[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Bug-gsl] bug in gsl_linalg_QRPT_decomp2 ?
From: |
Mario Pernici |
Subject: |
[Bug-gsl] bug in gsl_linalg_QRPT_decomp2 ? |
Date: |
Fri, 25 Apr 2003 18:51:29 +0200 (CEST) |
gsl version: 1.3
Red Hat 7.3
gcc version 2.96
Dear Sirs,
from the documentation I understand that
the norms of each column of R are stored in the vector norm.
However from the following example it seems that in the vector norm
are stored the absolute values of the diagonal elements of R.
Best Regards
Mario Pernici
===========================
#include <stdio.h>
#include <gsl/gsl_linalg.h>
int main() {
double a_data[] = {1,2,3, 1,5,6, 1,8,9, 1,11,12};
gsl_matrix_view m = gsl_matrix_view_array(a_data, 4, 3);
gsl_matrix *q, *r;
gsl_vector *tau, *norm;
int signum, i,j;
gsl_permutation * p = gsl_permutation_alloc (3);
q = gsl_matrix_alloc(4,4);
r = gsl_matrix_alloc(4,3);
tau = gsl_vector_alloc(3);
norm = gsl_vector_alloc(3);
gsl_linalg_QRPT_decomp2(&m.matrix, q, r, tau, p, &signum, norm);
for(i=0; i < 3; i++) {
printf("%lf\t", gsl_vector_get(norm, i));
}
puts("\n");
for(i=0; i < 4; i++) {
for(j=0; j <3; j++) {
printf("%lf \t", gsl_matrix_get(r,i,j));
}
printf("\n");
}
}
================================
Output:
16.431677 0.816497 0.000000
-16.431677 -1.825742 -14.605935
0.000000 -0.816497 0.816497
0.000000 0.000000 0.000000
0.000000 0.000000 0.000000
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Bug-gsl] bug in gsl_linalg_QRPT_decomp2 ?,
Mario Pernici <=