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/* glpapi02.c (problem retrieving routines) */
/***********************************************************************
* This code is part of GLPK (GNU Linear Programming Kit).
*
* Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
* 2009, 2010, 2011, 2013 Andrew Makhorin, Department for Applied
* Informatics, Moscow Aviation Institute, Moscow, Russia. All rights
* reserved. E-mail: <mao@gnu.org>.
*
* GLPK is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GLPK is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
* License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GLPK. If not, see <http://www.gnu.org/licenses/>.
***********************************************************************/
#include "env.h"
#include "prob.h"
/***********************************************************************
* NAME
*
* glp_get_prob_name - retrieve problem name
*
* SYNOPSIS
*
* const char *glp_get_prob_name(glp_prob *lp);
*
* RETURNS
*
* The routine glp_get_prob_name returns a pointer to an internal
* buffer, which contains symbolic name of the problem. However, if the
* problem has no assigned name, the routine returns NULL. */
const char *glp_get_prob_name(glp_prob *lp)
{ char *name;
name = lp->name;
return name;
}
/***********************************************************************
* NAME
*
* glp_get_obj_name - retrieve objective function name
*
* SYNOPSIS
*
* const char *glp_get_obj_name(glp_prob *lp);
*
* RETURNS
*
* The routine glp_get_obj_name returns a pointer to an internal
* buffer, which contains a symbolic name of the objective function.
* However, if the objective function has no assigned name, the routine
* returns NULL. */
const char *glp_get_obj_name(glp_prob *lp)
{ char *name;
name = lp->obj;
return name;
}
/***********************************************************************
* NAME
*
* glp_get_obj_dir - retrieve optimization direction flag
*
* SYNOPSIS
*
* int glp_get_obj_dir(glp_prob *lp);
*
* RETURNS
*
* The routine glp_get_obj_dir returns the optimization direction flag
* (i.e. "sense" of the objective function):
*
* GLP_MIN - minimization;
* GLP_MAX - maximization. */
int glp_get_obj_dir(glp_prob *lp)
{ int dir = lp->dir;
return dir;
}
/***********************************************************************
* NAME
*
* glp_get_num_rows - retrieve number of rows
*
* SYNOPSIS
*
* int glp_get_num_rows(glp_prob *lp);
*
* RETURNS
*
* The routine glp_get_num_rows returns the current number of rows in
* the specified problem object. */
int glp_get_num_rows(glp_prob *lp)
{ int m = lp->m;
return m;
}
/***********************************************************************
* NAME
*
* glp_get_num_cols - retrieve number of columns
*
* SYNOPSIS
*
* int glp_get_num_cols(glp_prob *lp);
*
* RETURNS
*
* The routine glp_get_num_cols returns the current number of columns
* in the specified problem object. */
int glp_get_num_cols(glp_prob *lp)
{ int n = lp->n;
return n;
}
/***********************************************************************
* NAME
*
* glp_get_row_name - retrieve row name
*
* SYNOPSIS
*
* const char *glp_get_row_name(glp_prob *lp, int i);
*
* RETURNS
*
* The routine glp_get_row_name returns a pointer to an internal
* buffer, which contains symbolic name of i-th row. However, if i-th
* row has no assigned name, the routine returns NULL. */
const char *glp_get_row_name(glp_prob *lp, int i)
{ char *name;
if (!(1 <= i && i <= lp->m))
xerror("glp_get_row_name: i = %d; row number out of range\n",
i);
name = lp->row[i]->name;
return name;
}
/***********************************************************************
* NAME
*
* glp_get_col_name - retrieve column name
*
* SYNOPSIS
*
* const char *glp_get_col_name(glp_prob *lp, int j);
*
* RETURNS
*
* The routine glp_get_col_name returns a pointer to an internal
* buffer, which contains symbolic name of j-th column. However, if j-th
* column has no assigned name, the routine returns NULL. */
const char *glp_get_col_name(glp_prob *lp, int j)
{ char *name;
if (!(1 <= j && j <= lp->n))
xerror("glp_get_col_name: j = %d; column number out of range\n"
, j);
name = lp->col[j]->name;
return name;
}
/***********************************************************************
* NAME
*
* glp_get_row_type - retrieve row type
*
* SYNOPSIS
*
* int glp_get_row_type(glp_prob *lp, int i);
*
* RETURNS
*
* The routine glp_get_row_type returns the type of i-th row, i.e. the
* type of corresponding auxiliary variable, as follows:
*
* GLP_FR - free (unbounded) variable;
* GLP_LO - variable with lower bound;
* GLP_UP - variable with upper bound;
* GLP_DB - double-bounded variable;
* GLP_FX - fixed variable. */
int glp_get_row_type(glp_prob *lp, int i)
{ if (!(1 <= i && i <= lp->m))
xerror("glp_get_row_type: i = %d; row number out of range\n",
i);
return lp->row[i]->type;
}
/***********************************************************************
* NAME
*
* glp_get_row_lb - retrieve row lower bound
*
* SYNOPSIS
*
* double glp_get_row_lb(glp_prob *lp, int i);
*
* RETURNS
*
* The routine glp_get_row_lb returns the lower bound of i-th row, i.e.
