Search Results

Search found 12044 results on 482 pages for 'foreach loop'.

Page 193/482 | < Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >

• Loops, Recursion and Memoization in JavaScript

  - by Ken Dason

  Originally posted on: http://geekswithblogs.net/kdason/archive/2013/07/25/loops-recursion-and-memoization-in-javascript.aspxAccording to Wikipedia, the factorial of a positive integer n (denoted by n!) is the product of all positive integers less than or equal to n. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120. The value of 0! is 1. We can use factorials to demonstrate iterative loops and recursive functions in JavaScript.  Here is a function that computes the factorial using a for loop: Output: Time Taken: 51 ms Here is the factorial function coded to be called recursively: Output: Time Taken: 165 ms We can speed up the recursive function with the use of memoization.  Hence,  if the value has previously been computed, it is simply returned and the recursive call ends. Output: Time Taken: 17 ms

  Read the article

• What if we run out of stack space in C# or Python?

  - by dotneteer

  Supposing we are running a recursive algorithm on a very large data set that requires, say, 1 million recursive calls. Normally, one would solve such a large problem by converting recursion to a loop and a stack, but what if we do not want to or cannot rewrite the algorithm? Python has the sys.setrecursionlimit(int) method to set the number of recursions. However, this is only part of the story; the program can still run our of stack space. C# does not have a equivalent method. Fortunately, both C# and Python have option to set the stack space when creating a thread. In C#, there is an overloaded constructor for the Thread class that accepts a parameter for the stack size: Thread t = new Thread(work, stackSize); In Python, we can set the stack size by calling: threading.stack_size(67108864) We can then run our work under a new thread with increased stack size.

  Read the article

• Runtime analysis

  - by Joe Smith

  can someone please help me with the analysis of the following function (for inputs of size n). The part that confuses me the most is the inner for loop. def prefix_sums(L): # Total cost = ? pSum = [] #cost = 1 for a in range(len(L)+1): # range + body of function = (n+1) + (n+1)*(body) ? s = 0 #cost = 1 for b in range(a): # cost = ? s = s + L[b] #cost = operation + accessing list = 2 pSum.append(s) #cost = 1 return pSum #cost = 1 What I need to do is figure out the cost of each statement.

  Read the article

• How display path ball will bounce?

  - by boolean

  I'm trying to figure out a way to show the path a ball will travel, so that the player can line up a shot before they fire the ball. I can't think of a way to calculate this path in advance and show it to the player, especially if it involves collision detection. At first I thought I would run the game at a super high speed for one update, plot the path with some dotted lines where the ball bounced, and then in the next frame hide the 'tracer' ball. This seems to have two issues - Calculating collision detection without actually updating the frames and collision detection getting less reliable at high speeds. If they were straight lines I think I could figure this out in a while loop, but trying to take into account the speed of the ball, the curve of the path, the reflecting from other objects..it all seems a bit much. I'm not looking for any code and this isn't a platform specific question, more just help trying to figure out conceptually how this would work. Can this be done? Are there techniques to achieve this?

  Read the article

• Move site from one tld to another

  - by Amol Ghotankar

  If we want to move site from say xyz.com to xyz.org. What all things we need to do to make sure seo works fine. I am doing something like Point both xyz.com and xyz.org to same ip where my site is working Use cannonical url to have xyz.org/* instead of xyz.com/* Add site to webmaster and make a change request. But problem is we are not able to 301 redirect from xyz.com to xyz.org as both are on same i/p and doing so is causing redirect loop and error. How to fix this? Please help.

