The PCx primal-dual interior-point linear programming solver can now be called from the mathematical programming language AMPL. Users of AMPL can now select PCx as a solver, and can set the various parameters for PCx within the AMPL environment.
Installation is easiest if you download the appropriate precompiled executable PCx for your system. You can obtain this from the PCx Download Page (if you don't have a password, submit a request through the request form). We currently have precompiled executables for Linux, Solaris, Sun, HP, and Irix systenms. If you have some other system, you can build PCx from the source code, but you must first download and install the solver interface code for AMPL, available here.
Once PCx is downloaded or compiled, running AMPL in the same directory as PCx will allow you to use PCx as AMPL's linear programming solver.
PCx can be selected as the solver of choice by entering
options solver pcx
from the ampl: prompt. The various parameters and options that PCx supports may be changed by setting the pcx_options variable appropriately, for example,
options pcx_options 'cachesize=8 presolve=no iterationlimit=50'
In general, pcx_options should contain terms of the form keyword=value. The names of the keywords are the same as those listed in the PCx User Guide, except for the fact that they are lowercase.
The README file describes installation and usage of the AMPL-PCx interface. For details on PCx itself, see the PCx User Guide.
The AMPL-PCx interface was written by Nathan Brixius. It was revised in Dec 2001 by Stephen Wright.
For contributors to PCx itself, see the PCx home page.
The general PCx Copyright Statement applies also to the AMPL interface.
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