#include <math.h>#define MAXITS 1000#define EPS 1.0e-5void sor(double **a, double **b, double **c, double **d, double **e,	double **f, double **u, int jmax, double rjac){	void nrerror(char error_text[]);	int ipass,j,jsw,l,lsw,n;	double anorm,anormf=0.0,omega=1.0,resid;	for (j=2;j<jmax;j++)		for (l=2;l<jmax;l++)			anormf += fabs(f[j][l]);	for (n=1;n<=MAXITS;n++) {		anorm=0.0;		jsw=1;		for (ipass=1;ipass<=2;ipass++) {			lsw=jsw;			for (j=2;j<jmax;j++) {				for (l=lsw+1;l<jmax;l+=2) {					resid=a[j][l]*u[j+1][l]						+b[j][l]*u[j-1][l]						+c[j][l]*u[j][l+1]						+d[j][l]*u[j][l-1]						+e[j][l]*u[j][l]						-f[j][l];					anorm += fabs(resid);					u[j][l] -= omega*resid/e[j][l];				}				lsw=3-lsw;			}			jsw=3-jsw;			omega=(n == 1 && ipass == 1 ? 1.0/(1.0-0.5*rjac*rjac) :				1.0/(1.0-0.25*rjac*rjac*omega));		}		if (anorm < EPS*anormf) return;	}	nrerror("MAXITS exceeded");}#undef MAXITS#undef EPS