teste04_wtime

Esta é uma pré-visualização de arquivo. Entre para ver o arquivo original

# include "mpi.h"
# include <math.h>
int main(argc, argv)
	int argc;
	char *argv[];
{
	int n, myid, numprocs, i;
	double mypi, pi, h, x, sum = 0.0;
 double MPI_Wtime(), starttime, endtime;
 
	MPI_Init(&argc, &argv);
	MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
	MPI_Comm_rank(MPI_COMM_WORLD, &myid);
	/* Cálculo de Pi */
	if ( myid == 0 ){
		printf("Entre com o numero de intervalos :");
		scanf("%d", &n);
	}
	MPI_Bcast(&n, 1, MPI_INT, 0, MPI_COMM_WORLD);
 starttime = MPI_Wtime();
	if ( n != 0 ){
		h = 1.0/(double)n;
		for ( i = myid + 1; i <= n; i += numprocs ){
			x = h * ((double)i - 0.5 );
			sum += (4.0/(1.0 + x*x));
		}
	}
	/* Fim cálculo Pi */
	mypi = h * sum;
	MPI_Reduce(&mypi, &pi, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
 endtime = MPI_Wtime();
	if ( myid == 0 ){
		printf("Valor aproximado de Pi: %.16f\n tempo: %.16f\n", pi,endtime-starttime);
	}
	
MPI_Finalize();
}