1: // assuming x is defined above this and this 2: // assignment is syntactically legal. 3: x = 3.14; 4:  5: // convert 3.14 to int. 6: int truncated = (int)x; You may think that since x is obviously a double (can’t be a float) because 3.14 is a double literal, but this is inaccurate.  Our x could also be dynamic and this would work as well, or there could be user-defined conversions in play.  But there is another, even simpler option that can often bite us: what if x is object? 1: object x; 2:  3: x = 3.14; 4:  5: int truncated = (int) x; On the surface, this seems fine.  We have a double and we place it into an object which can be done implicitly through boxing (no cast) because all types inherit from object.  Then we cast it to int.  This theoretically should be possible because we know we can explicitly convert a double to an int through a conversion process which involves truncation. But here’s the pitfall: when casting an object to another type, we are casting a reference type, not a value type!  This means that it will attempt to see at runtime if the value boxed and referred to by x is of type int or derived from type int.  Since it obviously isn’t (it’s a double after all) we get an invalid cast exception! Now, you may say this looks awfully contrived, but in truth we can run into this a lot if we’re not careful.  Consider using an IDataReader to read from a database, and then attempting to select a result row of a particular column type: 1: using (var connection = new SqlConnection("some connection string")) 2: using (var command = new SqlCommand("select * from employee", connection)) 3: using (var reader = command.ExecuteReader()) 4: { 5: while (reader.Read()) 6: { 7: // if the salary is not an int32 in the SQL database, this is an error! 8: // doesn't matter if short, long, double, float, reader [] returns object! 9: total += (int) reader["annual_salary"]; 10: } 11: } Notice that since the reader indexer returns object, if we attempt to convert using a cast to a type, we have to make darn sure we use the true, actual type or this will fail!  If the SQL database column is a double, float, short, etc this will fail at runtime with an invalid cast exception because it attempts to convert the object reference! So, how do you get around this?  There are two ways, you could first cast the object to its actual type (double), and then do a narrowing cast to on the value to int.  Or you could use a helper class like Convert which analyzes the actual run-time type and will perform a conversion as long as the type implements IConvertible. 1: object x; 2:  3: x = 3.14; 4:  5: // if you want to cast, must cast out of object to double, then 6: // cast convert. 7: int truncated = (int)(double) x; 8:  9: // or you can call a helper class like Convert which examines runtime 10: // type of the value being converted 11: int anotherTruncated = Convert.ToInt32(x); Summary You should always be careful when performing a conversion cast from values boxed in object that you are actually casting to the true type (or a sub-type). Since casting from object is a widening of the reference, be careful that you either know the exact, explicit type you expect to be held in the object, or instead avoid the cast and use a helper class to perform a safe conversion to the type you desire. Technorati Tags: C#,.NET,Pitfalls,Little Pitfalls,BlackRabbitCoder

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  • Week in Geek: New Security Hole Found in Windows 8 UEFI ‘Secure Boot’

    - by Asian Angel
    This week’s edition of WIG is filled with news link coverage on topics such as Virgin Mobile USA customers are vulnerable to a password security flaw, Google Chrome will use a single profile on Windows 8, the Raspberry Pi gets a turbo mode, and more. How To Create a Customized Windows 7 Installation Disc With Integrated Updates How to Get Pro Features in Windows Home Versions with Third Party Tools HTG Explains: Is ReadyBoost Worth Using?

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  • Collide with rotation of the object

