Solver "lpsolve" is based on lp_solve, a simplex-based code for linear
and integer programming problems originally by
Michel Berkelaar
michel@es.ele.tue.nl
whose source was
ftp://ftp.es.ele.tue.nl/pub/lp_solve/lp_solve.tar.gz
The version of this source file that was available on 26 Feb. 2003 is
file lp_solve_4.0.tar.gz
(/netlib/ampl/solvers/lpsolve/lp_solve_4.0.tar.gz), which was released
under the LGPL license (as explained in its README and LGPL.txt
files). Some executable "lpsolve" binaries built from this source
appear in the system-dependent subdirectories of
/netlib/ampl/student/solvers. Sample makefiles makefile4.u and
makefile4.vc are for LP_SOLVE 4.0 under Linux and MS Windows.
More recently, source for an updated LP_SOLVE (e.g., version 5.5.2)
can be found at http://sourceforge.net/projects/lpsolve/ .
Sample makefiles makefile.u (for Linux) and makefile.vc (for MS Windows)
are for LP_SOLVE 5.5.2.
For a summary of using solver "lpsolve", execute
lpsolve '-?'
Lpsolve reads keywords and values from the environment (shell) variable
lpsolve_options (known in an AMPL session as option lpsolve_options) and
from the command line. Execute
lpsolve -=
for a summary of keywords that lpsolve recognizes.
Here is a table of solve_result_num values that "lpsolve" can return
to an AMPL session, along with the text that appears in the associated
solve_message.
Value Message
0 optimal
200 infeasible
300 unbounded
500 bug
501 failure
502 integer programming failure
Questions about this stuff? Contact dmg@ampl.com (David M. Gay).