glpmps01.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.

            double lb, ub, rhs;
            if (i == 0)
               typx = LPX_FR, lb = ub = 0.0;
            else
               lpx_get_row_bnds(lp, i, &typx, &lb, &ub);
            switch (typx)
            {  case LPX_FR:
                  rhs = (make_obj && i == 0 ? obj[0] : 0.0); break;
               case LPX_LO:
                  rhs = lb; break;
               case LPX_UP:
                  rhs = ub; break;
               case LPX_DB:
                  rhs = (ub > 0.0 ? lb : ub); break;
               case LPX_FX:
                  rhs = lb; break;
               default:
                  xassert(typx != typx);
            }
            if (rhs == 0.0) continue;
            if (!flag) xfprintf(fp, "RHS\n"), flag = 1;
            if (nl)
                xfprintf(fp, "    %-8s  ", vname);
            else
                xfprintf(fp, "   ");
            xfprintf(fp, "%-8s  %12s",
               row_name(lp, i, rname), mps_numb(rhs, numb));
            if (wide) nl = 1 - nl;
            if (nl) xfprintf(fp, "\n");
         }
         if (!nl) xfprintf(fp, "\n");
      }
      xfree(obj);
      /* write RANGES section */
      flag = 0;
      {  int nl = 1;
         strcpy(vname, frei ? "" : "RNG1");
         for (i = 1; i <= nrows; i++)
         {  int typx;
            double lb, ub, rng;
            lpx_get_row_bnds(lp, i, &typx, &lb, &ub);
            if (typx != LPX_DB) continue;
            if (!flag) xfprintf(fp, "RANGES\n"), flag = 1;
            if (nl)
                xfprintf(fp, "    %-8s  ", vname);
            else
                xfprintf(fp, "   ");
            rng = (ub > 0.0 ? ub - lb : lb - ub);
            xfprintf(fp, "%-8s  %12s",
               row_name(lp, i, rname), mps_numb(rng, numb));
            if (wide) nl = 1 - nl;
            if (nl) xfprintf(fp, "\n");
         }
         if (!nl) xfprintf(fp, "\n");
      }
      /* write BOUNDS section */
      flag = 0;
      {  strcpy(vname, frei ? "" : "BND1");
         for (j = 1; j <= ncols; j++)
         {  int typx;
            double lb, ub;
            lpx_get_col_bnds(lp, j, &typx, &lb, &ub);
            if (typx == LPX_LO && lb == 0.0) continue;
            if (!flag) xfprintf(fp, "BOUNDS\n"), flag = 1;
            switch (typx)
            {  case LPX_FR:
                  xfprintf(fp, " FR %-8s  %-8s\n", vname,
                     col_name(lp, j, cname));
                  break;
               case LPX_LO:
                  xfprintf(fp, " LO %-8s  %-8s  %12s\n", vname,
                     col_name(lp, j, cname), mps_numb(lb, numb));
                  break;
               case LPX_UP:
                  xfprintf(fp, " MI %-8s  %-8s\n", vname,
                     col_name(lp, j, cname));
                  xfprintf(fp, " UP %-8s  %-8s  %12s\n", vname,
                     col_name(lp, j, cname), mps_numb(ub, numb));
                  break;
               case LPX_DB:
                  if (lb != 0.0)
                  xfprintf(fp, " LO %-8s  %-8s  %12s\n", vname,
                     col_name(lp, j, cname), mps_numb(lb, numb));
                  xfprintf(fp, " UP %-8s  %-8s  %12s\n", vname,
                     col_name(lp, j, cname), mps_numb(ub, numb));
                  break;
               case LPX_FX:
                  xfprintf(fp, " FX %-8s  %-8s  %12s\n", vname,
                     col_name(lp, j, cname), mps_numb(lb, numb));
                  break;
               default:
                  xassert(typx != typx);
            }
         }
      }
      /* write ENDATA indicator card */
      xfprintf(fp, "ENDATA\n");
      /* close the output text file */
      xfflush(fp);
      if (xferror(fp))
      {  xprintf("glp_write_mps: write error on `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      xfclose(fp);
      /* return to the calling program */
      return 0;
fail: /* the operation failed */
      if (fp != NULL) xfclose(fp);
      return 1;
}

