Search Results

Search found 5298 results on 212 pages for 'marching cubes algorithm'.

Page 70/212 | < Previous Page | 66 67 68 69 70 71 72 73 74 75 76 77  | Next Page >

  • Geometric Shape Recognition & Find Extreme Points in C#

    - by Apoorv Shah
    Hi, Can anyone tell me how to recognize geometric shape using C#? I have geometric shapes like triangle, hexagon, pentagon, diamond, square,parallelogram, rectangle, etc. I have drawn all these shapes using mspaint. i have one picture box, using opendialog i am selecting any of the geometric shapes, into picturebox. I want to identify the shape of the image & extreme points. As it is hand made image, i want to draw a proper image using extreme points. If anyone has some code or some references, then please send it to me... I need it very very urgently. Thanks, Riya

    Read the article

  • Detecting Asymptotes in a Graph

    - by nasufara
    I am creating a graphing calculator in Java as a project for my programming class. There are two main components to this calculator: the graph itself, which draws the line(s), and the equation evaluator, which takes in an equation as a String and... well, evaluates it. To create the line, I create a Path2D.Double instance, and loop through the points on the line. To do this, I calculate as many points as the graph is wide (e.g. if the graph itself is 500px wide, I calculate 500 points), and then scale it to the window of the graph. Now, this works perfectly for most any line. However, it does not when dealing with asymptotes. If, when calculating points, the graph encounters a domain error (such as 1/0), the graph closes the shape in the Path2D.Double instance and starts a new line, so that the line looks mathematically correct. Example: However, because of the way it scales, sometimes it is rendered correctly, sometimes it isn't. When it isn't, the actual asymptotic line is shown, because within those 500 points, it skipped over x = 2.0 in the equation 1 / (x-2), and only did x = 1.98 and x = 2.04, which are perfectly valid in that equation. Example: In that case, I increased the window on the left and right one unit each. My question is: Is there a way to deal with asymptotes using this method of scaling so that the resulting line looks mathematically correct? I myself have thought of implementing a binary search-esque method, where, if it finds that it calculates one point, and then the next point is wildly far away from the last point, it searches in between those points for a domain error. I had trouble figuring out how to make it work in practice, however. Thank you for any help you may give!

    Read the article

  • How to make ARGB transparency using bitwise operators.

    - by Smejda
    I need to make transparency, having 2 pixels: pixel1: {A, R, G, B} - foreground pixel pixel2: {A, R, G, B} - background pixel A,R,G,B are Byte values each color is represented by byte value now I'm calculating transparency as: newR = pixel2_R * alpha / 255 + pixel1_R * (255 - alpha) / 255 newG = pixel2_G * alpha / 255 + pixel1_G * (255 - alpha) / 255 newB = pixel2_B * alpha / 255 + pixel1_B * (255 - alpha) / 255 but it is too slow I need to do it with bitwise operators (AND,OR,XOR, NEGATION, BIT MOVE)

    Read the article

  • Find a better control

    - by Budda
    It is necessary to implement the following functionality: There is a rectangle "field", its size is 150x100 pixels. Field is split to locations, each location is 10x10 (totally 15x10 locations on the field). There are few "coins" (5, for example), each of them can be dropped into any location. The list of text messages should be displayed in the drop-down list if any coin is clicked (when any message is clicked, drop-down list should be hidden and coin should display the number of selected message from 0 to 9, for example). That should be done with Silverlight 4.0 I am going to implement custom control "Coin", it will have a view (with a circle), it will display some kind of popup-window (please advise, which one), focus will be set to this window. On "FocusLost" window will be closed (without changing message number), if any message from the list will be clicked then its number will be stored inside of coin. Question 1: is there any control that already has required functionality? Question 2: how to implement "drag-and-drop" of coins to the "field" (lets assume, they will be close to the field)? Any thought or ideas will be helpful. Thanks.

    Read the article

  • How to find the longest continuous subsequence whose reverse is also a subsequence

    - by iecut
    Suppose I have a sequence x1,x2,x3.....xn, and I want to find the longest continuous subsequence xi,xi+1,xi+2......xi+k, whose reverse is also a subsequence of the given sequence. And if there are multiple such subsequences, then I also have to find the first. ex:- consider the sequences: abcdefgedcg here i=3 and k=2 aabcdddd here i=5, k=3 I tried looking at the original longest common subsequence problem, but that is used to compare the two sequences to find the longest common subsequence.... but here is only one sequence from which we have to find the subsequences. Please let me know what is the best way to approach this problem, to find the optimal solution.

