glpk03.tex

著名的大规模线性规划求解器源码GLPK.C语言版本,可以修剪.内有详细帮助文档.

      int sol);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|glp_mpl_postsolve| copies the solution from the
specified problem object \verb|prob| to the translator workspace and
then executes all the remaining model statements, which follow the
solve statement.

The parameter \verb|sol| specifies which solution should be copied
from the problem object to the workspace as follows:

\begin{tabular}{@{}ll}
\verb|GLP_SOL| & basic solution; \\
\verb|GLP_IPT| & interior-point solution; \\
\verb|GLP_MIP| & mixed integer solution. \\
\end{tabular}

\subsubsection*{Returns}

If the operation is successful, the routine returns zero. Otherwise
the routine prints an error message and returns non-zero.

\subsection{glp\_mpl\_free\_wksp---free the translator workspace}

\subsubsection*{Synopsis}

\begin{verbatim}
void glp_mpl_free_wksp(glp_tran *tran);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|glp_mpl_free_wksp| frees all the memory allocated to
the translator workspace. It also frees all other resources, which are
still used by the translator.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newpage

\section{Problem solution reading/writing routines}

\subsection{lpx\_print\_sol---write basic solution in printable
format}

\subsubsection*{Synopsis}

\begin{verbatim}
int lpx_print_sol(glp_prob *lp, char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|lpx_print_sol writes| the current basic solution of
an LP problem, which is specified by the pointer \verb|lp|, to a text
file, whose name is the character string \verb|fname|, in printable
format.

Information reported by the routine \verb|lpx_print_sol| is intended
mainly for visual analysis.

\subsubsection*{Returns}

If no errors occurred, the routine returns zero. Otherwise the routine
prints an error message and returns non-zero.

\subsection{lpx\_print\_sens\_bnds---write bounds sensitivity
information}

\subsubsection*{Synopsis}

\begin{verbatim}
int lpx_print_sens_bnds(glp_prob *lp, char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|lpx_print_sens_bnds| writes the bounds for objective
coefficients, right-hand-sides of constraints, and variable bounds
for which the current optimal basic solution remains optimal (for LP
only).

The LP is given by the pointer \verb|lp|, and the output is written to
the file specified by \verb|fname|.  The current contents of the file
will be overwritten.

Information reported by the routine \verb|lpx_print_sens_bnds| is
intended mainly for visual analysis.

\subsubsection*{Returns}

If no errors occurred, the routine returns zero. Otherwise the routine
prints an error message and returns non-zero.

\subsection{lpx\_print\_ips---write interior-point solution in
printable format}

\subsubsection*{Synopsis}

\begin{verbatim}
int lpx_print_ips(glp_prob *lp, char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|lpx_print_ips| writes the current interior point
solution  of an LP problem, which the parameter \verb|lp| points to, to
a text file, whose name is the character string \verb|fname|, in
printable format.

Information reported by the routine \verb|lpx_print_ips| is intended
mainly  for visual analysis.

\subsubsection*{Returns}

If no errors occurred, the routine returns zero. Otherwise the routine
prints an error message and returns non-zero.

\subsection{lpx\_print\_mip---write MIP solution in printable format}

\subsubsection*{Synopsis}

\begin{verbatim}
int lpx_print_mip(glp_prob *lp, char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|lpx_print_mip| writes a best known integer solution
of a MIP problem, which is specified by the pointer \verb|lp|, to a text
file, whose name is the character string \verb|fname|, in printable
format.

Information reported by the routine \verb|lpx_print_mip| is intended
mainly for visual analysis.

\subsubsection*{Returns}

If no errors occurred, the routine returns zero. Otherwise the routine
prints an error message and returns non-zero.

\pagebreak

\subsection{glp\_read\_sol---read basic solution from text file}

\subsubsection*{Synopsis}

\begin{verbatim}
int glp_read_sol(glp_prob *lp, const char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|glp_read_sol| reads basic solution from a text file
whose name is specified by the parameter \verb|fname| into the problem
object.

For the file format see description of the routine \verb|glp_write_sol|.

\subsubsection*{Returns}

On success the routine returns zero, otherwise non-zero.

\subsection{glp\_write\_sol---write basic solution to text file}

\subsubsection*{Synopsis}

\begin{verbatim}
int glp_write_sol(glp_prob *lp, const char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|glp_write_sol| writes the current basic solution to a
text file whose name is specified by the parameter \verb|fname|. This
file can be read back with the routine \verb|glp_read_sol|.

\subsubsection*{Returns}

On success the routine returns zero, otherwise non-zero.

\subsubsection*{File format}

The file created by the routine \verb|glp_write_sol| is a plain text
file, which contains the following information:

\begin{verbatim}
   m n
   p_stat d_stat obj_val
   r_stat[1] r_prim[1] r_dual[1]
   . . .
   r_stat[m] r_prim[m] r_dual[m]
   c_stat[1] c_prim[1] c_dual[1]
   . . .
   c_stat[n] c_prim[n] c_dual[n]
\end{verbatim}

\noindent
where:

\noindent
$m$ is the number of rows (auxiliary variables);

\noindent
$n$ is the number of columns (structural variables);

\noindent
\verb|p_stat| is the primal status of the basic solution
(\verb|GLP_UNDEF| = 1, \verb|GLP_FEAS| = 2, \verb|GLP_INFEAS| = 3, or
\verb|GLP_NOFEAS| = 4);

