73 lines
1.6 KiB
C
73 lines
1.6 KiB
C
#include <math.h>
|
|
#include <string.h>
|
|
#include "timer.h"
|
|
|
|
#define NN 1024
|
|
#define NM 1024
|
|
|
|
float A[NN][NM];
|
|
float Anew[NN][NM];
|
|
|
|
int main(int argc, char** argv)
|
|
{
|
|
const int n = NN;
|
|
const int m = NM;
|
|
const int iter_max = 1000;
|
|
|
|
const double tol = 1.0e-6;
|
|
double error = 1.0;
|
|
|
|
memset(A, 0, n * m * sizeof(float));
|
|
memset(Anew, 0, n * m * sizeof(float));
|
|
|
|
for (int j = 0; j < n; j++)
|
|
{
|
|
A[j][0] = 1.0;
|
|
Anew[j][0] = 1.0;
|
|
}
|
|
|
|
printf("Jacobi relaxation Calculation: %d x %d mesh\n", n, m);
|
|
|
|
StartTimer();
|
|
int iter = 0;
|
|
|
|
while ( error > tol && iter < iter_max )
|
|
{
|
|
#pragma acc kernels
|
|
{
|
|
error = 0.0;
|
|
|
|
#pragma omp parallel for shared(m, n, Anew, A)
|
|
for( int j = 1; j < n-1; j++)
|
|
{
|
|
for( int i = 1; i < m-1; i++ )
|
|
{
|
|
Anew[j][i] = 0.25 * ( A[j][i+1] + A[j][i-1]
|
|
+ A[j-1][i] + A[j+1][i]);
|
|
error = fmax( error, fabs(Anew[j][i] - A[j][i]));
|
|
}
|
|
}
|
|
|
|
#pragma omp parallel for shared(m, n, Anew, A)
|
|
for( int j = 1; j < n-1; j++)
|
|
{
|
|
for( int i = 1; i < m-1; i++ )
|
|
{
|
|
A[j][i] = Anew[j][i];
|
|
}
|
|
}
|
|
}
|
|
|
|
if(iter % 100 == 0) printf("%5d, %0.6f\n", iter, error);
|
|
|
|
iter++;
|
|
|
|
}
|
|
|
|
double runtime = GetTimer();
|
|
|
|
printf(" total: %f s\n", runtime / 1000);
|
|
|
|
return 0;
|
|
}
|