#define NRANSI#include "nrutil.h"#define NPRE 1#define NPOST 1#define NGMAX 15void mglin(double **u, int n, int ncycle){	void addint(double **uf, double **uc, double **res, int nf);	void copy(double **aout, double **ain, int n);	void fill0(double **u, int n);	void interp(double **uf, double **uc, int nf);	void relax(double **u, double **rhs, int n);	void resid(double **res, double **u, double **rhs, int n);	void rstrct(double **uc, double **uf, int nc);	void slvsml(double **u, double **rhs);	unsigned int j,jcycle,jj,jpost,jpre,nf,ng=0,ngrid,nn;	double **ires[NGMAX+1],**irho[NGMAX+1],**irhs[NGMAX+1],**iu[NGMAX+1];	nn=n;	while (nn >>= 1) ng++;	if (n != 1+(1L << ng)) nrerror("n-1 must be a power of 2 in mglin.");	if (ng > NGMAX) nrerror("increase NGMAX in mglin.");	nn=n/2+1;	ngrid=ng-1;	irho[ngrid]=dmatrix(1,nn,1,nn);	rstrct(irho[ngrid],u,nn);	while (nn > 3) {		nn=nn/2+1;		irho[--ngrid]=dmatrix(1,nn,1,nn);		rstrct(irho[ngrid],irho[ngrid+1],nn);	}	nn=3;	iu[1]=dmatrix(1,nn,1,nn);	irhs[1]=dmatrix(1,nn,1,nn);	slvsml(iu[1],irho[1]);	free_dmatrix(irho[1],1,nn,1,nn);	ngrid=ng;	for (j=2;j<=ngrid;j++) {		nn=2*nn-1;		iu[j]=dmatrix(1,nn,1,nn);		irhs[j]=dmatrix(1,nn,1,nn);		ires[j]=dmatrix(1,nn,1,nn);		interp(iu[j],iu[j-1],nn);		copy(irhs[j],(j != ngrid ? irho[j] : u),nn);		for (jcycle=1;jcycle<=ncycle;jcycle++) {			nf=nn;			for (jj=j;jj>=2;jj--) {			for (jpre=1;jpre<=NPRE;jpre++)				relax(iu[jj],irhs[jj],nf);			resid(ires[jj],iu[jj],irhs[jj],nf);			nf=nf/2+1;			rstrct(irhs[jj-1],ires[jj],nf);			fill0(iu[jj-1],nf);			}			slvsml(iu[1],irhs[1]);			nf=3;			for (jj=2;jj<=j;jj++) {			nf=2*nf-1;			addint(iu[jj],iu[jj-1],ires[jj],nf);			for (jpost=1;jpost<=NPOST;jpost++)				relax(iu[jj],irhs[jj],nf);			}		}	}	copy(u,iu[ngrid],n);	for (nn=n,j=ng;j>=2;j--,nn=nn/2+1) {		free_dmatrix(ires[j],1,nn,1,nn);		free_dmatrix(irhs[j],1,nn,1,nn);		free_dmatrix(iu[j],1,nn,1,nn);		if (j != ng) free_dmatrix(irho[j],1,nn,1,nn);	}	free_dmatrix(irhs[1],1,3,1,3);	free_dmatrix(iu[1],1,3,1,3);}#undef NPRE#undef NPOST#undef NGMAX#undef NRANSI