    - by Lahiru
    I'm developing a mirror for lazer beam(Ball sprite). There I'm trying to redirect the laze beam according to the ration degree of the mirror(Rectangle). How can I collide the ball to the correct angle if the colliding object is with some angle(45 deg) rather than colliding back. here is an screen shot of my work here is my code 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 collision { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; Texture2D ballTexture; Rectangle ballBounds; Vector2 ballPosition; Vector2 ballVelocity; float ballSpeed = 30f; Texture2D blockTexture; Rectangle blockBounds; Vector2 blockPosition; private Vector2 origin; KeyboardState keyboardState; //Font SpriteFont Font1; Vector2 FontPos; private String displayText; public Game1() { graphics = new GraphicsDeviceManager(this); 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 ballPosition = new Vector2(this.GraphicsDevice.Viewport.Width / 2, this.GraphicsDevice.Viewport.Height * 0.25f); blockPosition = new Vector2(this.GraphicsDevice.Viewport.Width / 2, this.GraphicsDevice.Viewport.Height /2); ballVelocity = new Vector2(0, 1); 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); ballTexture = Content.Load<Texture2D>("ball"); blockTexture = Content.Load<Texture2D>("mirror"); //create rectangles based off the size of the textures ballBounds = new Rectangle((int)(ballPosition.X - ballTexture.Width / 2), (int)(ballPosition.Y - ballTexture.Height / 2), ballTexture.Width, ballTexture.Height); blockBounds = new Rectangle((int)(blockPosition.X - blockTexture.Width / 2), (int)(blockPosition.Y - blockTexture.Height / 2), blockTexture.Width, blockTexture.Height); origin.X = blockTexture.Width / 2; origin.Y = blockTexture.Height / 2; // TODO: use this.Content to load your game content here Font1 = Content.Load<SpriteFont>("SpriteFont1"); FontPos = new Vector2(graphics.GraphicsDevice.Viewport.Width - 100, 20); } /// <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> /// private float RotationAngle; float circle = MathHelper.Pi * 2; float angle; 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 //check for collision between the ball and the block, or if the ball is outside the bounds of the screen if (ballBounds.Intersects(blockBounds) || !GraphicsDevice.Viewport.Bounds.Contains(ballBounds)) { //we have a simple collision! //if it has hit, swap the direction of the ball, and update it's position ballVelocity = -ballVelocity; ballPosition += ballVelocity * ballSpeed; } else { //move the ball a bit ballPosition += ballVelocity * ballSpeed; } //update bounding boxes ballBounds.X = (int)ballPosition.X; ballBounds.Y = (int)ballPosition.Y; blockBounds.X = (int)blockPosition.X; blockBounds.Y = (int)blockPosition.Y; keyboardState = Keyboard.GetState(); float val = 1.568017f/90; if (keyboardState.IsKeyDown(Keys.Space)) RotationAngle = RotationAngle + (float)Math.PI; if (keyboardState.IsKeyDown(Keys.Left)) RotationAngle = RotationAngle - val; angle = (float)Math.PI / 4.0f; // 90 degrees RotationAngle = angle; // RotationAngle = RotationAngle % circle; displayText = RotationAngle.ToString(); 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(); // Find the center of the string Vector2 FontOrigin = Font1.MeasureString(displayText) / 2; spriteBatch.DrawString(Font1, displayText, FontPos, Color.White, 0, FontOrigin, 1.0f, SpriteEffects.None, 0.5f); spriteBatch.Draw(ballTexture, ballPosition, Color.White); spriteBatch.Draw(blockTexture, blockPosition,null, Color.White, RotationAngle,origin, 1.0f, SpriteEffects.None, 0f); spriteBatch.End(); base.Draw(gameTime); } } }

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  • How can I automatically switch to USB headset when plugged in?

    - by d3vid
    Whenever I plugged in my old audio jack headset, sound was immediately diverted from my speakers to the headset speakers, and the microphone was immediately available. When I plug in my new USB headset, I have to open Sound Preferences and switch both input and output to the headset. Is there any way to make this happen automatically? I'm using a Fujitsu-Siemens Amilo Pi laptop, Maverick and a Logitech H330 USB headset.

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  • Android, how important is deltaTime?

