27 lines
506 B
C
27 lines
506 B
C
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#include <math.h>
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#define EPS 1.0e-6
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#define JMAX 20
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float qsimp(float (*func)(float), float a, float b)
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{
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float trapzd(float (*func)(float), float a, float b, int n);
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void nrerror(char error_text[]);
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int j;
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float s,st,ost=0.0,os=0.0;
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for (j=1;j<=JMAX;j++) {
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st=trapzd(func,a,b,j);
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s=(4.0*st-ost)/3.0;
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if (j > 5)
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if (fabs(s-os) < EPS*fabs(os) ||
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(s == 0.0 && os == 0.0)) return s;
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os=s;
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ost=st;
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}
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nrerror("Too many steps in routine qsimp");
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return 0.0;
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}
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#undef EPS
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#undef JMAX
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