SOR.c

#include "SOR.h"

double SOR_num_flops(int M, int N, int num_iterations) {
	double Md = (double) M;
	double Nd = (double) N;
	double num_iterD = (double) num_iterations;

	return (Md-1)*(Nd-1)*num_iterD*6.0;
}

void SOR_execute(int M,
                 int N,
                 double omega,
                 double** G,
                 int num_iterations) {
	double omega_over_four = omega * 0.25;
	double one_minus_omega = 1.0 - omega;

	/* update interior points */

	int Mm1 = M - 1;
	int Nm1 = N - 1;
	int p;
	int i;
	int j;
	double* Gi;
	double* Gim1;
	double* Gip1;

	for (p = 0; p < num_iterations; p++) {
		for (i = 1; i < Mm1; i++) {
			Gi = G[i];
			Gim1 = G[i - 1];
			Gip1 = G[i + 1];
			for (j = 1; j < Nm1; j++)
				Gi[j] = omega_over_four * (Gim1[j] + Gip1[j] + Gi[j - 1] + Gi[j + 1]) +
				        one_minus_omega * Gi[j];
		}
	}
}