glpk 4.21 release information

[Andrew Makhorin]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

GLPK 4.21 -- Release Information
********************************

Release date: Aug 28, 2007

GLPK (GNU Linear Programming Kit) is intended for solving large-scale
linear programming (LP), mixed integer linear programming (MIP), and
other related problems. It is a set of routines written in ANSI C and
organized as a callable library.

In this release:

Additional reasons for calling the callback routine used in the MIP
solver (glp_intopt) were introduced. Currently the following reasons
are supported:

* request for subproblem selection
* request for preprocessing
* request for row generation
* request for heuristic solution
* request for cut generation
* request for branching
* better integer solution found

A basic preprocessing component used to improve subproblem formulations
by tightening bounds of variables was included in the MIP solver.
Depending on the control parameter pp_tech passed to the routine
glp_intopt the preprocessing can be performed either on the root level
or on all levels (default) or can be disabled.

Backtracking heuristic used by default in the MIP solver was changed to
the "best local bound".

For more details see Chapter "Advanced API routines", Section
"Branch-and-bound interface routines" in a new edition of the reference
manual included in the distribution.

See GLPK web page at <http://www.gnu.org/software/glpk/glpk.html>.

GLPK distribution can be ftp'ed from <ftp://ftp.gnu.org/gnu/glpk/> or
from some mirror ftp sites; see <http://www.gnu.org/order/ftp.html>.

MD5 check-sum is the following:

a41df71415c97fc5c541d19547ced10a *glpk-4.21.tar.gz

GLPK is also available as a Debian GNU/Linux package. See its web page
at <http://packages.debian.org/stable/math/glpk.html>.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (MingW32)

iD8DBQFG1Bmy0XvyMFmB6BgRAiqBAJ9tw133W6Jhpwyo0vQkHADzHml2FwCglZO8
RHzI0SafP3jW68Y6L0Sxqos=
=w/nQ
-----END PGP SIGNATURE-----