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/* Heat equation solver in 2D. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "heat.h"
int main(int argc, char **argv)
{
double a = 0.5; //!< Diffusion constant
field current, previous; //!< Current and previous temperature fields
double dt; //!< Time step
int nsteps; //!< Number of time steps
int image_interval = 1000; //!< Image output interval
int iter; //!< Iteration counter
double dx2, dy2; //!< delta x and y squared
clock_t start_clock; //!< Time stamps
#pragma omp parallel private(iter)
{
initialize(argc, argv, ¤t, &previous, &nsteps);
#pragma omp single
{
/* Output the initial field */
write_field(¤t, 0);
/* Largest stable time step */
dx2 = current.dx * current.dx;
dy2 = current.dy * current.dy;
dt = dx2 * dy2 / (2.0 * a * (dx2 + dy2));
/* Get the start time stamp */
start_clock = clock();
}
/* Time evolve */
for (iter = 1; iter < nsteps; iter++) {
evolve(¤t, &previous, a, dt);
if (iter % image_interval == 0) {
#pragma omp single
write_field(¤t, iter);
}
/* Swap current field so that it will be used
as previous for next iteration step */
#pragma omp single
swap_fields(¤t, &previous);
}
} /* End of parallel region */
/* Determine the CPU time used for the iteration */
printf("Iteration took %.3f seconds.\n", (double)(clock() - start_clock) /
(double)CLOCKS_PER_SEC);
printf("Reference value at 5,5: %f\n", previous.data[5][5]);
finalize(¤t, &previous);
return 0;
}