37 lines
602 B
C++
37 lines
602 B
C++
#include <cmath>
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#include "nr.h"
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using namespace std;
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void NR::rotate(Mat_IO_DP &r, Mat_IO_DP &qt, const int i, const DP a,
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const DP b)
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{
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int j;
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DP c,fact,s,w,y;
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int n=r.nrows();
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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=0;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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