37 lines
587 B
C
37 lines
587 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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void rotate(float **r, float **qt, int n, int i, float a, float b)
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{
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int j;
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float c,fact,s,w,y;
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if (a == 0.0) {
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c=0.0;
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s=(b >= 0.0 ? 1.0 : -1.0);
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} else if (fabs(a) > fabs(b)) {
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fact=b/a;
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c=SIGN(1.0/sqrt(1.0+(fact*fact)),a);
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s=fact*c;
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} else {
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fact=a/b;
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s=SIGN(1.0/sqrt(1.0+(fact*fact)),b);
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c=fact*s;
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}
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for (j=i;j<=n;j++) {
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y=r[i][j];
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w=r[i+1][j];
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r[i][j]=c*y-s*w;
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r[i+1][j]=s*y+c*w;
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}
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for (j=1;j<=n;j++) {
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y=qt[i][j];
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w=qt[i+1][j];
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qt[i][j]=c*y-s*w;
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qt[i+1][j]=s*y+c*w;
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}
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}
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#undef NRANSI
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