* Problem with matrices bigger than 2x2 using gsl_linalg_LU_invert
@ 2002-08-19 3:42 Philippe Huber
2002-08-19 11:32 ` Brian Gough
0 siblings, 1 reply; 3+ messages in thread
From: Philippe Huber @ 2002-08-19 3:42 UTC (permalink / raw)
To: gsl-discuss
Hi all,
First of all, thank you for having created such a great library. I have
a small problem with gsl_linalg_LU_invert. I am using a 4x4 matrix which
is not singular. I made a LU decomposition using gsl_linalg_LU_decomp.
Then, I send it to gsl_linalg_LU_invert and it crashes. I tried with a
2x2 matrix and it works perfectly well. When debugging, I saw that at
the third iteration (i=2) of
for (i = 0; i < n; i++)
{
gsl_vector_view c = gsl_matrix_column (inverse, i);
int status_i = gsl_linalg_LU_svx (LU, p, &(c.vector));
if (status_i)
status = status_i;
}
inside decomp, c.vector.size=4 but, in invert, the side of x (which
should be c.vector.size) is 1239492! I verified that the program also
crashes with a 3x3 matrix. Is it a bug or did I make something wrong.
Please apologize if I don't send my code, it is well too big.
Thank you
Philippe
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Problem with matrices bigger than 2x2 using gsl_linalg_LU_invert
2002-08-19 3:42 Problem with matrices bigger than 2x2 using gsl_linalg_LU_invert Philippe Huber
@ 2002-08-19 11:32 ` Brian Gough
2002-08-19 12:39 ` RE : " Philippe Huber
0 siblings, 1 reply; 3+ messages in thread
From: Brian Gough @ 2002-08-19 11:32 UTC (permalink / raw)
To: Philippe Huber; +Cc: gsl-discuss
Philippe Huber writes:
> First of all, thank you for having created such a great library. I have
> a small problem with gsl_linalg_LU_invert. I am using a 4x4 matrix which
> is not singular. I made a LU decomposition using gsl_linalg_LU_decomp.
> Then, I send it to gsl_linalg_LU_invert and it crashes. I tried with a
> 2x2 matrix and it works perfectly well. I verified that the program also
> crashes with a 3x3 matrix. Is it a bug or did I make something wrong.
> Please apologize if I don't send my code, it is well too big.
Please send a small example which reproduces the bug, with details of
your operating system, compiler, etc.
regards
Brian Gough
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE : Problem with matrices bigger than 2x2 using gsl_linalg_LU_invert
2002-08-19 11:32 ` Brian Gough
@ 2002-08-19 12:39 ` Philippe Huber
0 siblings, 0 replies; 3+ messages in thread
From: Philippe Huber @ 2002-08-19 12:39 UTC (permalink / raw)
To: gsl-discuss
Dear Brian,
I found the error: I had not included two gsl source files into my
project: rowcol.c and view.c which contain functions called in
gsl_linalg_LU_invert. As a reminder, to make gsl work with Borland
Builder C++, it is necessary to include the source codes in the project.
The libraries (even the bcc ones) contain errors like bad entry points.
Thank you
Phil
-----Message d'origine-----
De : Brian Gough [mailto:bjg@network-theory.co.uk]
Envoyé : lundi, 19. août 2002 20:32
À : Philippe Huber
Cc : gsl-discuss@sources.redhat.com
Objet : Re: Problem with matrices bigger than 2x2 using
gsl_linalg_LU_invert
Philippe Huber writes:
> First of all, thank you for having created such a great library. I
have
> a small problem with gsl_linalg_LU_invert. I am using a 4x4 matrix
which
> is not singular. I made a LU decomposition using
gsl_linalg_LU_decomp.
> Then, I send it to gsl_linalg_LU_invert and it crashes. I tried with
a
> 2x2 matrix and it works perfectly well. I verified that the program
also
> crashes with a 3x3 matrix. Is it a bug or did I make something wrong.
> Please apologize if I don't send my code, it is well too big.
Please send a small example which reproduces the bug, with details of
your operating system, compiler, etc.
regards
Brian Gough
^ permalink raw reply [flat|nested] 3+ messages in thread
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2002-08-19 3:42 Problem with matrices bigger than 2x2 using gsl_linalg_LU_invert Philippe Huber
2002-08-19 11:32 ` Brian Gough
2002-08-19 12:39 ` RE : " Philippe Huber
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