Re: CCL:Large matrix diagonalization.

["David E. Bernholdt" <bernhold "at@at" npac.syr.edu>]

The LAPACK library deals only with dense matrices, and is a de facto
 standard library for those operations on uniprocessors.
 Sparse linear algebra has a great deal of variation across fields and
 even across different applications, and is a lot less standardized at
 this point in time.  Likewise, parallel dense linear algebra is also a
 lot less standardized, though that area seems to be consolidating of
 late.
 Mounting soapbox...
 My (humble?) opinion is that chemists (speaking broadly) aren't very
 smart about solving their linear algbra problems.  I think it is
 getting better, along with the evolution of packages like LAPACK, but
 historically our track record is pretty poor.
 Chemists are all too willing to "roll their own" solutions to linear
 algebra problems, blithly ignoring the fact that there is an entire
 field of research that devotes itself to such problems.  To the extent
 possible, we should be (well-informed) consumers of the high quality,
 often highly optimized mainstream linear algebra packages that one can
 easily obtain from NETLIB or other sites.
 To be sure, there will be problems that the standard linear algebra
 tools don't handle well for one reason or another.  In that case, my
 recommendation is to make frieds with a good numerical analyst in the
 problem area.  My experience is that they like new challenges -- it
 pushes their research & their field along just as chemical challenges
 do ours, andby virute of their training, they're likely to come up
 with a better solution than you can working in isolation.  The more we
 chemists expose the numerical analysis community to our unique
 problems (relative to other fields), the more help we'll get from
 them, as chemically-derived problems become part of the standard test
 suites they use when testing new algorithms & libraries.
 Stepping off soapbox...
 --
 David E. Bernholdt                      | Email:  bernhold "at@at" npac.syr.edu
 Northeast Parallel Architectures Center | Phone:  +1 315 443 3857
 111 College Place, Syracuse University  | Fax:    +1 315 443 1973
 Syracuse, NY 13244-4100                 | URL:    http://www.npac.syr.edu