  Read the article

• Narrow-phase collision detection algorithms

  - by Marian Ivanov

  There are three phases of collision detection. Broadphase: It loops between all objecs that can interact, false positives are allowed, if it would speed up the loop. Narrowphase: Determines whether they collide, and sometimes, how, no false positives Resolution: Resolves the collision. The question I'm asking is about the narrowphase. There are multiple algorithms, differing in complexity and accuracy. Hitbox intersection: This is an a-posteriori algorithm, that has the lowest complexity, but also isn't too accurate, Color intersection: Hitbox intersection for each pixel, a-posteriori, pixel-perfect, not accuratee in regards to time, higher complexity Separating axis theorem: This is used more often, accurate for triangles, however, a-posteriori, as it can't find the edge, when taking last frame in account, it's more stable Linear raycasting: A-priori algorithm, useful for semi-realistic-looking physics, finds the intersection point, even more accurate than SAT, but with more complexity Spline interpolation: A-priori, even more accurate than linear rays, even more coplexity. There are probably many more that I've forgot about. The question is, in when is it better to use SAT, when rays, when splines, and whether there is anything better.

  Read the article

• How can I factor momentum into my space sim?

  - by Josh Petite

  I am trying my hand at creating a simple 2d physics engine right now, and I'm running into some problems figuring out how to incorporate momentum into movement of a spaceship. If I am moving in a given direction at a certain velocity, I am able to currently update the position of my ship easily (Position += Direction * Velocity). However, if the ship rotates at all, and I recalculate the direction (based on the new angle the ship is facing), and accelerate in that direction, how can I take momentum into account to alter the "line" that the ship travels? Currently the ship changes direction instantaneously and continues at its current velocity in that new direction when I press the thrust button. I want it to be a more gradual turning motion so as to give the impression that the ship itself has some mass. If there is already a nice post on this topic I apologize, but nothing came up in my searches. Let me know if any more information is needed, but I'm hoping someone can easily tell me how I can throw mass * velocity into my game loop update.

  Read the article

• Trying to detect collision between two polygons using Separating Axis Theorem

  - by Holly

  The only collision experience i've had was with simple rectangles, i wanted to find something that would allow me to define polygonal areas for collision and have been trying to make sense of SAT using these two links Though i'm a bit iffy with the math for the most part i feel like i understand the theory! Except my implementation somewhere down the line must be off as: (excuse the hideous font) As mentioned above i have defined a CollisionPolygon class where most of my theory is implemented and then have a helper class called Vect which was meant to be for Vectors but has also been used to contain a vertex given that both just have two float values. I've tried stepping through the function and inspecting the values to solve things but given so many axes and vectors and new math to work out as i go i'm struggling to find the erroneous calculation(s) and would really appreciate any help. Apologies if this is not suitable as a question! CollisionPolygon.java: package biz.hireholly.gameplay; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import biz.hireholly.gameplay.Types.Vect; public class CollisionPolygon { Paint paint; private Vect[] vertices; private Vect[] separationAxes; CollisionPolygon(Vect[] vertices){ this.vertices = vertices; //compute edges and separations axes separationAxes = new Vect[vertices.length]; for (int i = 0; i < vertices.length; i++) { // get the current vertex Vect p1 = vertices[i]; // get the next vertex Vect p2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; // subtract the two to get the edge vector Vect edge = p1.subtract(p2); // get either perpendicular vector Vect normal = edge.perp(); // the perp method is just (x, y) => (-y, x) or (y, -x) separationAxes[i] = normal; } paint = new Paint(); paint.setColor(Color.RED); } public void draw(Canvas c, int xPos, int yPos){ for (int i = 0; i < vertices.length; i++) { Vect v1 = vertices[i]; Vect v2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; c.drawLine( xPos + v1.x, yPos + v1.y, xPos + v2.x, yPos + v2.y, paint); } } /* consider changing to a static function */ public boolean intersects(CollisionPolygon p){ // loop over this polygons separation exes for (Vect axis : separationAxes) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // loop over the other polygons separation axes Vect[] sepAxesOther = p.getSeparationAxes(); for (Vect axis : sepAxesOther) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // if we get here then we know that every axis had overlap on it // so we can guarantee an intersection return true; } /* Note projections wont actually be acurate if the axes aren't normalised * but that's not necessary since we just need a boolean return from our * intersects not a Minimum Translation Vector. */ private Vect minMaxProjection(Vect axis) { float min = axis.dot(vertices[0]); float max = min; for (int i = 1; i < vertices.length; i++) { float p = axis.dot(vertices[i]); if (p < min) { min = p; } else if (p > max) { max = p; } } Vect minMaxProj = new Vect(min, max); return minMaxProj; } public Vect[] getSeparationAxes() { return separationAxes; } public Vect[] getVertices() { return vertices; } } Vect.java: package biz.hireholly.gameplay.Types; /* NOTE: Can also be used to hold vertices! Projections, coordinates ect */ public class Vect{ public float x; public float y; public Vect(float x, float y){ this.x = x; this.y = y; } public Vect perp() { return new Vect(-y, x); } public Vect subtract(Vect other) { return new Vect(x - other.x, y - other.y); } public boolean overlap(Vect other) { if( other.x <= y || other.y >= x){ return true; } return false; } /* used specifically for my SAT implementation which i'm figuring out as i go, * references for later.. * http://www.gamedev.net/page/resources/_/technical/game-programming/2d-rotated-rectangle-collision-r2604 * http://www.codezealot.org/archives/55 */ public float scalarDotProjection(Vect other) { //multiplier = dot product / length^2 float multiplier = dot(other) / (x*x + y*y); //to get the x/y of the projection vector multiply by x/y of axis float projX = multiplier * x; float projY = multiplier * y; //we want to return the dot product of the projection, it's meaningless but useful in our SAT case return dot(new Vect(projX,projY)); } public float dot(Vect other){ return (other.x*x + other.y*y); } }

