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\chapter{Stand-alone LP/MIP Solver}
\label{chaglpsol}
The GLPK package includes the program \verb|glpsol|, which is a
stand-alone LP/MIP solver. This program can be invoked from the command
line to read LP/MIP problem data in any format supported by GLPK, solve
the problem, and write its solution to an output text file.
\para{Usage}
\verb|glpsol| [{\it options\dots}] [{\it filename}]
\para{General options}
\begin{verbatim}
--mps read LP/MIP problem in fixed MPS format
--freemps read LP/MIP problem in free MPS format (default)
--lp read LP/MIP problem in CPLEX LP format
--glp read LP/MIP problem in GLPK format
--math read LP/MIP model written in GNU MathProg modeling
language
-m filename, --model filename
read model section and optional data section from
filename (same as --math)
-d filename, --data filename
read data section from filename (for --math only);
if model file also has data section, it is ignored
-y filename, --display filename
send display output to filename (for --math only);
by default the output is sent to terminal
--seed value initialize pseudo-random number generator used in
MathProg model with specified seed (any integer);
if seed value is ?, some random seed will be used
--mincost read min-cost flow problem in DIMACS format
--maxflow read maximum flow problem in DIMACS format
--cnf read CNF-SAT problem in DIMACS format
--simplex use simplex method (default)
--interior use interior point method (LP only)
-r filename, --read filename
read solution from filename rather to find it with
the solver
--min minimization
--max maximization
--scale scale problem (default)
--noscale do not scale problem
-o filename, --output filename
write solution to filename in printable format
-w filename, --write filename
write solution to filename in plain text format
--ranges filename
write sensitivity analysis report to filename in
printable format (simplex only)
--tmlim nnn limit solution time to nnn seconds
--memlim nnn limit available memory to nnn megabytes
--check do not solve problem, check input data only
--name probname change problem name to probname
--wmps filename write problem to filename in fixed MPS format
--wfreemps filename
write problem to filename in free MPS format
--wlp filename write problem to filename in CPLEX LP format
--wglp filename write problem to filename in GLPK format
--wcnf filename write problem to filename in DIMACS CNF-SAT format
--log filename write copy of terminal output to filename
-h, --help display this help information and exit
-v, --version display program version and exit
\end{verbatim}
\para{LP basis factorization options}
\begin{verbatim}
--luf plain LU factorization (default)
--btf block triangular LU factorization
--ft Forrest-Tomlin update (requires --luf; default)
--cbg Schur complement + Bartels-Golub update
--cgr Schur complement + Givens rotation update
\end{verbatim}
\para{Options specific to the simplex solver}
\begin{verbatim}
--primal use primal simplex (default)
--dual use dual simplex
--std use standard initial basis of all slacks
--adv use advanced initial basis (default)
--bib use Bixby's initial basis
--ini filename use as initial basis previously saved with -w
(disables LP presolver)
--steep use steepest edge technique (default)
--nosteep use standard "textbook" pricing
--relax use Harris' two-pass ratio test (default)
--norelax use standard "textbook" ratio test
--presol use presolver (default; assumes --scale and --adv)
--nopresol do not use presolver
--exact use simplex method based on exact arithmetic
--xcheck check final basis using exact arithmetic
\end{verbatim}
\para{Options specific to the interior-point solver}
\begin{verbatim}
--nord use natural (original) ordering
--qmd use quotient minimum degree ordering
--amd use approximate minimum degree ordering (default)
--symamd use approximate minimum degree ordering
\end{verbatim}
\para{Options specific to the MIP solver}
\begin{verbatim}
--nomip consider all integer variables as continuous
(allows solving MIP as pure LP)
--first branch on first integer variable
--last branch on last integer variable
--mostf branch on most fractional variable
--drtom branch using heuristic by Driebeck and Tomlin
(default)
--pcost branch using hybrid pseudocost heuristic (may be
useful for hard instances)
--dfs backtrack using depth first search
--bfs backtrack using breadth first search
--bestp backtrack using the best projection heuristic
--bestb backtrack using node with best local bound
(default)
--intopt use MIP presolver (default)
--nointopt do not use MIP presolver
--binarize replace general integer variables by binary ones
(assumes --intopt)
--fpump apply feasibility pump heuristic
--proxy [nnn] apply proximity search heuristic (nnn is time limit
in seconds; default is 60)
--gomory generate Gomory's mixed integer cuts
--mir generate MIR (mixed integer rounding) cuts
--cover generate mixed cover cuts
--clique generate clique cuts
--cuts generate all cuts above
--mipgap tol set relative mip gap tolerance to tol
--minisat translate integer feasibility problem to CNF-SAT
and solve it with MiniSat solver
\end{verbatim}
\newpage
\begin{verbatim}
--objbnd bound add inequality obj <= bound (minimization) or
obj >= bound (maximization) to integer feasibility
problem (assumes --minisat)
\end{verbatim}
For description of the MPS format see Appendix \ref{champs}, page
\pageref{champs}.
For description of the CPLEX LP format see Appendix \ref{chacplex},
page \pageref{chacplex}.
For description of the modeling language see the document ``Modeling
Language GNU MathProg: Language Reference'' included in the GLPK
distribution.
For description of the DIMACS min-cost flow problem format and DIMACS
maximum flow problem format see the document ``GLPK: Graph and Network
Routines'' included in the GLPK distribution.
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