Quick comment: the lapack distributed with J Windows was built from lapack
source from several years ago. There have been serveral updates to the
source since then. Unix Lapack tends to be part of of the distribution and
is likely more current. Perhaps we (Jsoftware) should distribute a more
current windows lapack, but this is probably an area where user contribution
would be a better route. That is, someone with interest and knowledge should
build a current Windows Lapack (assuming this isn't simply a matter of
providing a pointer to someone else who already does this) and provide the
links and downloads.
----- Original Message -----
From: "John Randall" <[EMAIL PROTECTED]>
To: "Programming forum" <[email protected]>
Sent: Friday, March 03, 2006 7:16 AM
Subject: Re: [Jprogramming] LAPACK question: principal eigenvector
There do seem to be slight variations between results from the Windows and
Linux versions of LAPACK. They are mathematically insignificant, but have
an effect if you are erroneously relying on order of results. Here's my
revised code for calculating a principal eigenvector using LAPACK.
require '~addons/lapack/lapack.ijs'
require '~addons/lapack/dgeev.ijs'
la=:3 : 0
'l c r'=.dgeev_jlapack_ y.
({. \: c){"1 r
)
und=: >(1,1,5);(1,1,3);((%5),(%3),1) NB. "Understandability
(%+/)power und
0.48064 0.405388 0.113972
%+/)la und
0.48064 0.405388 0.113972
Best wishes,
John
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