    Read the article

  • Extend base type and automatically update audit information on Entity

    - by Nix
    I have an entity model that has audit information on every table (50+ tables) CreateDate CreateUser UpdateDate UpdateUser Currently we are programatically updating audit information. Ex: if(changed){ entity.UpdatedOn = DateTime.Now; entity.UpdatedBy = Environment.UserName; context.SaveChanges(); } But I am looking for a more automated solution. During save changes, if an entity is created/updated I would like to automatically update these fields before sending them to the database for storage. Any suggestion on how i could do this? I would prefer to not do any reflection, so using a text template is not out of the question. A solution has been proposed to override SaveChanges and do it there, but in order to achieve this i would either have to use reflection (in which I don't want to do ) or derive a base class. Assuming i go down this route how would I achieve this? For example EXAMPLE_DB_TABLE CODE NAME --Audit Tables CREATE_DATE CREATE_USER UPDATE_DATE UPDATE_USER And if i create a base class public abstract class IUpdatable{ public virtual DateTime CreateDate {set;} public virtual string CreateUser { set;} public virtual DateTime UpdateDate { set;} public virtual string UpdateUser { set;} } The end goal is to be able to do something like... public overrride void SaveChanges(){ //Go through state manager and update audit infromation //FOREACH changed entity in state manager if(entity is IUpdatable){ //If state is created... update create audit. //if state is updated... update update audit } } But I am not sure how I go about generating the code that would extend the interface.

    Read the article

  • Is regex too slow? Real life examples where simple non-regex alternative is better

    - by polygenelubricants
    I've seen people here made comments like "regex is too slow!", or "why would you do something so simple using regex!" (and then present a 10+ lines alternative instead), etc. I haven't really used regex in industrial setting, so I'm curious if there are applications where regex is demonstratably just too slow, AND where a simple non-regex alternative exists that performs significantly (maybe even asymptotically!) better. Obviously many highly-specialized string manipulations with sophisticated string algorithms will outperform regex easily, but I'm talking about cases where a simple solution exists and significantly outperforms regex. What counts as simple is subjective, of course, but I think a reasonable standard is that if it uses only String, StringBuilder, etc, then it's probably simple.

    Read the article

  • n elements in singly linked list

    - by Codenotguru
    The following function is trying to find the nth to last element of a singly linked list. for ex: if the elements are 8-10-5-7-2-1-5-4-10-10 then the result is 7th to last node is 7. Can anybody help me on how this code is working or is there a better and simpler approach? LinkedListNode nthToLast(LinkedListNode head, int n) { if (head == null || n < 1) { return null; } LinkedListNode p1 = head; LinkedListNode p2 = head; for (int j = 0; j < n - 1; ++j) { // skip n-1 steps ahead if (p2 == null) { return null; // not found since list size < n } p2 = p2.next; } while (p2.next != null) { p1 = p1.next; p2 = p2.next; } return p1; }

    Read the article

  • Fastest sort of fixed length 6 int array

    - by kriss
    Answering to another StackOverflow question (this one) I stumbled upon an interresting sub-problem. What is the fastest way to sort an array of 6 ints ? As the question is very low level (will be executed by a GPU): we can't assume libraries are available (and the call itself has it's cost), only plain C to avoid emptying instruction pipeline (that has a very high cost) we should probably minimize branches, jumps, and every other kind of control flow breaking (like those hidden behind sequence points in && or ||). room is constrained and minimizing registers and memory use is an issue, ideally in place sort is probably best. Really this question is a kind of Golf where the goal is not to minimize source length but execution speed. I call it 'Zening` code as used in the title of the book Zen of Code optimization by Michael Abrash and it's sequels.

