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OpenMP vs PThreads for linear programming 14 Years Ago by arthurav The subject of my bachelour thesis is "Solving linear programming problems using parallel algorithms". I will create a library for solving different kinds of problems (simplex, branch and bound and so on). I want to use OpenMP or PThreads locally and OpenMPI in the network. Which one would you recommend for the case: OpenMP or Pthreads? OpenMP For Loop - vector subscript out of range 12 Years Ago by eric.inclan.3 … parallel programming but read about the simplicity of working with OpenMP, and that's what I need. Something that will make… works perfectly fine as soon as I comment out the OpenMP code. For the "pragma" commands, I've tried… OpenMP and Glut problem 16 Years Ago by kuratkull … function which is messed up, either by GCC or by OpenMP. I have GCC 4.3.1 20080626. The problem is… OpenMP on GCC on Ubuntu 12 Years Ago by monmondiesel … GCC to compile this simple C program that has simple OpenMp pragmas : #include <stdio.h> #include <omp.h… trying to optimize with openMP 8 Years Ago by David_94 … but has four virtual cores. I tried to use openMP, and while it runs error free, and appears to…gt;tv_sec; } I have tried many different openMP pragmas inside the openMP version of the function. I have tried heavy … small vector length, and very large, but the openMP version and the single threaded version give essentially the … convert any image to grayscale using openMP 12 Years Ago by ramy.merc … of any type bmp,jpeg,png...etc) to grayscale using openMP. After doing some research, I got the main method which… allows me to do the conversion using openMP, it's as follows: // pDest is an unsigned char array… Re: convert any image to grayscale using openMP 12 Years Ago by ramy.merc Moschops.. thanks a lot for the help. I will check this today and if it is solved by applying openMP, I will check it as solved Re: convert any image to grayscale using openMP 12 Years Ago by Moschops You should put the CImg.h header file somewhere the preprocessor can find it. Do you know what a header file is? Do you know what they are for? In a related question, who is asking you to use openMP without having taught you about header files? game of life with openMP 15 Years Ago by mjee … have written a program for the Game of Life in OpenMP with C. But the execution time is increasing with the… Parallelize md5 code using OpenMP (omp) 12 Years Ago by ziadkassam … all... My project is to parallelize the MD5 program using OpenMP (omp). so please help... This is test.cpp: #include <… Simple sha-1 encryption using openMp 12 Years Ago by n@nnouss@ I have a project and a part of it is related to sha 1 encryption using openMP. Any help would be highly appreciated. Re: Simple sha-1 encryption using openMp 12 Years Ago by Moschops Has a class somewhere suddenly set a number of OpenMP assignments? Re: Simple sha-1 encryption using openMp 12 Years Ago by n@nnouss@ …-1. But I need to use parallel programming in C++ (openMP). This is what I don't know how to do… MD5 parallelizing using OpenMP 12 Years Ago by ziadkassam I need help... I want to parallelize the MD5 algorithm using OpenMP in C++. Parallel program using openmp threading 11 Years Ago by willyah How can write a paralle program using the openmp threading library(omp.h) to calculate the time needed to calculate the dot product of two vectors. Re: OpenMP vs PThreads for linear programming 14 Years Ago by pseudorandom21 I am familiar with neither, though I have used many a C++ library, and using only one or at the most two different libs will help maintain flexibility and minimize problems with the project. I would try to use only one, if possible. Re: OpenMP vs PThreads for linear programming 14 Years Ago by arthurav Thank you. I will use only one of the SMP models but I don't know which one does fit better for the case. Re: OpenMP For Loop - vector subscript out of range 12 Years Ago by mike_2000_17 I'm not sure, but I'm inclined to think that the indices `i` and `j` should be declared within the for-loop statement. Otherwise, each parallel thread will be using the same variable, which is not going to go well. I would try this: #pragma omp parallel { #pragma omp parallel for for (std::size_t i = 0; i < … Re: OpenMP For Loop - vector subscript out of range 12 Years Ago by eric.inclan.3 I did what you suggested and it no longer produces that error. Thank you for your help! Re: OpenMP and Glut problem 16 Years Ago by Aia [CODE]void render(void) { int loop; #pragma omp parallel shared(loop) { #pragma omp for for (loop = 0; loop < 100; loop++) { printf("DIE\n"); _flushlbf (); glVertex2f(loop/50.0,loop/50.0); } } glEnd(); glFlush(); } [/CODE] Invoking glVertex outside of a glBegin/glEnd … Re: OpenMP and Glut problem 16 Years Ago by kuratkull Sorry, I forgot to add these into the testcase, though adding them doesn't work either - the problem persists. The correct(still broken) testcase would then be: [CODE] #include <stdlib.h> #include <GL/glut.h> #include <math.h> #include <omp.h> void render(void) { int loop; glClear(GL_COLOR_BUFFER_BIT); … Re: OpenMP on GCC on Ubuntu 12 Years Ago by monmondiesel Please guys this is urgent !! NO answer up till now ?!?! Re: OpenMP on GCC on Ubuntu 12 Years Ago by Sokurenko use this [Click Here](http://stackoverflow.com/questions/1534912/how-to-build-in-release-mode-with-optimizations-in-gcc) ifeq ($(BUILD),debug) # "Debug" build - no optimization, and debugging symbols CFLAGS += -O0 -g else # "Release" build - optimization, and no debug symbols CFLAGS += -O2 -s -… Re: Confused about pragma for in OpenMP using C++ 9 Years Ago by rubberman Sorry, but I haven't used OpenMP for about 20 years... Try the OpenMP user forums, assuming there are some. FWIW, OpenMP is good to distribute computations over multiple discrete systems, but given today's multi-processor, multi-core systems, threads work a lot better, at least up to a point. openMP firstprivate 11 Years Ago by salah_saleh Hi, I have a problem understanding what is going on in this code: #include <iostream> #include <omp.h> using namespace std; class A { public: A() { cout<<"A created"<<endl; }; ~A() { cout << "A destroyed" << endl;… Re: openMP firstprivate 11 Years Ago by Moschops You're monitoring the default constructor, which is being used once. You're not monitoring the copy constructor as well. Add this to your class to see it: A( const A& other ) { cout<<"A copied"<<endl; } Re: openMP firstprivate 11 Years Ago by salah_saleh Thank you! Re: convert any image to grayscale using openMP 12 Years Ago by Moschops What exactly is it that you don't know how to do? Looks like each pSrc points to the image to change, with each pixel taking 4 bytes (I'd guess RGBA), and you have to read those four numbers and turn them into one new number in the greyscale image. Looks like you've even decided already how to do that conversion - `pDest[z] = (pSrc[z*4+0]*3735 + … Re: convert any image to grayscale using openMP 12 Years Ago by ramy.merc Moschops.. thanks for the reply. What I don't know are the basic stuff, like what to include, how to read the image from hard disk and how to save it. In other words, I have the function above, what are the steps needed to call this function. Thanks in advance Re: convert any image to grayscale using openMP 12 Years Ago by Moschops Pick an imaging library that gives you access to pixel data. CImg is easy to use. Here's simple code that reads pixel values in an image. You could adapt this easily to load up an array and point your `pSrc` at the front. #include "CImg.h" #include <iostream> using namespace cimg_library; int main() {…