glpmpl04.c

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.

      mpl->phase = 2;
      xprintf("Reading data section from %s...\n", file);
      mpl->flag_d = 1;
      open_input(mpl, file);
      /* in this case the keyword 'data' is optional */
      if (is_literal(mpl, "data"))
      {  get_token(mpl /* data */);
         if (mpl->token != T_SEMICOLON)
            error(mpl, "semicolon missing where expected");
         get_token(mpl /* ; */);
      }
      data_section(mpl);
      /* process end statement */
      end_statement(mpl);
      xprintf("%d line%s were read\n",
         mpl->line, mpl->line == 1 ? "" : "s");
      close_input(mpl);
done: /* return to the calling program */
      return mpl->phase;
}

/*----------------------------------------------------------------------
-- mpl_generate - generate model.
--
-- *Synopsis*
--
-- #include "glpmpl.h"
-- int mpl_generate(MPL *mpl, char *file);
--
-- *Description*
--
-- The routine mpl_generate generates the model using its description
-- stored in the translator database. This phase means generating all
-- variables, constraints, and objectives, executing check and display
-- statements, which precede the solve statement (if it is presented),
-- and building the problem instance.
--
-- The character string file specifies the name of output text file, to
-- which output produced by display statements should be written. It is
-- allowed to specify NULL, in which case the output goes to stdout via
-- the routine print.
--
-- This routine should be called once after the routine mpl_read_model
-- or mpl_read_data and if one of the latters returned the code 2.
--
-- *Returns*
--
-- The routine mpl_generate returns one of the following codes:
--
-- 3 - model has been successfully generated. In this case the calling
--     program may call other api routines to obtain components of the
--     problem instance from the translator database.
-- 4 - processing failed due to some errors. In this case the calling
--     program should call the routine mpl_terminate to terminate model
--     processing. */

int mpl_generate(MPL *mpl, char *file)
{     if (!(mpl->phase == 1 || mpl->phase == 2))
         xfault("mpl_generate: invalid call sequence\n");
      /* set up error handler */
      if (setjmp(mpl->jump)) goto done;
      /* generate model */
      mpl->phase = 3;
      open_output(mpl, file);
      generate_model(mpl);
      flush_output(mpl);
      /* build problem instance */
      build_problem(mpl);
      /* generation phase has been finished */
      xprintf("Model has been successfully generated\n");
done: /* return to the calling program */
      return mpl->phase;
}

/*----------------------------------------------------------------------
-- mpl_get_prob_name - obtain problem (model) name.
--
-- *Synopsis*
--
-- #include "glpmpl.h"
-- char *mpl_get_prob_name(MPL *mpl);
--
-- *Returns*
--
-- The routine mpl_get_prob_name returns a pointer to internal buffer,
-- which contains symbolic name of the problem (model).
--
-- *Note*
--
-- Currently MathProg has no feature to assign a symbolic name to the
-- model. Therefore the routine mpl_get_prob_name tries to construct
-- such name using the name of input text file containing model section,
-- although this is not a good idea (due to portability problems). */

char *mpl_get_prob_name(MPL *mpl)
{     char *name = mpl->mpl_buf;
      char *file = mpl->mod_file;
      int k;
      if (mpl->phase != 3)
         xfault("mpl_get_prob_name: invalid call sequence\n");
      for (;;)
      {  if (strchr(file, '/') != NULL)
            file = strchr(file, '/') + 1;
         else if (strchr(file, '\\') != NULL)
            file = strchr(file, '\\') + 1;
         else if (strchr(file, ':') != NULL)
            file = strchr(file, ':') + 1;
         else
            break;
      }
      for (k = 0; ; k++)
      {  if (k == 255) break;
         if (!(isalnum((unsigned char)*file) || *file == '_')) break;
         name[k] = *file++;
      }
      if (k == 0)
         strcpy(name, "Unknown");
      else
         name[k] = '\0';
      xassert(strlen(name) <= 255);
      return name;
}

