I was able to get the dggev routine from Lapack 3 to build with the rest of vnl.  I needed to grab the blaswrap.h from Lapack 3 so dggev would compile. (Don't know whether it works yet :)
I hesitate to check these in since we'd be mixing Lapack 3 files with Lapack 2 files which could be confusing to the users and maintainers.
-----Original Message-----
From: Miller, James V (Research)
Sent: Thursday, June 20, 2002 2:01 PM
To: Vxl-users (E-mail)
Subject: [Vxl-users] generalized eigenvectors

I need a generalized eigenvector solver (A*x = lambda*B*x) for the case where the matrix B is not necessarily positive definate.  The routine used by vnl_generalized_eigensystem requires the matrix B be positive definate.
Lapack version 3 has a routine (dggev) for solving this case.  This is also the Lapack routine used by MATLAB. It looks like vnl uses Lapack version 2.  Are there plans to upgrade vnl to use version 3 of Lapack?  Version 3 came out in 1999. 
I tried grabbing just this file from Clapack but as you might expect it does not compile with the rest of version 2.
There is also an Eispack routine for this problem rgg but vnl does not seem to have that routine either.

Jim Miller
Visualization & Computer Vision
GE Research
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P.O. Box 8, Schenectady NY 12301


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