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2025-09-12 18:55:25 +09:00

40 lines
936 B
C++

#include <cmath>
#include "nr.h"
using namespace std;
void NR::sor(Mat_I_DP &a, Mat_I_DP &b, Mat_I_DP &c, Mat_I_DP &d, Mat_I_DP &e,
Mat_I_DP &f, Mat_IO_DP &u, const DP rjac)
{
const int MAXITS=1000;
const DP EPS=1.0e-13;
int j,l,n,ipass,jsw,lsw;
DP anorm,anormf=0.0,omega=1.0,resid;
int jmax=a.nrows();
for (j=1;j<jmax-1;j++)
for (l=1;l<jmax-1;l++)
anormf += fabs(f[j][l]);
for (n=0;n<MAXITS;n++) {
anorm=0.0;
jsw=1;
for (ipass=0;ipass<2;ipass++) {
lsw=jsw;
for (j=1;j<jmax-1;j++) {
for (l=lsw;l<jmax-1;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 == 0 && ipass == 0 ? 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");
}