Tambahin file scatter gatter dari praktikum 1

bucketsort.c

+// Copyright 2012 www.mpitutorial.com 
+ 
+//  Program yang menghitung rata rata dari array secara paralel menggunakan scatter dan gather
+#include <stdio.h> 
+#include <stdlib.h> 
+#include <time.h> 
+#include <mpi.h> 
+#include <assert.h> 
+ 
+float *create_rand_nums(int num_elements) { 
+	float *rand_nums = (float *)malloc(sizeof(float) * num_elements); 
+	assert(rand_nums != NULL); 
+	int i; 
+	for (i = 0; i < num_elements; i++) { 
+		rand_nums[i] = (rand() / (float)RAND_MAX); 
+	} 
+	return rand_nums; 
+} 
+ 
+float compute_avg(float *array, int num_elements) { 
+	float sum = 0.f; 
+	int i; 
+	for (i = 0; i < num_elements; i++) { 
+		sum += array[i]; 
+	} 
+	return sum / num_elements; 
+} 
+ 
+int main(int argc, char** argv) { 
+	if (argc != 2) { 
+		fprintf(stderr, "Usage: avg num_elements_per_proc\n"); 
+		exit(1); 
+	} 
+	 
+	int num_elements_per_proc = atoi(argv[1]); 
+	srand(time(NULL)); 
+	 
+	MPI_Init(NULL, NULL); 
+	 
+	int world_rank; 
+	MPI_Comm_rank(MPI_COMM_WORLD, &world_rank); 
+	int world_size; 
+	MPI_Comm_size(MPI_COMM_WORLD, &world_size); 
+	 
+	float *rand_nums = NULL; 
+	if (world_rank == 0) { 
+		rand_nums = create_rand_nums(num_elements_per_proc * world_size); 
+	} 
+	 
+	float *sub_rand_nums = (float *)malloc(sizeof(float) * 
+	num_elements_per_proc); 
+	assert(sub_rand_nums != NULL); 
+	 
+	MPI_Scatter(rand_nums, num_elements_per_proc, MPI_FLOAT, sub_rand_nums, 
+	num_elements_per_proc, MPI_FLOAT, 0, MPI_COMM_WORLD); 
+	 
+	float sub_avg = compute_avg(sub_rand_nums, num_elements_per_proc); 
+	 
+	float *sub_avgs = NULL; 
+	if (world_rank == 0) { 
+		sub_avgs = (float *)malloc(sizeof(float) * world_size); 
+		assert(sub_avgs != NULL); 
+	} 
+	MPI_Gather(&sub_avg, 1, MPI_FLOAT, sub_avgs, 1, MPI_FLOAT, 0, 
+	MPI_COMM_WORLD); 
+	 
+	if (world_rank == 0) { 
+		float avg = compute_avg(sub_avgs, world_size); 
+		printf("Avg of all elements is %f\n", avg); 
+	} 
+	 
+	if (world_rank == 0) { 
+		free(rand_nums); 
+		free(sub_avgs); 
+	} 
+	free(sub_rand_nums); 
+	 
+	MPI_Barrier(MPI_COMM_WORLD); 
+	MPI_Finalize(); 
+}  
+
+

mpi_hostfile

+#daftar_host
+localhost
+167.205.35.26
+167.205.35.28
+167.205.35.29
+167.205.35.30
+167.205.35.31
+#167.205.35.32
+#167.205.35.33
+#167.205.35.34
+