RE: [Lapackpp-devel] LaSVD_IP() Error for only 'sigma' matrix

[Jacob \(Jack\) G. <jg...@cs...>]

Hi,

At the time I wrote the e-mail, I didn't have the error output infront of
me, so I was only trying to get it from memory.  The error was actually as
follows:

** On entry to DGESDD parameter number  8 had an illegal value

Jack

-----Original Message-----
From: Christian Stimming [mailto:sti...@tu...] 
Sent: Sunday, December 19, 2004 8:39 AM
To: Jacob (Jack) Gryn; lap...@li...
Subject: Re: [Lapackpp-devel] LaSVD_IP() Error for only 'sigma' matrix

Am Sonntag, 19. Dezember 2004 00:59 schrieb Jacob (Jack) Gryn:
> The function:
>
> void LaSVD_IP(LaGenMatDouble& A, LaVectorDouble &Sigma);
>
> When run on a 3x3 matrix, doesn't seem to work, it gives some sort of
error
> about parameter 7 to the lapack call has an invalid parameter.  (Probably
> lwork again).  For now, I'm just using the call that stores U, Sigma and
> VT.

The parameter 7 is &U(0,0), i.e. the pointer to the temporary U. I thought 
that one will not be referenced at all. Nevertheless, there might be an
error 
if U is defined with 0x0 dimension, so that accessing the first element
gives 
some weird results.

I just changed the code in CVS so that the temporary U and VT have dimension

1x1, so that U(0,0) will return the reference to a valid memory location. 
Hopefully that should fix it.

Christian