    - by iQue
    Im making a game that is getting pretty big and sometimes my thread has to skip a frame, so far I'm not using deltaTime for setting the speed of my different objects in the game because it's still not a big enough game for it to matter imo. But its getting bigger then I planned, so my question is, how important is delta Time? If I should use delta time there is a problem, since speedX and speedY are integers(they have to be for eclipse to let you make a rectangle of them), I cant add delta time very functionally as far as I understand, but might be wrong? Ive tried adding deltaTime to the code below, and sometimes my enemies just not move after spawn, they just stand there and run in the same place Will add an some code for how I set / use speed: public void update(int dx, int dy) { double theta = 180.0 / Math.PI * Math.atan2(-(y - controls.pointerPosition.y), controls.pointerPosition.x - x); x +=dx * Math.cos(Math.toRadians(theta)); y +=dy * Math.sin(Math.toRadians(theta)); currentFrame = ++currentFrame % BMP_COLUMNS; } public void draw(Canvas canvas) { int srcX = currentFrame * width; int srcY = 1 * height; Rect src = new Rect(srcX, srcY, srcX + width, srcY + height); Rect dst = new Rect(x, y, x + width, y + height); canvas.drawBitmap(bitmap, src, dst, null); } So if someone with some experience with this has any thoughts, please share. Thank you! Changed code: public void update(int dx, int dy, float delta) { double theta = 180.0 / Math.PI * Math.atan2(-(y - controls.pointerPosition.y), controls.pointerPosition.x - x); double speedX = delta * dx * Math.cos(Math.toRadians(theta)); double speedY = delta * dy * Math.sin(Math.toRadians(theta)); x += speedX; y += speedY; currentFrame = ++currentFrame % BMP_COLUMNS; } public void draw(Canvas canvas) { int srcX = currentFrame * width; int srcY = 1 * height; Rect src = new Rect(srcX, srcY, srcX + width, srcY + height); Rect dst = new Rect(x, y, x + width, y + height); canvas.drawBitmap(bitmap, src, dst, null); } with this code my enemies move like before, except they wont move to the right (wont increment x), all other directions work.

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  • rotate sprite and shooting bullets from the end of a cannon

    - by Alberto
    Hi all i have a problem in my Andengine code, I need , when I touch the screen, shoot a bullet from the cannon (in the same direction of the cannon) The cannon rotates perfectly but when I touch the screen the bullet is not created at the end of the turret This is my code: private void shootProjectile(final float pX, final float pY){ int offX = (int) (pX-canon.getSceneCenterCoordinates()[0]); int offY = (int) (pY-canon.getSceneCenterCoordinates()[1]); if (offX <= 0) return ; if(offY>=0) return; double X=canon.getX()+canon.getWidth()*0,5; double Y=canon.getY()+canon.getHeight()*0,5 ; final Sprite projectile; projectile = new Sprite( (float) X, (float) Y, mProjectileTextureRegion,this.getVertexBufferObjectManager() ); mMainScene.attachChild(projectile); int realX = (int) (mCamera.getWidth()+ projectile.getWidth()/2.0f); float ratio = (float) offY / (float) offX; int realY = (int) ((realX*ratio) + projectile.getY()); int offRealX = (int) (realX- projectile.getX()); int offRealY = (int) (realY- projectile.getY()); float length = (float) Math.sqrt((offRealX*offRealX)+(offRealY*offRealY)); float velocity = (float) 480.0f/1.0f; float realMoveDuration = length/velocity; MoveModifier modifier = new MoveModifier(realMoveDuration,projectile.getX(), realX, projectile.getY(), realY); projectile.registerEntityModifier(modifier); } @Override public boolean onSceneTouchEvent(Scene pScene, TouchEvent pSceneTouchEvent) { if (pSceneTouchEvent.getAction() == TouchEvent.ACTION_MOVE){ double dx = pSceneTouchEvent.getX() - canon.getSceneCenterCoordinates()[0]; double dy = pSceneTouchEvent.getY() - canon.getSceneCenterCoordinates()[1]; double Radius = Math.atan2(dy,dx); double Angle = Radius * 180 / Math.PI; canon.setRotation((float)Angle); return true; } else if (pSceneTouchEvent.getAction() == TouchEvent.ACTION_DOWN){ final float touchX = pSceneTouchEvent.getX(); final float touchY = pSceneTouchEvent.getY(); double dx = pSceneTouchEvent.getX() - canon.getSceneCenterCoordinates()[0]; double dy = pSceneTouchEvent.getY() - canon.getSceneCenterCoordinates()[1]; double Radius = Math.atan2(dy,dx); double Angle = Radius * 180 / Math.PI; canon.setRotation((float)Angle); shootProjectile(touchX, touchY); } return false; } Anyone know how to calculate the coordinates (X,Y) of the end of the barrel to draw the bullet?