    Read the article

  • Floodfill with "layers"

    - by user146780
    What I want is to create a vector drawing program with layers, but to avoid using transparency / opacity, I want to draw each shape from lowest layer to highest layer onto a single bitmap. For the filling, I want to floodfill the shape. My issue is that, if I have a shape that is drawn then floodfilled, then the next shape overlaps it a bit and that new shape's border is the same as the other one's then floodfill will only partially fill it. Is there a way given a shape's coordinates that I can find the actual bounds for floodfill rather than use a target color? Thanks

    Read the article

  • How to sort a list so that managers are always ahead of their subordinates

    - by James Black
    I am working on a project using Groovy, and I would like to take an array of employees, so that no manager follows their subordinates in the array. The reason being that I need to add people to a database and I would prefer not to do it in two passes. So, I basically have: <employees> <employee> <employeeid>12</employeeid> <manager>3</manager> </employee> <employee> <employeeid>1</employeeid> <manager></manager> </employee> <employee> <employeeid>3</employeeid> <manager>1</manager> </employee> </employees> So, it should be sorted as such: employeeid = 1 employeeid = 3 employeeid = 12 The first person should have a null for managers. I am thinking about a binary tree representation, but I expect it will be very unbalanced, and I am not certain the best way to do this using Groovy properly. Is there a way to do this that isn't going to involve using nested loops?

    Read the article

  • Pool Billiard AI

    - by Sebi
    Im implementing a pool billiard game in Java and it all works fine. It is a multiplayer game, but nevertheless, it should also be possible to play it alone. For this purpose I'm trying to implement a simple KI. At the moment, the KI choose just randomly a direction and a random intensity of the impulse (don't know the correct english word for that). Of course this AI is very poor and unlikely to ever challenge a player. So i thought about improving the KI, but there are several hard to solve problems. First I thought of just choosing the nearest ball and to try to put it directly into the nearest hole. This isn't that bad, but if there other balls in the line between, it isn't really working anymore. Additionally this dosn't solve te problem of calculating the intensity of the impulse. So are there any general advice? Or any ideas? Best practices?

    Read the article

  • Genetic Programming Online Learning

    - by Lirik
    Has anybody seen a GP implemented with online learning rather than the standard offline learning? I've done some stuff with genetic programs and I simply can't figure out what would be a good way to make the learning process online. Please let me know if you have any ideas, seen any implementations, or have any references that I can look at.

    Read the article

  • Strlen of MAX 16 chars string using bitwise operators

    - by fabrizioM
    The challenge is to find the fastest way to determine in C/C++ the length of a c-string using bitwise operations in C. char thestring[16]; The c-string has a max size of 16 chars and is inside a buffer If the string is equal to 16 chars doesn't have the null byte at the end. I am sure can be done but didn't got it right yet. I am working on this at the moment, but assuming the string is memcpied on a zero-filled buffer. len = buff[0] != 0x0 + buff[1] != 0x0 + buff[2] != 0x0 + buff[3] != 0x0 + buff[4] != 0x0 + buff[5] != 0x0 + buff[6] != 0x0 + buff[7] != 0x0 + buff[8] != 0x0 + buff[9] != 0x0 + buff[10] != 0x0 + buff[11] != 0x0 + buff[12] != 0x0 + buff[13] != 0x0 + buff[14] != 0x0 + buff[15] != 0x0;

    Read the article

  • Compute the Length of Largest substring that starts and ends with the same substring

    - by Deepak
    Hi People, Below is the Problem Statement: PS: Given a string and a non-empty substring sub, compute recursively the largest substring which starts and ends with sub and return its length. Examples: strDist("catcowcat", "cat") ? 9 strDist("catcowcat", "cow") ? 3 strDist("cccatcowcatxx", "cat") ? 9 Below is my Code: (Without recursion)//since i found it hard to implement with recursion. public int strDist(String str, String sub){ int idx = 0; int max; if (str.isEmpty()) max = 0; else max=1; while ((idx = str.indexOf(sub, idx)) != -1){ int previous=str.indexOf(sub, idx); max = Math.max(max,previous); idx++; } return max; } Its working for few as shown below but returns FAIL for others. Expected This Run strDist("catcowcat", "cat") ? 9 6 FAIL strDist("catcowcat", "cow") ? 3 3 OK strDist("cccatcowcatxx", "cat") ? 9 8 FAIL strDist("abccatcowcatcatxyz", "cat") ? 12 12 OK strDist("xyx", "x") ? 3 2 FAIL strDist("xyx", "y") ? 1 1 OK strDist("xyx", "z") ? 0 1 FAIL strDist("z", "z") ? 1 1 OK strDist("x", "z") ? 0 1 FAIL strDist("", "z") ? 0 0 OK strDist("hiHellohihihi", "hi") ? 13 11 FAIL strDist("hiHellohihihi", "hih") ? 5 9 FAIL strDist("hiHellohihihi", "o") ? 1 6 FAIL strDist("hiHellohihihi", "ll") ? 2 4 FAIL Could you let me whats wrong with the code and how to return the largest substring that begins and ends with sub with its respective length.

