From: Nuralanur@...
Date: 2006-08-01T03:09:27+09:00
Subject: Re: Setting precision in Ruby-GSL calculations ?

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Dear Ed, dear Yoshiki,
 
thanks for your replies.. I am now able to reproduce your results in  
Ruby-Gsl,
(eliminating some typos),
 
and I've learnt that there are some conflicting definitions of singular  value
decompositions, which lead to part of my difficulties:
 
Ruby-Gsl defines these as  M= U S V^tr, 
where U can have uneven dimensions, but many authors require U  to
be square (and softwares, eg. Mathematica) - then it has the  dimensions
of the image space of the linear mapping M defines ... this definition  makes
it easier to calculate pseudo-inverses, as it doesn't lead to dimension  
problems
in multiplication....
 
I still don't know why I don't get singular values to higher precision  ...
does one have to convert to Float or something ? 
 
Thank you for your time,
 
Best reagrds,
 
Axel 

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