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  • JavaOne 2013: (Key) Notes of a conference – State of the Java platform and all the roadmaps by Amis

    - by JuergenKress
    Last week’s JavaOne conference provided insights in the roadmap of the Java platform as well as in the current state of things in the Java community. The close relationship between Oracle and IBM concerning Java, the (continuing) lack of such a relationship with Google, the support from Microsoft for Java applications on its Azure cloud and the vibrant developer community – with over 200 different Java User Groups in many countries of the world. There were no major surprises or stunning announcements. Java EE 7 (release in June) was celebrated, the progress of Java 8 SE explained as well as the progress on Java Embedded and ME. The availability of NetBeans 7.4 RC1 and JDK 8 Early Adopters release as well as the open sourcing of project Avatar probably were the only real news stories. The convergence of JavaFX and Java SE is almost complete; the upcoming alignment of Java SE Embedded and Java ME is the next big consolidation step that will lead to a unified platform where developers can use the same skills, development tools and APIs on EE, SE, SE Embedded and ME development. This means that anything that runs on ME will run on SE (Embedded) and EE – not necessarily the reverse because not all SE APIs are part of the compact profile or the ME environment. However, the trimming down of the SE libraries and the increased capabilities of devices mean that a pretty rich JVM runs on many devices – such as JavaFX 8 on the Raspberry PI. The major theme of the conference was Internet of Things. A world of things that are smart and connected, devices like sensors, cameras and equipment from cars, fridges and television sets to printers, security gates and kiosks that all run Java and are all capable of sending data over local network connections or directly over the internet. The number of devices that has these capabilities is rapidly growing. This means that the number of places where Java programs can help program the behavior of devices is growing too. It also means that the volume of data generated is expanding and that we have to find ways to harvest that data, possibly do a local pre-processing (filter, aggregate) and channel the data to back end systems. Terms typically used are edge devices (small, simple, publishing data), gateways (receiving data from many devices, collecting and consolidating, pre-processing, sending onwards to back end – typically using real time event processing) and enterprise services – receiving the data-turned-information from the gateways to further consolidate, distribute and act upon. A cheap device like the Raspberry PI is a perfect way to get started as a Java developer with what embedded (device) programming means and how interaction with physical input and output takes place. Roadmaps The over all progress on Java is visualized in this overview: Read the full article here. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: Amis,OOW,Oracle OpenWorld,JavaOne,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • How do I host node.js apps with pm2 without running them as root?

    - by jishi
    I have setup pm2 to run a node.js application, and I can successfully start it and it will resurrect upon reboot. However, the pm2 daemon is ran as root, which makes me think that all my node-scripts also runs as root? Even though I added them as a regular user in the system. The log files and stuff is created in the users home dir, /~/.pm2/logs, but the logs are owned by root. when I invoke pm2 startup (which handles the installation of the init.d script etc), it creates /etc/init.d/pm2-init.sh which looks like this: #!/bin/bash # chkconfig: 2345 98 02 # # description: PM2 next gen process manager for Node.js # processname: pm2 # ### BEGIN INIT INFO # Provides: pm2 # Required-Start: # Required-Stop: # Should-Start: # Should-Stop: # Default-Start: 2 3 4 5 # Default-Stop: 0 1 6 # Short-Description: PM2 init script # Description: PM2 is the next gen process manager for Node.js ### END INIT INFO NAME=pm2 PM2=/usr/local/lib/node_modules/pm2/bin/pm2 NODE=/usr/local/bin/node export HOME="/root" start() { echo "Starting $NAME" $NODE $PM2 stopAll $NODE $PM2 resurrect } stop() { $NODE $PM2 dump $NODE $PM2 stopAll } restart() { echo "Restarting $NAME" stop start } status() { echo "Status for $NAME:" $NODE $PM2 list RETVAL=$? } case "$1" in start) start ;; stop) stop ;; status) status ;; restart) restart ;; *) echo "Usage: {start|stop|status|restart}" exit 1 ;; esac exit $RETVAL When I dump the processes (which is what it will use when resurrecting the processes), I see mentions of user "USER":"pi" but I don't think that it's actually run as user pi. Any thoughts?

