Multiplication

Matrix-Vector Multiplication MPI C Source Code

Here’s my first task for MPI Programming. Create a matrix-vector multiplication program using Message Passing Interface. Let’s go directly to the source code and we can discuss it later if you want.

First, MPI with C language commonly use “mpi.h” and you still can use standard C library.

#include "stdio.h"
#include "stdlib.h"
#include "time.h"
#include "math.h"

#include "mpi.h"

Now, we need to define the size of matrices, A as [AROW x ACOL] and B as [ACOL x 1] so the result let’s call it matrix C [AROW x 1]. Because the row of B must be equals with column of A and the result matrix C has row = AROW and single column. MAX_VALUE is the constant for defining maximum value of random number for matrices elements value.

#define AROW 3
#define ACOL 2

#define MAX_VALUE 10

proc_map() function is the function to map the each task to which process to do it.


/* Process mapping function */
int proc_map(int i, int size)
{
	size = size - 1;
	int r = (int) ceil( (double)AROW / (double)size);
	int proc = i / r;
	return proc + 1;
}

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