Re: Problem with function geev

Raymond Toy <[email protected]> Tue, 16 Aug 2005 21:26:52 -0400
Newsgroups gmane.lisp.matlisp.user
Message-ID <[email protected]>
Paul Ledbetter III wrote:
>>Ah, thanks for digging into this.  A little googling finds the LAPACK
>>FAQ (http://www.netlib.org/lapack/faq.html) which indicates that dlamch
>>(and its dependent routines dlamc[1-5]) should be compiled without
>>optimization?  Can you compile dlamch.f by hand without optimization and
>>see if that makes a difference for you?
>>
>>I'd really appreciate if you could, since I don't seem to have this
>>problem on my linux boxes.
>>
> 
> 
> I recompiled with an unoptimized dlamch and this solved the problem as
> well.  So now we have found multiple ways to solve the problem, and
> this should do well for anyone wanting to use geev.  But in the
> following I argue that we still haven't found the real issue.
> 

[snip nice discussion]

I agree.  We haven't found the real issue.  However, since the LAPACK 
guys didn't change dlamch, I am reluctant to modify it.  Therefore, I 
think the right course is to do what the FAQ suggests and compile dlamch 
without optimization.

Ray



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