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  • Python - calculate multinomial probability density functions on large dataset?

    - by Seafoid
    Hi, I originally intended to use MATLAB to tackle this problem but the inbuilt functions has limitations that do not suit my goal. The same limitation occurs in NumPy. I have two tab-delimited files. The first is a file showing amino acid residue, frequency and count for an in-house database of protein structures, i.e. A 0.25 1 S 0.25 1 T 0.25 1 P 0.25 1 The second file consists of quadruplets of amino acids and the number of times they occur, i.e. ASTP 1 Note, there are 8,000 such quadruplets. Based on the background frequency of occurence of each amino acid and the count of quadruplets, I aim to calculate the multinomial probability density function for each quadruplet and subsequently use it as the expected value in a maximum likelihood calculation. The multinomial distribution is as follows: f(x|n, p) = n!/(x1!*x2!*...*xk!)*((p1^x1)*(p2^x2)*...*(pk^xk)) where x is the number of each of k outcomes in n trials with fixed probabilities p. n is 4 four in all cases in my calculation. I have created three functions to calculate this distribution. # functions for multinomial distribution def expected_quadruplets(x, y): expected = x*y return expected # calculates the probabilities of occurence raised to the number of occurrences def prod_prob(p1, a, p2, b, p3, c, p4, d): prob_prod = (pow(p1, a))*(pow(p2, b))*(pow(p3, c))*(pow(p4, d)) return prob_prod # factorial() and multinomial_coefficient() work in tandem to calculate C, the multinomial coefficient def factorial(n): if n <= 1: return 1 return n*factorial(n-1) def multinomial_coefficient(a, b, c, d): n = 24.0 multi_coeff = (n/(factorial(a) * factorial(b) * factorial(c) * factorial(d))) return multi_coeff The problem is how best to structure the data in order to tackle the calculation most efficiently, in a manner that I can read (you guys write some cryptic code :-)) and that will not create an overflow or runtime error. To data my data is represented as nested lists. amino_acids = [['A', '0.25', '1'], ['S', '0.25', '1'], ['T', '0.25', '1'], ['P', '0.25', '1']] quadruplets = [['ASTP', '1']] I initially intended calling these functions within a nested for loop but this resulted in runtime errors or overfloe errors. I know that I can reset the recursion limit but I would rather do this more elegantly. I had the following: for i in quadruplets: quad = i[0].split(' ') for j in amino_acids: for k in quadruplets: for v in k: if j[0] == v: multinomial_coefficient(int(j[2]), int(j[2]), int(j[2]), int(j[2])) I haven'te really gotten to how to incorporate the other functions yet. I think that my current nested list arrangement is sub optimal. I wish to compare the each letter within the string 'ASTP' with the first component of each sub list in amino_acids. Where a match exists, I wish to pass the appropriate numeric values to the functions using indices. Is their a better way? Can I append the appropriate numbers for each amino acid and quadruplet to a temporary data structure within a loop, pass this to the functions and clear it for the next iteration? Thanks, S :-)

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  • How can I walk through two files simultaneously in Perl?

    - by Alex Reynolds
    I have two text files that contain columnar data of the variety position-value, sorted by position. Here is an example of the first file (file A): 100 1 101 1 102 0 103 2 104 1 ... Here is an example of the second file (B): 20 0 21 0 ... 100 2 101 1 192 3 193 1 ... Instead of reading one of the two files into a hash table, which is prohibitive due to memory constraints, what I would like to do is walk through two files simultaneously, in a stepwise fashion. What this means is that I would like to stream through lines of either A or B and compare position values. If the two positions are equal, then I perform a calculation on the values associated with that position. Otherwise, if the positions are not equal, I move through lines of file A or file B until the positions are equal (when I again perform my calculation) or I reach EOF of both files. Is there a way to do this in Perl?