\noindent
\verb|d_stat| is the dual status of the basic solution
(\verb|GLP_UNDEF| = 1, \verb|GLP_FEAS| = 2, \verb|GLP_INFEAS| = 3, or
\verb|GLP_NOFEAS| = 4);

\noindent
\verb|obj_val| is the objective value;

\noindent
\verb|r_stat[i]|, $i=1,\dots,m$, is the status of $i$-th row
(\verb|GLP_BS| = 1, \verb|GLP_NL| = 2, \verb|GLP_NU| = 3,
\verb|GLP_NF| = 4, or \verb|GLP_NS| = 5);

\noindent
\verb|r_prim[i]|, $i=1,\dots,m$, is the primal value of $i$-th row;

\noindent
\verb|r_dual[i]|, $i=1,\dots,m$, is the dual value of $i$-th row;

\noindent
\verb|c_stat[j]|, $j=1,\dots,n$, is the status of $j$-th column
(\verb|GLP_BS| = 1, \verb|GLP_NL| = 2, \verb|GLP_NU| = 3,
\verb|GLP_NF| = 4, or \verb|GLP_NS| = 5);

\noindent
\verb|c_prim[j]|, $j=1,\dots,n$, is the primal value of $j$-th column;

\noindent
\verb|c_dual[j]|, $j=1,\dots,n$, is the dual value of $j$-th column.

\subsection{glp\_read\_ipt---read interior-point solution from text
file}

\subsubsection*{Synopsis}

\begin{verbatim}
int glp_read_ipt(glp_prob *lp, const char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|glp_read_ipt| reads interior-point solution from a
text file whose name is specified by the parameter \verb|fname| into the
problem object.

For the file format see description of the routine \verb|glp_write_ipt|.

\subsubsection*{Returns}

On success the routine returns zero, otherwise non-zero.

\pagebreak

\subsection{glp\_write\_ipt---write interior-point solution to text
file}

\subsubsection*{Synopsis}

\begin{verbatim}
int glp_write_ipt(glp_prob *lp, const char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|glp_write_ipt| writes the current interior-point
solution to a text file whose name is specified by the parameter
\verb|fname|. This file can be read back with the routine
\verb|glp_read_ipt|.

\subsubsection*{Returns}

On success the routine returns zero, otherwise non-zero.

\subsubsection*{File format}

The file created by the routine \verb|glp_write_ipt| is a plain text
file, which contains the following information:

\begin{verbatim}
   m n
   stat obj_val
   r_prim[1] r_dual[1]
   . . .
   r_prim[m] r_dual[m]
   c_prim[1] c_dual[1]
   . . .
   c_prim[n] c_dual[n]
\end{verbatim}

\noindent
where:

\noindent
$m$ is the number of rows (auxiliary variables);

\noindent
$n$ is the number of columns (structural variables);

\noindent
\verb|stat| is the solution status (\verb|GLP_UNDEF| = 1 or
\verb|GLP_OPT| = 5);

\noindent
\verb|obj_val| is the objective value;

\noindent
\verb|r_prim[i]|, $i=1,\dots,m$, is the primal value of $i$-th row;

\noindent
\verb|r_dual[i]|, $i=1,\dots,m$, is the dual value of $i$-th row;

\noindent
\verb|c_prim[j]|, $j=1,\dots,n$, is the primal value of $j$-th column;

\noindent
\verb|c_dual[j]|, $j=1,\dots,n$, is the dual value of $j$-th column.

\subsection{glp\_read\_mip---read MIP solution from text file}

\subsubsection*{Synopsis}

\begin{verbatim}
int glp_read_mip(glp_prob *mip, const char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|glp_read_mip| reads MIP solution from a text file
whose name is specified by the parameter \verb|fname| into the problem
object.

For the file format see description of the routine \verb|glp_write_mip|.

\subsubsection*{Returns}

On success the routine returns zero, otherwise non-zero.

\subsection{glp\_write\_mip---write MIP solution to text file}

\subsubsection*{Synopsis}

\begin{verbatim}
int glp_write_mip(glp_prob *mip, const char *fname);
\end{verbatim}

\subsubsection*{Description}

The routine \verb|glp_write_mip| writes the current MIP solution to a
text file whose name is specified by the parameter \verb|fname|. This
file can be read back with the routine \verb|glp_read_mip|.

\subsubsection*{Returns}

On success the routine returns zero, otherwise non-zero.

\subsubsection*{File format}

The file created by the routine \verb|glp_write_sol| is a plain text
file, which contains the following information:

\begin{verbatim}
   m n
   stat obj_val
   r_val[1]
   . . .
   r_val[m]
   c_val[1]
   . . .
   c_val[n]
\end{verbatim}

\noindent
where:

\noindent
$m$ is the number of rows (auxiliary variables);

\noindent
$n$ is the number of columns (structural variables);

\noindent
\verb|stat| is the solution status (\verb|GLP_UNDEF| = 1,
\verb|GLP_FEAS| = 2, \verb|GLP_NOFEAS| = 4, or \verb|GLP_OPT| = 5);

\noindent
\verb|obj_val| is the objective value;

\noindent
\verb|r_val[i]|, $i=1,\dots,m$, is the value of $i$-th row;

\noindent
\verb|c_val[j]|, $j=1,\dots,n$, is the value of $j$-th column.

%* eof *%