[Numpy-discussion] linalg.svd not working?

Muhammad Alkarouri malkarouri@yahoo.co...
Fri May 8 08:33:46 CDT 2009

Replying to myself, just that the experience may benefit a later user.

--- On Wed, 6/5/09, Muhammad Alkarouri <malkarouri@yahoo.co.uk> wrote:

> From: Muhammad Alkarouri <malkarouri@yahoo.co.uk>
> Subject: Re: [Numpy-discussion] linalg.svd not working?
> It is an atlas problem. Not that I knew how to correct it,
> but I was able to build numpy with a standard package blas
> and lapack, and the tests passed without incident.

After installing numpy using the standard blas/lapack on red hat enterprise 4, the tests succeeded. Scipy was then compiled and installed, but it failed its test. Specifically, some tests failed with "undefined symbolr: srotmg_".
This means that the standard blas library is not complete according to past emails, so I had to go back and try installing Atlas.

It turns out that for the compilers I am using (gcc, g77 3.4.4) lapack and atlas must be compiled with the option "-ffloat-store" (https://bugzilla.redhat.com/show_bug.cgi?id=138683) so after doing that, recompiling and installing numpy, numpy tests succeeded (again).
The last problem was when installing scipy, I had a series of errors "NoneType object is not callable", and errors with calc_lwork. Turns out they are from a library flinalg. The solution is to compile scipy with the option: python setup.py build_ext -DUNDERSCORE_G77. Probably the reason for the last group of problems would be that scipy used gfortran in some place and that the correct action was to force the g77 compiler, but I didn't check. Anyway, the numpy and scipy tests succeeded after that.

For all this installation I used CC='gcc -m32 -ffloat-store' and F77FLAGS='-m32' to get 32 bit installation on an x86_64 machine. Changing most of the other flags will mess up numpy and/or scipy installation.

Many thanks,

Muhammad Alkarouri


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