Subject: Re: CCL:Re: CCL:MATRIX ALGEBRA PROGRAM

From: [email-masked] (Hinsen Konrad)
Date: Tue, 12 Dec 1995 08:36:51 -0500

That's what I did (including the library itself :-( reinventing the wheel)
   but I am NOT sorry, because it is very convenient to be able to work
   with matrices just from the UNIX shell (with these tools) instead of writing
   programs for each case: i.e.
   (imaginary UNIX session)
   do some calculations,
   obtain some numerical results,
   use a tiny self-written tool to extract data from e.g. GAMESS or G94 output,
   mat_mult <file with A> <file with B> > C
   mat_eigval <C> > Ceigval
   look at the eigenvalues,
   continue work,...

There are several high-level matrix languages designed for exactly
this kind of use. The best known is probably Matlab and its many
clones, some of which are free (e.g. the GNU-clone called octave).
There are also a few such languages that improve on Matlab's most
obvious limitation, namely that matrices can only be two-dimensional.
Check http://lusk1.mines.edu/hjjou/linux_prg.html for a list (it
claims to be for Linux, but most of these packages are available for
all Unix systems).

One problem with these matrix languages is that they neglect other
aspects of programming, most notably flexible I/O and interfacing with
other programs. It would be a pain to write Matlab code to extract
something from a Gaussian output file, for example. Which is why my
favourite for such operations is Python.

Python is a high-level object-oriented language designed for scripting
and rapid prototyping (see http://www.python.org for details), and the
implementation works on all relevant platforms and is completely free
(there's not even a GNU-style "copyleft"). It has all the features of
a scripting language (easy string and file handling, regular
expressions etc.), but is also easily extensible in C or C++. One such
extension which is being worked on now is a matrix-handling facility
that makes numerical computations very convenient. Howeve, it is
not yet available to the general public; if you want to try it
you have to join the Matrix-SIG (which costs you just an e-mail);
see the Python home page for details.

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Konrad Hinsen                     | E-Mail: [email-masked]
Departement de chimie             | Tel.: +1-514-343-6111 ext. 3953
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From: [email-masked] (Hinsen Konrad)
Date: Tue, 12 Dec 1995 08:36:51 -0500

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From: "William T. Winter" <[email-masked]>
Date: Tue, 12 Dec 1995 15:26:05 -0500 (EST)

For access to a huge collection of matrix algebra and other mathematical 
libraries point your web browser at
http://www.netlib.org/liblist.html
EISPACK, LAPACK, LINPACK etc etc  its all here and downloadable through 
the web.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Dr. William T. Winter                  Phone: (315)470-6876
315 Baker Lab                          FAX:   (315)470-6856
SUNY-ESF                               Internet: [email-masked]
Syracuse, NY 13210-2786                URL     http://www-chem.esf.edu