/*----------------------------------------------------------------------
-- mpl_get_num_rows - determine number of rows.
--
-- *Synopsis*
--
-- #include "glpmpl.h"
-- int mpl_get_num_rows(MPL *mpl);
--
-- *Returns*
--
-- The routine mpl_get_num_rows returns total number of rows in the
-- problem, where each row is an individual constraint or objective. */

int mpl_get_num_rows(MPL *mpl)
{     if (mpl->phase != 3)
         xfault("mpl_get_num_rows: invalid call sequence\n");
      return mpl->m;
}

/*----------------------------------------------------------------------
-- mpl_get_num_cols - determine number of columns.
--
-- *Synopsis*
--
-- #include "glpmpl.h"
-- int mpl_get_num_cols(MPL *mpl);
--
-- *Returns*
--
-- The routine mpl_get_num_cols returns total number of columns in the
-- problem, where each column is an individual variable. */

int mpl_get_num_cols(MPL *mpl)
{     if (mpl->phase != 3)
         xfault("mpl_get_num_cols: invalid call sequence\n");
      return mpl->n;
}

/*----------------------------------------------------------------------
-- mpl_get_row_name - obtain row name.
--
-- *Synopsis*
--
-- #include "glpmpl.h"
-- char *mpl_get_row_name(MPL *mpl, int i);
--
-- *Returns*
--
-- The routine mpl_get_row_name returns a pointer to internal buffer,
-- which contains symbolic name of i-th row of the problem. */

char *mpl_get_row_name(MPL *mpl, int i)
{     char *name = mpl->mpl_buf, *t;
      int len;
      if (mpl->phase != 3)
         xfault("mpl_get_row_name: invalid call sequence\n");
      if (!(1 <= i && i <= mpl->m))
         xfault("mpl_get_row_name: i = %d; row number out of range\n",
            i);
      strcpy(name, mpl->row[i]->con->name);
      len = strlen(name);
      xassert(len <= 255);
      t = format_tuple(mpl, '[', mpl->row[i]->memb->tuple);
      while (*t)
      {  if (len == 255) break;
         name[len++] = *t++;
      }
      name[len] = '\0';
      if (len == 255) strcpy(name+252, "...");
      xassert(strlen(name) <= 255);
      return name;
}

/*----------------------------------------------------------------------
-- mpl_get_row_kind - determine row kind.
--
-- *Synopsis*
--
-- #include "glpmpl.h"
-- int mpl_get_row_kind(MPL *mpl, int i);
--
-- *Returns*
--
-- The routine mpl_get_row_kind returns the kind of i-th row, which can
-- be one of the following:
--
-- MPL_ST  - non-free (constraint) row;
-- MPL_MIN - free (objective) row to be minimized;
-- MPL_MAX - free (objective) row to be maximized. */

int mpl_get_row_kind(MPL *mpl, int i)
{     int kind;
      if (mpl->phase != 3)
         xfault("mpl_get_row_kind: invalid call sequence\n");
      if (!(1 <= i && i <= mpl->m))
         xfault("mpl_get_row_kind: i = %d; row number out of range\n",
            i);
      switch (mpl->row[i]->con->type)
      {  case A_CONSTRAINT:
            kind = MPL_ST; break;
         case A_MINIMIZE:
            kind = MPL_MIN; break;
         case A_MAXIMIZE:
            kind = MPL_MAX; break;
         default:
            xassert(mpl != mpl);
      }
      return kind;
}

/*----------------------------------------------------------------------
-- mpl_get_row_bnds - obtain row bounds.
--
-- *Synopsis*
--
-- #include "glpmpl.h"
-- int mpl_get_row_bnds(MPL *mpl, int i, double *lb, double *ub);
--
-- *Description*
--
-- The routine mpl_get_row_bnds stores lower and upper bounds of i-th
-- row of the problem to the locations, which the parameters lb and ub
-- point to, respectively. Besides the routine returns the type of the
-- i-th row.
--
-- If some of the parameters lb and ub is NULL, the corresponding bound
-- value is not stored.
--
-- Types and bounds have the following meaning:
--
--     Type           Bounds          Note
--    -----------------------------------------------------------
--    MPL_FR   -inf <  f(x) <  +inf   Free linear form
--    MPL_LO     lb <= f(x) <  +inf   Inequality f(x) >= lb
--    MPL_UP   -inf <  f(x) <=  ub    Inequality f(x) <= ub
--    MPL_DB     lb <= f(x) <=  ub    Inequality lb <= f(x) <= ub
--    MPL_FX           f(x)  =  lb    Equality f(x) = lb
--
-- where f(x) is the corresponding linear form of the i-th row.
--
-- If the row has no lower bound, *lb is set to zero; if the row has
-- no upper bound, *ub is set to zero; and if the row is of fixed type,
-- both *lb and *ub are set to the same value.
--
-- *Returns*
--
-- The routine returns the type of the i-th row as it is stated in the
-- table above. */