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  • Loose Coupling vs. Information Hiding and Ease of Change

    - by cretzel
    I'm just reading Code Complete by Steve McConell and I'm thinking of an Example he gives in a section about loose coupling. It's about the interface of a method that calculates the number of holidays for an employee, which is calculated from the entry date of the employee and her sales. The author suggests a to have entry date and sales as the parameters of the method instead of an instance of the employee: int holidays(Date entryDate, Number sales) instead of int holidays(Employee emp) The argument is that this decouples the client of the method because it does not need to know anything about the Employee class. Two things came to my mind: Providing all the parameters that are needed for the calculation breaks encapsulation. It shows the internals of the method on how it computes the result. It's harder to change, e.g. when someone decides that also the age of the employee should be included in the calculation. One would have to change the signature. What's your opinion?

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  • Embed a Python persistance layer into a C++ application - good idea?

    - by Rickard
    say I'm about to write an application with a thin GUI layer, a really fat calculation layer (doing computationally heavy calibrations and other long-running stuff) and fairly simple persistance layer. I'm looking at building the GUI + calculation layer in C++ (using Qt for the gui parts). Now - would it be a crazy idea to build the persistance layer in Python, using sqlalchemy, and embed it into the C++ application, letting the layers interface with eachother through lightweigth data transfer objects (written in C++ but accessible from python)? (the other alternative I'm leaning towards would probably be to write the app in Python from the start, using the PyQt wrapper, and then calling into C++ for the computational tasks) Thanks, Rickard

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  • How to compare two TXT files before send it to SQL

    - by adopilot
    I have to handle TXT dat files which coming from one embed device, My problem is in that device always sending all captured data but I want to take only difrences between two sending and do calculation on them. After calculation I send it to SQL using bulkinsert function. I want to extract data which is different according to first file I got from device. Lats say that device first time device send data like this in some.dat (ASCII) file 0000199991 0000199321 0000132913 0000232318 0000312898 On second calls to get data from device it is going to return all again (previous and next captured records) something like this 0000199991 0000199321 0000132913 0000232318 0000312898 9992129990 8782999022 2323423456 But this time I do want only to calculate and pass trough data added after first insert. I am trying to make Win Forms app using C# and Visual Studio 2008

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  • Decimal Value is Zero when it should be 0.0x

    - by Mike Wills
    If this was previously talked about, I'm sorry, I had a hard time searching on this. I am calculating a depreciation rate. One portion of our calculation is 1/life in months. My table stores this data in a decimal field. I tried test = 1 / estimatedLife; but the result of the calculation of test (which is defined as a decimal) is 0. Say the estimated life is 36 months. So 1/36 should equal 0.02777778. Any thoughts of what I am doing wrong? BTW, I changed the test to a double and had the same result.

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  • Embedding .net remoting program in WEB

    - by flufferok
    So, here is a deal. I have client-server application(dotNet remoting). Client side has few trackbars, checkboxes, buttons and picturebox. Server is a console application and does only calculation from client. Client's picturebox make some visualisation of calculation in picturebox. All calulations and relative classes are in dll file. Now I have to embed client application in web site. All kind of technologies are accepted, but I want to minimize forces applied to embedding. So, what is the best way to do embedding?

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  • How to walk through two files simultaneously in Perl?

    - by Alex Reynolds
    I have two text files that contain columnar data of the variety position-value. Here is an example of the first file (file A): 100 1 101 1 102 0 103 2 104 1 ... Here is an example of the second file (B): 20 0 21 0 ... 100 2 101 1 192 3 193 1 ... Instead of reading one of the two files into a hash table, which is prohibitive due to memory constraints, what I would like to do is walk through two files simultaneously, in a stepwise fashion. What this means is that I would like to stream through lines of either A or B and compare position values. If the two positions are equal, then I perform a calculation on the values associated with that position. Otherwise, if the positions are not equal, I move through lines of file A or file B until the positions are equal (when I again perform my calculation) or I reach EOF of both files. Is there a way to do this in Perl?

