Re: [Getfem-users] gesvd_interface

[Yves Renard]

Dear Philipp Lamby,

I agree with this. I will correct it. Thank you for the bug report.

Yves.



Le 13/02/2013 20:17, Philipp Lamby a écrit :
> Hello, 
>
> I have got a question concerning lines 379 and 399 in 
> gmm/gmm_lapack_interface.h:
>     
>    resize(U, m, n);     /* Why not resize(U, m, m); ? */ 
>
> I think, in the SVD  X = U*S*V^T, the orthogonal Matrix U should have 
> dimensions mxm.
> After reading the LAPACK documentation, I do not see a reason why U should 
> have n 
> columns. Actually I think, if X is overdetermined (m>n) the current code 
> might cause 
> memory violations when calling the interfaced LAPACK routine. In my 
> application X 
> is underdetermined, and I stumbled later in my code, because I unexpectedly 
> could 
> not  multiply U^T with a vector of length m.  
>
> Best regards, 
>   Philipp Lamby
>
>
> _______________________________________________
> Getfem-users mailing list
> address@hidden
> https://mail.gna.org/listinfo/getfem-users


-- 

  Yves Renard (address@hidden)       tel : (33) 04.72.43.87.08
  Pole de Mathematiques, INSA-Lyon             fax : (33) 04.72.43.85.29
  20, rue Albert Einstein
  69621 Villeurbanne Cedex, FRANCE
  http://math.univ-lyon1.fr/~renard

---------