  Read the article

• Fiscal Cliff

  - by Carolyn Cozart

  As December 31, 2012 quickly approaches, so does the deadline to extend the Bush Era Tax Cuts which were extended under the Budget Control Act of 2011.  PeopleSoft realizes that there may be some customer anxiety over the delayed withholding tables. PeopleSoft is unable to move forward with delivering the tax changes until we get the official ruling and withholding tables from the IRS.  Please be assured that our legislative analysts are in the loop and are monitoring this situation daily.  Any changes will be included in a special posting. We have created a Knowledge Document in My Oracle Support, Document ID 1332295.1 to keep you up to date on the pending changes.

  Read the article

• Error in my Separating Axis Theorem collision code

  - by Holly

  The only collision experience i've had was with simple rectangles, i wanted to find something that would allow me to define polygonal areas for collision and have been trying to make sense of SAT using these two links Though i'm a bit iffy with the math for the most part i feel like i understand the theory! Except my implementation somewhere down the line must be off as: (excuse the hideous font) As mentioned above i have defined a CollisionPolygon class where most of my theory is implemented and then have a helper class called Vect which was meant to be for Vectors but has also been used to contain a vertex given that both just have two float values. I've tried stepping through the function and inspecting the values to solve things but given so many axes and vectors and new math to work out as i go i'm struggling to find the erroneous calculation(s) and would really appreciate any help. Apologies if this is not suitable as a question! CollisionPolygon.java: package biz.hireholly.gameplay; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import biz.hireholly.gameplay.Types.Vect; public class CollisionPolygon { Paint paint; private Vect[] vertices; private Vect[] separationAxes; int x; int y; CollisionPolygon(Vect[] vertices){ this.vertices = vertices; //compute edges and separations axes separationAxes = new Vect[vertices.length]; for (int i = 0; i < vertices.length; i++) { // get the current vertex Vect p1 = vertices[i]; // get the next vertex Vect p2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; // subtract the two to get the edge vector Vect edge = p1.subtract(p2); // get either perpendicular vector Vect normal = edge.perp(); // the perp method is just (x, y) => (-y, x) or (y, -x) separationAxes[i] = normal; } paint = new Paint(); paint.setColor(Color.RED); } public void draw(Canvas c, int xPos, int yPos){ for (int i = 0; i < vertices.length; i++) { Vect v1 = vertices[i]; Vect v2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; c.drawLine( xPos + v1.x, yPos + v1.y, xPos + v2.x, yPos + v2.y, paint); } } public void update(int xPos, int yPos){ x = xPos; y = yPos; } /* consider changing to a static function */ public boolean intersects(CollisionPolygon p){ // loop over this polygons separation exes for (Vect axis : separationAxes) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // loop over the other polygons separation axes Vect[] sepAxesOther = p.getSeparationAxes(); for (Vect axis : sepAxesOther) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // if we get here then we know that every axis had overlap on it // so we can guarantee an intersection return true; } /* Note projections wont actually be acurate if the axes aren't normalised * but that's not necessary