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2025-02-Numerical/lib/nr/cpp/recipes/pinvs.cpp
2025-09-12 18:55:25 +09:00

66 lines
1.4 KiB
C++

#include <cmath>
#include "nr.h"
using namespace std;
void NR::pinvs(const int ie1, const int ie2, const int je1, const int jsf,
const int jc1, const int k, Mat3D_O_DP &c, Mat_IO_DP &s)
{
int jpiv,jp,je2,jcoff,j,irow,ipiv,id,icoff,i;
DP pivinv,piv,dum,big;
const int iesize=ie2-ie1;
Vec_INT indxr(iesize);
Vec_DP pscl(iesize);
je2=je1+iesize;
for (i=ie1;i<ie2;i++) {
big=0.0;
for (j=je1;j<je2;j++)
if (fabs(s[i][j]) > big) big=fabs(s[i][j]);
if (big == 0.0)
nrerror("Singular matrix - row all 0, in pinvs");
pscl[i-ie1]=1.0/big;
indxr[i-ie1]=0;
}
for (id=0;id<iesize;id++) {
piv=0.0;
for (i=ie1;i<ie2;i++) {
if (indxr[i-ie1] == 0) {
big=0.0;
for (j=je1;j<je2;j++) {
if (fabs(s[i][j]) > big) {
jp=j;
big=fabs(s[i][j]);
}
}
if (big*pscl[i-ie1] > piv) {
ipiv=i;
jpiv=jp;
piv=big*pscl[i-ie1];
}
}
}
if (s[ipiv][jpiv] == 0.0)
nrerror("Singular matrix in routine pinvs");
indxr[ipiv-ie1]=jpiv+1;
pivinv=1.0/s[ipiv][jpiv];
for (j=je1;j<=jsf;j++) s[ipiv][j] *= pivinv;
s[ipiv][jpiv]=1.0;
for (i=ie1;i<ie2;i++) {
if (indxr[i-ie1] != jpiv+1) {
if (s[i][jpiv] != 0.0) {
dum=s[i][jpiv];
for (j=je1;j<=jsf;j++)
s[i][j] -= dum*s[ipiv][j];
s[i][jpiv]=0.0;
}
}
}
}
jcoff=jc1-je2;
icoff=ie1-je1;
for (i=ie1;i<ie2;i++) {
irow=indxr[i-ie1]+icoff;
for (j=je2;j<=jsf;j++) c[irow-1][j+jcoff][k]=s[i][j];
}
}