    Read the article

  • review of a codility test - pair_sum_even_count

    - by geoaxis
    I recently took an online test on codility as part of a recruitment process. I was given two simple problems to solve in 1 hour. For those who don't know codility, its an online coding test site where you can solve ACM style problems in many different languages. if you have 30 or so mins then check this http://codility.com/demo/run/ My weapon of choice is usually Java. So on of the problems I have is as follows (I will try to remember, should have taken a screenshot) Lets say you have array A[0]=1 A[1]=-1 ....A[n]=x Then what would be the smartest way to find out the number of times when A[i]+A[j] is even where i < j So if we have {1,2,3,4,5} we have 1+3 1+5 2+4 3+5 = 4 pairs which are even The code I wrote was some thing along the lines int sum=0; for(int i=0;i<A.length-1;i++){ for (int j=i+1;j<A.length;j++){ if( ((A[i]+A[j])%2) == 0 && i<j) { sum++; } } } There was one more restriction that if the number of pairs is greater than 1e9 then it should retrun -1, but lets forget it. Can you suggest a better solution for this. The number of elements won't exceed 1e9 in normal cases. I think I got 27 points deducted for the above code (ie it's not perfect). Codility gives out a detailed assessment of what went wrong, I don't have that right now.

    Read the article

  • Next month, same day in PHP

    - by Guillermo
    I got a last time (and urgent) requeriment of an "event" that needs to be scheduled the same day of every month. Say of you set the start date on the 1st May you should get the next events on the 1st of Jun, 1 Jul etc. The problem comes with a start date on the 31st (the next ones could be 30 or 28 depending on the month) Considering that there are months with different numbers of days (28,30,31) depending on the month itself and the year... what would ba an easy way to setup this? Consider the following (and flawed) nextmonth function: $events = array() function nextmonth($date) { return $date+(60*60*24*30); } $curr = $start; while($curr < $end) { $events[ = $curr; $curr = nextmonth($curr); } Edited to add: The problem for me is, simply enought, is to solve what the number of days of any given month is and thus get the next corresponding date..

    Read the article

  • Formula needed: Sort array to array-"snaked"

    - by aw
    After the you guys helped me out so gracefully last time, here is another tricky array sorter for you. I have the following array: a = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16] I use it for some visual stuff and render it like this: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Now I want to sort the array to have a "snake" later: // rearrange the array according to this schema 1 2 3 4 12 13 14 5 11 16 15 6 10 9 8 7 // the original array should look like this a = [1,2,3,4,12,13,14,5,11,16,15,6,10,9,8,7] Now I'm looking for a smart formula / smart loop to do that ticker = 0; rows = 4; // can be n cols = 4; // can be n originalArray = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]; newArray = []; while(ticker < originalArray.length) { //do the magic here ticker++; } Thanks again for the help.

    Read the article

  • "Undefined symbols" linker error with simple template class

    - by intregus
    Been away from C++ for a few years and am getting a linker error from the following code: Gene.h #ifndef GENE_H_INCLUDED #define GENE_H_INCLUDED template <typename T> class Gene { public: T getValue(); void setValue(T value); void setRange(T min, T max); private: T value; T minValue; T maxValue; }; #endif // GENE_H_INCLUDED Gene.cpp #include "Gene.h" template <typename T> T Gene<T>::getValue() { return this->value; } template <typename T> void Gene<T>::setValue(T value) { if(value >= this->minValue && value <= this->minValue) { this->value = value; } } template <typename T> void Gene<T>::setRange(T min, T max) { this->minValue = min; this->maxValue = max; } Using Code::Blocks and GCC if it matters to anyone. Also, clearly porting some GA stuff to C++ for fun and practice.

    Read the article

  • Millions of 3D points: How to find the 10 of them closest to a given point?

    - by Kazoom
    A point in 3-d is defined by (x,y,z). Distance d between any two points (X,Y,Z) and (x,y,z) is d= Sqrt[(X-x)^2 + (Y-y)^2 + (Z-z)^2]. Now there are a million entries in a file, each entry is some point in space, in no specific order. Given any point (a,b,c) find the nearest 10 points to it. How would you store the million points and how would you retrieve those 10 points from that data structure.

    Read the article

< Previous Page | 66 67 68 69 70 71 72 73 74 75 76 77  | Next Page >