Hi,
On Fri, Feb 15, 2013 at 2:08 AM, kurisaki
<kurisaki.ncube.human.nagoya-u.ac.jp> wrote:
> Would you tell me algorithm which ptraj uses for solvation of eigen-value
> problem,
If you're asking for all of the eigenvalues/eigenvectors in the
system, ptraj calls the dspev routine from LAPACK, which I believe
uses the QR algorithm. If you're asking for a subset of eigenvectors,
ptraj calls the dsaupd/dseupd routines from ARPACK, which use the
Implictly Restarted Arnoldi/Lanczos Method.
> On the other hand, does the last eigen vector tend to take
> Some specific direction in ptraj?
The sign of an eigenvector is arbitrary, so I'm not clear on what you
mean here. If you provide your exact ptraj input and output we may be
able to provide more information.
-Dan
--
-------------------------
Daniel R. Roe, PhD
Department of Medicinal Chemistry
University of Utah
30 South 2000 East, Room 201
Salt Lake City, UT 84112-5820
http://home.chpc.utah.edu/~cheatham/
(801) 587-9652
(801) 585-9119 (Fax)
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Received on Fri Feb 15 2013 - 08:00:02 PST
