Geografic-Information-System/lib/vector/transform/m_mult.c

/*  @(#)m_mult.c        2.1  6/26/87  */
#include <stdio.h>
#include <grass/libtrans.h>

#define		N	3

/*
 * m_mult: matrix multiplication (return c = a * b)
 *  3x3 matric by 3x1 matric
 */

int m_mult(double a[N][N], double b[N], double c[N])
{
    register int i, j;

    for (i = 0; i < N; i++) {
	c[i] = 0.0;

	for (j = 0; j < N; j++)
	    c[i] += (a[i][j] * b[j]);
    }

    return 1;
}