32 lines
481 B
C++
32 lines
481 B
C++
#include "nr.h"
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void NR::vander(Vec_I_DP &x, Vec_O_DP &w, Vec_I_DP &q)
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{
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int i,j,k;
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DP b,s,t,xx;
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int n=q.size();
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Vec_DP c(n);
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if (n == 1) w[0]=q[0];
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else {
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for (i=0;i<n;i++) c[i]=0.0;
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c[n-1] = -x[0];
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for (i=1;i<n;i++) {
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xx = -x[i];
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for (j=(n-1-i);j<(n-1);j++) c[j] += xx*c[j+1];
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c[n-1] += xx;
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}
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for (i=0;i<n;i++) {
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xx=x[i];
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t=b=1.0;
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s=q[n-1];
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for (k=n-1;k>0;k--) {
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b=c[k]+xx*b;
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s += q[k-1]*b;
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t=xx*t+b;
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}
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w[i]=s/t;
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}
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}
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}
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