/* 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 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 "glpapi.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 */