38 lines
704 B
C++
38 lines
704 B
C++
#include "nr.h"
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extern Vec_DP *x_p;
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extern Mat_DP *d_p;
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void NR::pzextr(const int iest, const DP xest, Vec_I_DP &yest, Vec_O_DP &yz,
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Vec_O_DP &dy)
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{
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int j,k1;
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DP q,f2,f1,delta;
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int nv=yz.size();
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Vec_DP c(nv);
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Vec_DP &x=*x_p;
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Mat_DP &d=*d_p;
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x[iest]=xest;
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for (j=0;j<nv;j++) dy[j]=yz[j]=yest[j];
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if (iest == 0) {
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for (j=0;j<nv;j++) d[j][0]=yest[j];
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} else {
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for (j=0;j<nv;j++) c[j]=yest[j];
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for (k1=0;k1<iest;k1++) {
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delta=1.0/(x[iest-k1-1]-xest);
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f1=xest*delta;
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f2=x[iest-k1-1]*delta;
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for (j=0;j<nv;j++) {
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q=d[j][k1];
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d[j][k1]=dy[j];
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delta=c[j]-q;
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dy[j]=f1*delta;
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c[j]=f2*delta;
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yz[j] += dy[j];
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}
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}
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for (j=0;j<nv;j++) d[j][iest]=dy[j];
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}
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}
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