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I’m trying to parallelize an activity using OpenMp. I having problems because after the first is the code below the result shows wrong.
#include <stdio.h>
#include <fstream>
#include <sstream>
#include <omp.h>
#include <cstdlib>
#include <iostream>
using namespace std;
int countLines(ifstream &file) {
int count = 0;
for (string line; getline(file, line); ) {
count++;
}
return count;
}
float maxErrorCriteria(float *array, int arraySize) {
float max = 0;
#pragma omp parallel for
for (int i = 0; i < arraySize; i++) {
#pragma omp critical
if (array[i] > max) {
max = array[i];
}
}
return max;
}
void invertSignal(float *array) {
*array == 0 ? 0 : *array *= -1;
}
int arrayPosition(int line, int column, int columnCount) {
return (((line) * (columnCount)) + column);
}
void alocateArray(float **array, int size) {
*array = new float[size];
}
void cleanArray(float *array, int size) {
int i;
#pragma omp parallel for private(i)
for (i = 0; i < size; i++) {
array[i] = 0;
}
}
int main() {
ifstream file;
int matrixSize = 0;
int row = 0;
int column = 0;
int i = 0;
int j = 0;
int pos = 0;
float *variableArray;
float *constantArray;
float *errorArray;
float *errorArrayAux;
float const STOP_CRITERIA = 0.001;
string filename = "matriz.txt";
// abrindo o arquivo
file.open(filename.c_str());
// buscando o numero de linhas
row = countLines(file);
// criando vetor dos valores das constantes 1 / diagonal principal
alocateArray(&constantArray, row);
cleanArray(constantArray, row);
// calculando o tamanho da matriz
column = row + 1;
matrixSize = row * column;
// criando vetor valores da matriz
alocateArray(&variableArray, matrixSize);
cleanArray(variableArray, matrixSize);
// reposicionando o arquivo no inicio
file.clear();
file.seekg(0, file.beg);
// populando o vetor de variveis
#pragma omp parallel shared(i, j, pos, variableArray)
#pragma omp parallel for
for(i = 0; i < row; i++) {
for (j = 0; j < column; j++) {
pos = arrayPosition(i, j, column);
file >> variableArray[pos];
}
}
pos = 0;
// populando o vetor de constantes
#pragma omp parallel for private(i, pos) shared(constantArray, variableArray)
for(i = 0; i < row; i++) {
pos = arrayPosition(i, i, column);
constantArray[i] = (1 / variableArray[pos]);
variableArray[pos] = 0;
}
// invertendo o sinal
#pragma omp parallel for private (i, j, pos) shared(variableArray)
for(i = 0; i < row; i++) {
for (j = 0; j < (column - 1); j++) {
pos = arrayPosition(i, j, column);
invertSignal(&variableArray[pos]);
}
}
// fechado o arquivo
file.close();
// criando vetor da margem de erro valores da matriz
alocateArray(&errorArray, row);
cleanArray(errorArray, row);
// criando vetor auxiliar da margem de erro valores da matriz
alocateArray(&errorArrayAux, row);
cleanArray(errorArrayAux, row);
float higherCriteria = 0;
do {
for(i = 0; i < row; i++) {
for (j = 0; j < (column - 1); j++) {
pos = arrayPosition(i, j, column);
errorArrayAux[i] += variableArray[pos] * errorArray[j];
}
pos = arrayPosition(i, j, column);
errorArrayAux[i] += variableArray[pos];
errorArrayAux[i] *= constantArray[i];
}
// copiando os valores
memcpy(errorArray, errorArrayAux, row * sizeof(float));
// localizando o maior
higherCriteria = maxErrorCriteria(errorArray, row);
for(int cu = 0; cu < row; cu++) {
cout << "x"<< (cu+1) << " " << errorArrayAux[cu] << "\n";
}
cout << "\n";
// limpando o vetor
cleanArray(errorArrayAux, row);
} while(STOP_CRITERIA > (1 - higherCriteria));
for(int i = 0; i < row; i++) {
for (int j = 0; j < column; j++) {
pos = arrayPosition(i, j, column);
cout << variableArray[pos] << " ";
}
cout << "\n";
}
system("PAUSE");
}
The process is as follows, in the first for I populate the array with contents of a file, it works correctly, in the second for would be to separate the values from the main diagonal to a second array and reset the values. And in the third will reverse the values that are in the last column of this vector.
The function arrayPosition returns the value of the array position as a function of the 2 for that simulate it as a matrix.
I’ve been using the Visual Studio 2012.
"works properly". The contents of the array is the same content as the file? You checked this?
– Guilherme Bernal
@Guilhermebernal, yes, it is correct, in the first.
– Macario1983
Why
iandjsanesharedin the last cycle?– luiscubal
@luiscubal I forgot to pack this part, because she is commented, in fact the 2 are
privates. But the mistake already begins in the secondfor– Macario1983
You can post the function
arrayPositionand how the array was declaredvariableArray?– user5299
@Tomásbadan posted the entire code!
– Macario1983