int mpl_get_row_bnds(MPL *mpl, int i, double *_lb, double *_ub)
{     ELEMCON *con;
      int type;
      double lb, ub;
      if (mpl->phase != 3)
         xfault("mpl_get_row_bnds: invalid call sequence\n");
      if (!(1 <= i && i <= mpl->m))
         xfault("mpl_get_row_bnds: i = %d; row number out of range\n",
            i);
      con = mpl->row[i];
#if 0 /* 21/VII-2006 */
      if (con->con->lbnd == NULL && con->con->ubnd == NULL)
         type = MPL_FR, lb = ub = 0.0;
      else if (con->con->ubnd == NULL)
         type = MPL_LO, lb = con->lbnd, ub = 0.0;
      else if (con->con->lbnd == NULL)
         type = MPL_UP, lb = 0.0, ub = con->ubnd;
      else if (con->con->lbnd != con->con->ubnd)
         type = MPL_DB, lb = con->lbnd, ub = con->ubnd;
      else
         type = MPL_FX, lb = ub = con->lbnd;
#else
      lb = (con->con->lbnd == NULL ? -DBL_MAX : con->lbnd);
      ub = (con->con->ubnd == NULL ? +DBL_MAX : con->ubnd);
      if (lb == -DBL_MAX && ub == +DBL_MAX)
         type = MPL_FR, lb = ub = 0.0;
      else if (ub == +DBL_MAX)
         type = MPL_LO, ub = 0.0;
      else if (lb == -DBL_MAX)
         type = MPL_UP, lb = 0.0;
      else if (con->con->lbnd != con->con->ubnd)
         type = MPL_DB;
      else
         type = MPL_FX;
#endif
      if (_lb != NULL) *_lb = lb;
      if (_ub != NULL) *_ub = ub;
      return type;
}

/*----------------------------------------------------------------------
-- mpl_get_mat_row - obtain row of the constraint matrix.
--
-- *Synopsis*
--
-- #include "glpmpl.h"
-- int mpl_get_mat_row(MPL *mpl, int i, int ndx[], double val[]);
--
-- *Description*
--
-- The routine mpl_get_mat_row stores column indices and numeric values
-- of constraint coefficients for the i-th row to locations ndx[1], ...,
-- ndx[len] and val[1], ..., val[len], respectively, where 0 <= len <= n
-- is number of (structural) non-zero constraint coefficients, and n is
-- number of columns in the problem.
--
-- If the parameter ndx is NULL, column indices are not stored. If the
-- parameter val is NULL, numeric values are not stored.
--
-- Note that free rows may have constant terms, which are not part of
-- the constraint matrix and therefore not reported by this routine. The
-- constant term of a particular row can be obtained, if necessary, via
-- the routine mpl_get_row_c0.
--
-- *Returns*
--
-- The routine mpl_get_mat_row returns len, which is length of i-th row
-- of the constraint matrix (i.e. number of non-zero coefficients). */

int mpl_get_mat_row(MPL *mpl, int i, int ndx[], double val[])
{     FORMULA *term;
      int len = 0;
      if (mpl->phase != 3)
         xfault("mpl_get_mat_row: invalid call sequence\n");
      if (!(1 <= i && i <= mpl->m))
         xfault("mpl_get_mat_row: i = %d; row number out of range\n",
            i);
      for (term = mpl->row[i]->form; term != NULL; term = term->next)
      {  xassert(term->var != NULL);
         len++;
         xassert(len <= mpl->n);
         if (ndx != NULL) ndx[len] = term->var->j;
         if (val != NULL) val[len] = term->coef;
      }