28 lines
460 B
C
28 lines
460 B
C
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#include <math.h>
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#define NRANSI
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#include "nrutil.h"
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#define EPS 1.0e-4
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void fdjac(int n, float x[], float fvec[], float **df,
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void (*vecfunc)(int, float [], float []))
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{
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int i,j;
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float h,temp,*f;
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f=vector(1,n);
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for (j=1;j<=n;j++) {
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temp=x[j];
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h=EPS*fabs(temp);
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if (h == 0.0) h=EPS;
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x[j]=temp+h;
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h=x[j]-temp;
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(*vecfunc)(n,x,f);
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x[j]=temp;
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for (i=1;i<=n;i++) df[i][j]=(f[i]-fvec[i])/h;
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}
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free_vector(f,1,n);
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}
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#undef EPS
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#undef NRANSI
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