since we just need a boolean return from our * intersects not a Minimum Translation Vector. */ private Vect minMaxProjection(Vect axis) { float min = axis.dot(new Vect(vertices[0].x+x, vertices[0].y+y)); float max = min; for (int i = 1; i < vertices.length; i++) { float p = axis.dot(new Vect(vertices[i].x+x, vertices[i].y+y)); if (p < min) { min = p; } else if (p > max) { max = p; } } Vect minMaxProj = new Vect(min, max); return minMaxProj; } public Vect[] getSeparationAxes() { return separationAxes; } public Vect[] getVertices() { return vertices; } } Vect.java: package biz.hireholly.gameplay.Types; /* NOTE: Can also be used to hold vertices! Projections, coordinates ect */ public class Vect{ public float x; public float y; public Vect(float x, float y){ this.x = x; this.y = y; } public Vect perp() { return new Vect(-y, x); } public Vect subtract(Vect other) { return new Vect(x - other.x, y - other.y); } public boolean overlap(Vect other) { if(y > other.x && other.y > x){ return true; } return false; } /* used specifically for my SAT implementation which i'm figuring out as i go, * references for later.. * http://www.gamedev.net/page/resources/_/technical/game-programming/2d-rotated-rectangle-collision-r2604 * http://www.codezealot.org/archives/55 */ public float scalarDotProjection(Vect other) { //multiplier = dot product / length^2 float multiplier = dot(other) / (x*x + y*y); //to get the x/y of the projection vector multiply by x/y of axis float projX = multiplier * x; float projY = multiplier * y; //we want to return the dot product of the projection, it's meaningless but useful in our SAT case return dot(new Vect(projX,projY)); } public float dot(Vect other){ return (other.x*x + other.y*y); } }

  Read the article

• Why ISO master (editor) does not read Windows images

  - by Jacek Blocki

  I have the followjng problem with ISO master software: I try to edit WIndows 7 ISO image $ isomaster windows7.iso The file does open, unfortunately all I get is README with message: This disc contains a "UDF" file system and requires an operating system that supports the ISO-13346 "UDF" file system specification. isomaster comes form Ubuntu repository, I am using 12.04. The system has kernel support for UDF installed, I can mount above ISO (mount -o loop) and see its content read only. Any idea how to fix it? Using other than isomaster tool is also an option. Regards, Jacek

  Read the article

• Solving 2D Collision Detection Issues with Relative Velocities

  - by Jengerer

  Imagine you have a situation where two objects are moving parallel to one-another and are both within range to collide with a static wall, like this: A common method used in dynamic collision detection is to loop through all objects in arbitrary order, solve for pair-wise collision detection using relative velocities, and then move the object to the nearest collision, if any. However, in this case, if the red object is checked first against the blue one, it would see that the relative velocity to the blue object is -20 m/s (and would thereby not collide this time frame). Then it would see that the red object would collide with the static wall, and the solution would be: And the red object passes through the blue one. So it appears to be a matter of choosing the right order in which you check collisions; but how can you determine which order is correct? How can this passing through of objects be avoided? Is ignoring relative velocity and considering every object as static during pair-wise checks a better idea for this reason?

