36 lines
536 B
C
36 lines
536 B
C
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#define NRANSI
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#include "nrutil.h"
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void vander(double x[], double w[], double q[], int n)
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{
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int i,j,k;
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double b,s,t,xx;
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double *c;
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c=dvector(1,n);
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if (n == 1) w[1]=q[1];
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else {
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for (i=1;i<=n;i++) c[i]=0.0;
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c[n] = -x[1];
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for (i=2;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] += xx;
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}
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for (i=1;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];
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for (k=n;k>=2;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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free_dvector(c,1,n);
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}
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#undef NRANSI
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