* the lower bound of corresponding auxiliary variable. However, if the
* row has no lower bound, the routine returns -DBL_MAX. */
double glp_get_row_lb(glp_prob *lp, int i)
{ double lb;
if (!(1 <= i && i <= lp->m))
xerror("glp_get_row_lb: i = %d; row number out of range\n", i);
switch (lp->row[i]->type)
{ case GLP_FR:
case GLP_UP:
lb = -DBL_MAX; break;
case GLP_LO:
case GLP_DB:
case GLP_FX:
lb = lp->row[i]->lb; break;
default:
xassert(lp != lp);
}
return lb;
}
/***********************************************************************
* NAME
*
* glp_get_row_ub - retrieve row upper bound
*
* SYNOPSIS
*
* double glp_get_row_ub(glp_prob *lp, int i);
*
* RETURNS
*
* The routine glp_get_row_ub returns the upper bound of i-th row, i.e.
* the upper bound of corresponding auxiliary variable. However, if the
* row has no upper bound, the routine returns +DBL_MAX. */
double glp_get_row_ub(glp_prob *lp, int i)
{ double ub;
if (!(1 <= i && i <= lp->m))
xerror("glp_get_row_ub: i = %d; row number out of range\n", i);
switch (lp->row[i]->type)
{ case GLP_FR:
case GLP_LO:
ub = +DBL_MAX; break;
case GLP_UP:
case GLP_DB:
case GLP_FX:
ub = lp->row[i]->ub; break;
default:
xassert(lp != lp);
}
return ub;
}
/***********************************************************************
* NAME
*
* glp_get_col_type - retrieve column type
*
* SYNOPSIS
*
* int glp_get_col_type(glp_prob *lp, int j);
*
* RETURNS
*
* The routine glp_get_col_type returns the type of j-th column, i.e.
* the type of corresponding structural variable, as follows:
*
* GLP_FR - free (unbounded) variable;
* GLP_LO - variable with lower bound;
* GLP_UP - variable with upper bound;
* GLP_DB - double-bounded variable;
* GLP_FX - fixed variable. */
int glp_get_col_type(glp_prob *lp, int j)
{ if (!(1 <= j && j <= lp->n))
xerror("glp_get_col_type: j = %d; column number out of range\n"
, j);
return lp->col[j]->type;
}
/***********************************************************************
* NAME
*
* glp_get_col_lb - retrieve column lower bound
*
* SYNOPSIS
*
* double glp_get_col_lb(glp_prob *lp, int j);
*
* RETURNS
*
* The routine glp_get_col_lb returns the lower bound of j-th column,
* i.e. the lower bound of corresponding structural variable. However,
* if the column has no lower bound, the routine returns -DBL_MAX. */
double glp_get_col_lb(glp_prob *lp, int j)
{ double lb;
if (!(1 <= j && j <= lp->n))
xerror("glp_get_col_lb: j = %d; column number out of range\n",
j);
switch (lp->col[j]->type)
{ case GLP_FR:
case GLP_UP:
lb = -DBL_MAX; break;
case GLP_LO:
case GLP_DB:
case GLP_FX:
lb = lp->col[j]->lb; break;
default:
xassert(lp != lp);
}
return lb;
}
/***********************************************************************
* NAME
*
* glp_get_col_ub - retrieve column upper bound
*
* SYNOPSIS
*
* double glp_get_col_ub(glp_prob *lp, int j);
*
* RETURNS
*
* The routine glp_get_col_ub returns the upper bound of j-th column,
* i.e. the upper bound of corresponding structural variable. However,
* if the column has no upper bound, the routine returns +DBL_MAX. */
double glp_get_col_ub(glp_prob *lp, int j)
{ double ub;
if (!(1 <= j && j <= lp->n))
xerror("glp_get_col_ub: j = %d; column number out of range\n",
j);
switch (lp->col[j]->type)
{ case GLP_FR:
case GLP_LO:
ub = +DBL_MAX; break;
case GLP_UP:
case GLP_DB:
case GLP_FX:
ub = lp->col[j]->ub; break;
default:
xassert(lp != lp);
}
return ub;
}
/***********************************************************************
* NAME
*
* glp_get_obj_coef - retrieve obj. coefficient or constant term
*
* SYNOPSIS
*
* double glp_get_obj_coef(glp_prob *lp, int j);
*
* RETURNS
*
* The routine glp_get_obj_coef returns the objective coefficient at
* j-th structural variable (column) of the specified problem object.