  Read the article

• circle - rectangle collision in 2D, most efficient way

  - by john smith

  Suppose I have a circle intersecting a rectangle, what is ideally the least cpu intensive way between the two? method A calculate rectangle boundaries loop through all points of the circle and, for each of those, check if inside the rect. method B calculate rectangle boundaries check where the center of the circle is, compared to the rectangle make 9 switch/case statements for the following positions: top, bottom, left, right top left, top right, bottom left, bottom right inside rectangle check only one distance using the circle's radius depending on where the circle happens t be. I know there are other ways that are definitely better than these two, and if could point me a link to them, would be great but, exactly between those two, which one would you consider to be better, regarding both performance and quality/precision? Thanks in advance.

  Read the article

• Exclude category from Wordpress home page unless it belongs to another category

  - by sirlancelot

  I have multiple users adding content to restricted categories (using RoleScoper) in my Wordpress setup that don't show up on the homepage (custom template with query_posts()). I'm looking for a way to "promote" the submitted content to the homepage by adding it to another category. My loop code looks like this: <?php query_posts($query_string . '&cat=-37'); if (have_posts()): while (have_posts()): the_post(); ?> This will exclude all posts in category 37. However, even if I add the post to a different category it still gets excluded. Is there a way to exclude a post if it belongs to just that one category?

  Read the article

• Need help with this question [closed]

  - by Jaime

  Occasionally, multiplying the sizes of nested loops can give an overestimate for the Big-Oh running time. This result happens when an innermost loop is infrequently executed. Give the Big-O analysis of the running time. Implement the following code and run for several values of N, and compare your analysis with the actual running times. for(int i = 1; i <= n; i++) for(int j = 1; j<=i * i; j++) if(j%i == 0) for(int k = 0; k < j; k++) sum++;

  Read the article

• What does ENDOFMENU do?

  - by Raymond

  I have been given an example program, I am wondering what exactly the <<ENDOFMENU and ENDOFMENU does, won't it work the same if you leave it out and just use the while loop? #!/bin/sh echo "Menu test program..."; stop=0; while test $stop -eq 0; do cat<<ENDOFMENU 1: print the date 2,3 : print the current working directory 4: exit ENDOFMENU echo; echo -e "your choice?\c" read reply echo case $reply in "1") date ;; "2"|"3") pwd ;; "4") stop=1 ;; *) echo illegal choice esac done

  Read the article

• Beginners Guide to Visual Studio LightSwitch makes it easy to take a closer look

  - by Jim Duffy

  Following up on my most recent post about LightSwitch I thought I’d keep you in the loop on a valuable LightSwitch resource. The Beginners Guide to Visual Studio LightSwitch provides a jump start to get you and the department-level-typical-Access-application-developing-power-user rolling with LightSwitch in no time. The guide is broken down into 4 easy to follow parts. Beginners Guide to Visual Studio LightSwitch (Part – 1) – Working with New Data Entry Screen Beginners Guide to Visual Studio LightSwitch (Part – 2) – Working with Search Screen Beginners Guide to Visual Studio LightSwitch (Part – 3) – Working with Editable DataGrid Screen Beginners Guide to Visual Studio LightSwitch (Part – 4) – Working with List and Details Screen I mentioned it in my prior post but don’t forget to check out Beth Massi’s blog for additional information on Visual Studio LightSwitch. Have a day.

  Read the article

• How do I stop stretching during window re-size in XNA?

  - by Bradley Uffner

  In my windowed mode XNA game when the user resizes the window the game stops updating the window and the last frame drawn is stretched and distorted until the user releases the mouse and the resize completes. Is there any way to have the game continue to run "normally", updating frames and redrawing the screen, during the resize event? I realize that keeping the render loop going while resizing may not be possible or recommended due do hardware managed resources getting continually created and destroyed, but is there any way to stop the ugly stretching? Ideally by leaving the existing frame unscaled in the top left, or with a black screen if that isn't possible.