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  • WPF Dispatcher {"The calling thread cannot access this object because a different thread owns it."}

    - by user359446
    first I need to say that I´m noob with WPF and C#. Application: Create Mandelbrot Image (GUI) My disptacher works perfektly this this case: private void progressBarRefresh(){ while ((con.Progress) < 99) { progressBar1.Dispatcher.Invoke(DispatcherPriority.Send, new Action(delegate { progressBar1.Value = con.Progress; } )); } } I get the Message (Title) when tring to do this with the below code: bmp = BitmapSource.Create(width, height, 96, 96, pf, null, rawImage, stride); this.Dispatcher.Invoke(DispatcherPriority.Send, new Action(delegate { img.Source = bmp; ViewBox.Child = img; //vllt am schluss } )); I will try to explain how my program works. I created a new Thread (because GUI dont response) for the calculation of the pixels and the colors. In this Thread(Mehtod) I´m using the Dispatcher to Refresh my Image in the ViewBox after the calculations are ready. When I´m dont put the calculation in a seperate Thread then I can refresh or build my Image.

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  • Division to the nearest 1 decimal place without floating point math?

    - by John Sheares
    I am having some speed issues with my C# program and identified that this percentage calculation is causing a slow down. The calculation is simply n/d * 100. Both the numerator and denominator can be any integer number. The numerator can never be greater than the denominator and is never negative. Therefore, the result is always from 0-100. Right now, this is done by simply using floating point math and is somewhat slow, since it's being calculated tens of millions of times. I really don't need anything more accurate than to the nearest 0.1 percent. And, I just use this calculated value to see if it's bigger than a fixed constant value. I am thinking that everything should be kept as an integer, so the range with 0.1 accuracy would be 0-1000. Is there some way to calculate this percentage without floating point math?

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  • C++ this as thread parameter, variables unavailable

    - by brecht
    I have three classes: class Rtss_Generator { int mv_transfersize; } class Rtss_GenSine : Rtss_Generator class Rtss_GenSineRpm : Rtss_GenSine Rtss_GenSine creates a thread in his constructer, it is started immediatly and the threadfunction is off-course declared static, waiting for an event to start calculating. the problem: all the variables that are accessed through the gen-pointer are 0, but it does not fail. Also, this-address in the constructer and the gen-pointer-address in the thread are the same, so the pointer is ok. this code is created and compile in visual studio 6.0 service pack 2003 ORIGINAL CODE no thread Rtss_GenSine::getNextData() { //[CALCULATION] //mv_transferSize is accessible and has ALWAYS value 1600 which is ok } NEW CODE Rtss_GenSine::Rtss_GenSine() { createThread(NULL, threadFunction, (LPVOID) this,0,0); } Rtss_GenSine::getNextData() { SetEvent(startCalculating); WaitForSingleObject(stoppedCalculaing, INFINITE); } DWORD Rtss_GenSine::threadFunction(LPVOID pParam) { Rtss_GenSine* gen = (Rtss_GenSine*) pParam; while(runThread) { WaitForSingleObject(startCalculating, INFINITE); ResetEvent(startCalculating) //[CALCULATION] //gen->mv_transferSize ---> it does not fail, but is always zero //all variables accessed via the gen-pointer are 0 setEvent(stoppedCalculaing) } }

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  • design using a readonly class in c#

    - by edosoft
    Hi Small design question here. I'm trying to develop a calculation app in C#. I have a class, let's call it InputRecord, which holds 100s of fields (multi dimensional arrays) This InputRecordclass will be used in a number of CalculationEngines. Each CalculcationEngine can make changes to a number of fields in the InputRecord. These changes are steps needed for it's calculation. Now I don't want the local changes made to the InputRecord to be used in other CalculcationEngine's classes. The first solution that comes to mind is using a struct: these are value types. However I'd like to use inheritance: each CalculationEngine needs a few fields only relevant to that engine: it's has it's own InputRecord, based on BaseInputRecord. Can anyone point me to a design that will help me accomplish this?

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  • Before after select event validation and results with jquery

    - by richbyte
    I am using a javascript function (F) (jquery )which uses 3 select values selected by the user to calculates a value - R(result) R is a number ranging from (1 through 9), (11) and (22); I need 2 extra steps one before the calculation and one after. a. Before calculation takes place: Make sure all three select values are changed before function(F) takes place. If not prompt the user with a notice ( create dom element/ I am using jquery) b. After the value R is calculated show an element corresponding to the result e.g. if R is 1 show an element ( a predetermined "link" element corresponding to each result value) thanks a lot.

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