Re: Slow sqp execution in Ubuntu compared to Win7?

[Carlo de Falco]

On 3 Apr 2010, at 09:44, Tottish wrote:

> Hmmm, I'm back at the computer but I can't really see where I have a  
> choice
> of which BLAS/LAPACK to use?

look at the list of the dependencies for octave3.2 here:
http://packages.ubuntu.com/karmic/math/octave3.2

as you can see there are multiple choices for the package to satisfy  
the dependency
on blas and lapack. in particular:
"libblas.so.3gf	 virtual package provided by libatlas3gf-3dnow,  
libatlas3gf-base, libatlas3gf-sse, libatlas3gf-sse2, libblas3gf"
so any of the packages above can be chosen

> I use Synaptic and seem to have the libatlas3gf-base installed (ATLAS,
> generic shared). Is this the one for me or should I install  
> something else?
> What?

this is highly dependent on your hardware, if you are not sure which  
one of the above
is more appropriate you can just do trial-and-error.


> I've made some tests and adjusted the stop criteria in sqp. When  
> it's set to
> default (eps) it only needs four iterations to hit the mark. This  
> takes, as
> I mentioned, about 0.24s where's one iteration takes 0.08, 2 iter  
> takes 0.14
> and 3 iter takes 0.19s.
> I guess this rather linear behavior points to the fact that it is  
> the actual
> calculation that takes time and not the linking, right?
> On the Sempron running Win7 the difference was not noticeable when  
> running
> the same test. It took about 0.08 no matter how many iterations.
>
> So what do you make of this? Am I stuck at the 0.24s or can I get it  
> faster?
>
> Have a good one, folks!
> /Totte
> --
> View this message in context: 
> http://n4.nabble.com/Slow-sqp-execution-in-Ubuntu-compared-to-Win7-tp1749282p1749940.html
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Begin forwarded message:

> From: Tottish <address@hidden>
> Date: 3 April 2010 09:44:41 GMT+02:00
> To: address@hidden
> Subject: Re: Slow sqp execution in Ubuntu compared to Win7?
>
>
> Hmmm, I'm back at the computer but I can't really see where I have a  
> choice
> of which BLAS/LAPACK to use?
> I use Synaptic and seem to have the libatlas3gf-base installed (ATLAS,
> generic shared). Is this the one for me or should I install  
> something else?
> What?
>
> I've made some tests and adjusted the stop criteria in sqp. When  
> it's set to
> default (eps) it only needs four iterations to hit the mark. This  
> takes, as
> I mentioned, about 0.24s where's one iteration takes 0.08, 2 iter  
> takes 0.14
> and 3 iter takes 0.19s.
> I guess this rather linear behavior points to the fact that it is  
> the actual
> calculation that takes time and not the linking, right?
> On the Sempron running Win7 the difference was not noticeable when  
> running
> the same test. It took about 0.08 no matter how many iterations.
>
> So what do you make of this? Am I stuck at the 0.24s or can I get it  
> faster?
>
> Have a good one, folks!
> /Totte
> --
> View this message in context: 
> http://n4.nabble.com/Slow-sqp-execution-in-Ubuntu-compared-to-Win7-tp1749282p1749940.html
> Sent from the Octave - General mailing list archive at Nabble.com.
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://www-old.cae.wisc.edu/mailman/listinfo/help-octave