47 lines
998 B
C
47 lines
998 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 ITMAX 20
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#define TINY 1.0e-6
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void qroot(float p[], int n, float *b, float *c, float eps)
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{
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void poldiv(float u[], int n, float v[], int nv, float q[], float r[]);
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int iter;
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float sc,sb,s,rc,rb,r,dv,delc,delb;
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float *q,*qq,*rem;
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float d[3];
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q=vector(0,n);
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qq=vector(0,n);
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rem=vector(0,n);
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d[2]=1.0;
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for (iter=1;iter<=ITMAX;iter++) {
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d[1]=(*b);
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d[0]=(*c);
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poldiv(p,n,d,2,q,rem);
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s=rem[0];
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r=rem[1];
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poldiv(q,(n-1),d,2,qq,rem);
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sb = -(*c)*(rc = -rem[1]);
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rb = -(*b)*rc+(sc = -rem[0]);
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dv=1.0/(sb*rc-sc*rb);
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delb=(r*sc-s*rc)*dv;
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delc=(-r*sb+s*rb)*dv;
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*b += (delb=(r*sc-s*rc)*dv);
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*c += (delc=(-r*sb+s*rb)*dv);
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if ((fabs(delb) <= eps*fabs(*b) || fabs(*b) < TINY)
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&& (fabs(delc) <= eps*fabs(*c) || fabs(*c) < TINY)) {
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free_vector(rem,0,n);
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free_vector(qq,0,n);
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free_vector(q,0,n);
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return;
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}
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}
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nrerror("Too many iterations in routine qroot");
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}
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#undef ITMAX
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#undef TINY
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#undef NRANSI
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