36 lines
585 B
C++
36 lines
585 B
C++
#include <cmath>
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#include "nr.h"
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using namespace std;
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void NR::elmhes(Mat_IO_DP &a)
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{
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int i,j,m;
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DP y,x;
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int n=a.nrows();
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for (m=1;m<n-1;m++) {
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x=0.0;
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i=m;
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for (j=m;j<n;j++) {
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if (fabs(a[j][m-1]) > fabs(x)) {
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x=a[j][m-1];
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i=j;
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}
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}
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if (i != m) {
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for (j=m-1;j<n;j++) SWAP(a[i][j],a[m][j]);
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for (j=0;j<n;j++) SWAP(a[j][i],a[j][m]);
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}
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if (x != 0.0) {
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for (i=m+1;i<n;i++) {
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if ((y=a[i][m-1]) != 0.0) {
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y /= x;
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a[i][m-1]=y;
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for (j=m;j<n;j++) a[i][j] -= y*a[m][j];
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for (j=0;j<n;j++) a[j][m] += y*a[j][i];
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}
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}
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}
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}
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}
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