*
* If the parameter j is zero, the routine returns the constant term
* ("shift") of the objective function. */
double glp_get_obj_coef(glp_prob *lp, int j)
{ if (!(0 <= j && j <= lp->n))
xerror("glp_get_obj_coef: j = %d; column number out of range\n"
, j);
return j == 0 ? lp->c0 : lp->col[j]->coef;
}
/***********************************************************************
* NAME
*
* glp_get_num_nz - retrieve number of constraint coefficients
*
* SYNOPSIS
*
* int glp_get_num_nz(glp_prob *lp);
*
* RETURNS
*
* The routine glp_get_num_nz returns the number of (non-zero) elements
* in the constraint matrix of the specified problem object. */
int glp_get_num_nz(glp_prob *lp)
{ int nnz = lp->nnz;
return nnz;
}
/***********************************************************************
* NAME
*
* glp_get_mat_row - retrieve row of the constraint matrix
*
* SYNOPSIS
*
* int glp_get_mat_row(glp_prob *lp, int i, int ind[], double val[]);
*
* DESCRIPTION
*
* The routine glp_get_mat_row scans (non-zero) elements of i-th row
* of the constraint matrix of the specified problem object and stores
* their column indices and numeric values to locations ind[1], ...,
* ind[len] and val[1], ..., val[len], respectively, where 0 <= len <= n
* is the number of elements in i-th row, n is the number of columns.
*
* The parameter ind and/or val can be specified as NULL, in which case
* corresponding information is not stored.
*
* RETURNS
*
* The routine glp_get_mat_row returns the length len, i.e. the number
* of (non-zero) elements in i-th row. */
int glp_get_mat_row(glp_prob *lp, int i, int ind[], double val[])
{ GLPAIJ *aij;
int len;
if (!(1 <= i && i <= lp->m))
xerror("glp_get_mat_row: i = %d; row number out of range\n",
i);
len = 0;
for (aij = lp->row[i]->ptr; aij != NULL; aij = aij->r_next)
{ len++;
if (ind != NULL) ind[len] = aij->col->j;
if (val != NULL) val[len] = aij->val;
}
xassert(len <= lp->n);
return len;
}
/***********************************************************************
* NAME
*
* glp_get_mat_col - retrieve column of the constraint matrix
*
* SYNOPSIS
*
* int glp_get_mat_col(glp_prob *lp, int j, int ind[], double val[]);
*
* DESCRIPTION
*
* The routine glp_get_mat_col scans (non-zero) elements of j-th column
* of the constraint matrix of the specified problem object and stores
* their row indices and numeric values to locations ind[1], ...,
* ind[len] and val[1], ..., val[len], respectively, where 0 <= len <= m
* is the number of elements in j-th column, m is the number of rows.
*
* The parameter ind or/and val can be specified as NULL, in which case
* corresponding information is not stored.
*
* RETURNS
*
* The routine glp_get_mat_col returns the length len, i.e. the number
* of (non-zero) elements in j-th column. */
int glp_get_mat_col(glp_prob *lp, int j, int ind[], double val[])
{ GLPAIJ *aij;
int len;
if (!(1 <= j && j <= lp->n))
xerror("glp_get_mat_col: j = %d; column number out of range\n",
j);
len = 0;
for (aij = lp->col[j]->ptr; aij != NULL; aij = aij->c_next)
{ len++;
if (ind != NULL) ind[len] = aij->row->i;
if (val != NULL) val[len] = aij->val;
}
xassert(len <= lp->m);
return len;
}
/* eof */