  Read the article

• Implementing a bit shift using AND, NOT, ADD [closed]

  - by fdart17

  I'm implementing a 16-bit left bit shift by r bits, and I only have access to AND, NOT and ADD. There are 3 condition codes, negative, zero and positive, which are set when you use any of these operations. How I went about it was : (1) And the number with 1000 0000 0000 0000 to set condition codes to positive if the most significant bit is 1. (2) Add the number with itself. This shifts bits one to the left. (3) If the MSB was 1, add 1 to the result. (4) Loop threw (1)-(3) r times. I'm wondering if anyone has any hints to some more efficient methods? Thanks!

  Read the article

• Should I be worried if I solve a lot of my problems the same way?

  - by Bryan Harrington

  I really enjoy programming games and puzzle creators/games. I find myself engineering a lot of these problems the same way and ultimately using similar technique to program them that I'm really comfortable with. To give you brief insight, I like to create graphs where nodes are represented with objects. These object hold data such as coordinates, positions and of course references to other neighboring objects. I'll place them all in a data structure and make decisions on this information in a "game loop". While this is a brief example, its not exact in all situations. It's just one way I feel really comfortable with. Is this bad?

  Read the article

• Is it a waste of time to free resources before I exit a process?

  - by Martin

  Let's consider a fictional program that builds a linked list in the heap, and at the end of the program there is a loop that frees all the nodes, and then exits. For this case let's say the linked list is just 500K of memory, and no special space managing is required. Is that a wast of time, because the OS will do that anyway? Will there be a different behavior later? Is that different according to the OS version? I'm mainly interested in UNIX based systems, but any information will be appreciated. I had today my first lesson in OS course and I'm wondering about that now.

  Read the article

• Target tracking with a small delay (actionscript 3.0)

  - by John Dodson

  I'm having trouble thinking of a good method to track my character with an enemy attack. Of course, I don't want the attack to track my character's current position; I want it to track where the character was about 1 second before (so you can move around and make the attack miss and loop around you sort of a thing). The general structure of my game uses a timer to update all of my events. I have a timer going off every 25 milliseconds that updates everything, including my player's position and the enemies position. Right now I just have the enemy attack directly targeting my character....which works fine except that it's impossible to escape =p. Let me know if I didn't supply enough details. My approach was going to basically be get my character's position from about 1 second ago, then have the enemy target that position, the only problem is I can't think of a good way to get my character's position from previous times. Thanks for the help!

  Read the article

• Tips for communication between JS browser game and node.js server?

  - by Petteri Hietavirta

  I am tinkering around with some simple Canvas based cave flyer game and I would like to make it multiplayer eventually. The plan is to use Node.js on the server side. The data sent over would consists of position of each player, direction, velocity and such. The player movements are simple force physics, so I should be able to extrapolate movements before next update from server. Any tips or best practices on the communications side? I guess web sockets are the way to go. Should I send information in every pass of the game loop or with specified intervals? Also, I don't mind if it doesn't work with older browsers.

  Read the article

• Can't disable Alt + mouse buttons combinations

  - by Andrey

  I've already searched through the questions, and didn't find the same question as I want to ask. I'm working in blender and there are some combinations that I am used to and remapping them in blender would be the last resort, not the first. I have tried to disable Alt+LMB and Alt+RMB actions in ccsm, I've tried to do this in dconf or gconf editors as well, but nothing helped. As soon as I close the editors or get back to the main screen of ccsm, these combinations are enabled again. So, for example, instead of selecting an edge loop in blender with Alt+RMB, I get this goddamn menu offering me to move the window to another workspace, etc. I really don't need this function, so I'd rather switch it off instead of remapping the hotkeys I'm used to in blender.

  Read the article

• In which object should I implement wait()/notify()?

  - by Christopher Francisco

  I'm working in an Android project with multithreading. Basically I have to wait to the server to respond before sending more data. The data sending task is delimited by the flag boolean hasServerResponded so the Thread will loop infinitely without doing anything until the flag becomes true. Since this boolean isn't declared as volatile (yet), and also looping without doing anything wastes resources, I thought maybe I should use AtomicBoolean and also implement wait() / notify() mechanism. Should I use the AtomicBoolean object notify() and wait() methods or should I create a lock Object?

  Read the article

< Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >