mpi-cos(x) 的积分

 实现代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "mpi.h"
#define PI 3.141593
int main(int argc,char** argv){
	int rank,size;
	double a,b;
	a=0;
	b=PI/2;
	int p=size-1;
	int n=10;
	double h;
	h=(b-a)/p/n;
	
	MPI_Comm comm= MPI_COMM_WORLD;
	MPI_Status status;
	MPI_Init(&argc,&argv);
	MPI_Comm_size(comm,&size);
	MPI_Comm_rank(comm,&rank);

	if(rank== size-1){
		int j=0;
		double fin=0;
		double tem;
		for(j=0;j<size-1;j++){
			MPI_Recv(&tem,1,MPI_DOUBLE,j,99,comm,MPI_STATUS_IGNORE);
			fin=fin+tem;
			//printf("%d:%lf.\n",j,tem);
		}
		printf("cos(%f,%f):%f\n",a,b,fin);
	}
	else{
		int j=0;
		double part=0;
		for(j=0;j<n;j++){
			part= part+ cos(a+(rank*n+j)*h+h/2)*h;
		}
		MPI_Send(&part,1,MPI_DOUBLE,size-1,99,comm);
	}
	MPI_Finalize();
	return 0;
} 

结果截图：