[Help-gsl] newbie eigenvalues

[Fabrizio Laurini]

Dear all,

I've successfully installed gsl on my Fedora 5 system. I'm playing with 
some examples on eigenvalues (using the example given in the manual) and 
I found something quite strange when computing eigenvalues of a simple 
squared matrix of order 2, whose values are taken from the array

double data[] = {1.511867, 0, 5.744244, 0};

Thus, the matrix has the second column with two zeros. I'm expecting to 
see 1 eigenvalue equal to zero and the second equal to 1.511867, while, 
after compiling and following the same structure of the example code, I got

$./a.out
eigenvalue = -5.03784
eigenvector =
-0.659366
0.751822
eigenvalue = 6.5497
eigenvector =
0.751822
0.659366

Notice that using the array of the example code

double data[] = { 1.0 , 1/2.0, 1/3.0, 1/4.0,
1/2.0, 1/3.0, 1/4.0, 1/5.0,
1/3.0, 1/4.0, 1/5.0, 1/6.0,
1/4.0, 1/5.0, 1/6.0, 1/7.0 };


I got exactly what is in the manual, i.e.

$ ./a.out
eigenvalue = 9.67023e-05
eigenvector =
-0.0291933
0.328712
-0.791411
0.514553

Am I missing something?

Thanks and regards,

Fabrizio


--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.394 / Virus Database: 268.9.5/377 - Release Date: 27/06/2006