/*----------------------------------------------------------------------
-- read_bas - read LP basis in fixed MPS format.
--
-- *Synopsis*
--
-- #include "glpmps.h"
-- int read_bas(LPX *lp, char *fname);
--
-- *Description*
--
-- The routine read_bas reads LP basis in fixed MPS format from an
-- input text file whose name is the character string fname.
--
-- *Returns*
--
-- If the operation was successful, the routine returns zero. Otherwise
-- the routine prints an error message and returns non-zero. */

int read_bas(LPX *lp, const char *fname)
{     struct dsa _dsa, *dsa = &_dsa;
      int i, j;
      dsa->lp = lp;
      dsa->fname = fname;
      dsa->fp = NULL;
      dsa->count = 0;
      dsa->obj = 0;
      xprintf("lpx_read_bas: reading LP basis from `%s'...\n",
         dsa->fname);
      dsa->fp = xfopen(dsa->fname, "r");
      if (dsa->fp == NULL)
      {  xprintf("lpx_read_bas: unable to open `%s' - %s\n",
            dsa->fname, strerror(errno));
         goto fail;
      }
      lpx_create_index(dsa->lp);
      /* read NAME indicator card */
      if (read_card(dsa)) goto fail;
      if (memcmp(dsa->card, "NAME ", 5) != 0)
      {  xprintf("%s:%d: NAME indicator card missing\n", dsa->fname,
            dsa->count);
         goto fail;
      }
      /* build the "standard" basis of all slacks */
      lpx_std_basis(dsa->lp);
loop: /* read and split next data card */
      if (read_card(dsa)) goto fail;
      if (dsa->card[0] != ' ') goto fini;
      if (split_card(dsa)) goto fail;
      /* check indicator in field 1 */
      if (!(strcmp(dsa->f1, "XL") == 0 || strcmp(dsa->f1, "XU") == 0 ||
            strcmp(dsa->f1, "LL") == 0 || strcmp(dsa->f1, "UL") == 0))
      {  xprintf("%s:%d: invalid indicator in field 1\n", dsa->fname,
            dsa->count);
         goto fail;
      }
      /* scan column name in field 2 */
      if (dsa->f2[0] == '\0')
      {  xprintf("%s:%d: missing column name in field 2\n", dsa->fname,
            dsa->count);
         goto fail;
      }
      j = lpx_find_col(dsa->lp, dsa->f2);
      if (j == 0)
      {  xprintf("%s:%d: column %s not found\n", dsa->fname, dsa->count,
            dsa->f2);
         goto fail;
      }
      /* process field 3 */
      if (dsa->f1[0] == 'X')
      {  /* scan row name in field 3 */
         if (dsa->f3[0] == '\0')
         {  xprintf("%s:%d: missing row name in field 3\n", dsa->fname,
               dsa->count);
            goto fail;
         }
         i = lpx_find_row(dsa->lp, dsa->f3);
         if (i == 0)
         {  xprintf("%s:%d: row %s not found\n", dsa->fname, dsa->count,
               dsa->f3);
            goto fail;
         }
      }
      else
      {  /* field 3 must be blank */
         if (dsa->f3[0] != '\0')
         {  xprintf("%s:%d: invalid data card; field 3 must be blank\n",
               dsa->fname, dsa->count);
            goto fail;
         }
         i = 0;
      }
      /* fields 4-6 must be blank */
      if (!(dsa->f4[0] == '\0' && dsa->f5[0] == '\0' &&
            dsa->f6[0] == '\0'))
      {  xprintf("%s:%d: invalid data card; fields 4-6 must be blank\n",
            dsa->fname, dsa->count);
         goto fail;
      }
      /* apply a "patch" */
      if (dsa->f1[0] == 'X')
      {  lpx_set_row_stat(dsa->lp, i, dsa->f1[1] == 'L' ? LPX_NL :
            LPX_NU);
         lpx_set_col_stat(dsa->lp, j, LPX_BS);
      }
      else
         lpx_set_col_stat(dsa->lp, j, dsa->f1[0] == 'L' ? LPX_NL :
            LPX_NU);
      goto loop;
fini: /* check ENDATA indicator card */
      if (memcmp(dsa->card, "ENDATA ", 7) != 0)
      {  xprintf("%s:%d: ENDATA indicator card missing\n", dsa->fname,
            dsa->count);
         goto fail;
      }
      xprintf("lpx_read_bas: %d cards were read\n", dsa->count);
      xfclose(dsa->fp);
      lpx_delete_index(dsa->lp);
      return 0;
fail: if (dsa->fp != NULL) xfclose(dsa->fp);
      lpx_delete_index(dsa->lp);
      return 1;
}

/*----------------------------------------------------------------------
-- write_bas - write LP basis in fixed MPS format.
--
-- *Synopsis*
--
-- #include "glpmps.h"
-- int write_bas(LPX *lp, char *fname);
--
-- *Description*
--
-- The routine write_bas writes current LP basis in fixed MPS format to
-- an output text file whose name is the character string fname.
--
-- *Returns*
--
-- If the operation was successful, the routine returns zero. Otherwise
-- the routine prints an error message and returns non-zero. */

int write_bas(LPX *lp, const char *fname)
{     XFILE *fp;
      int nrows, ncols, i, j, rtype, ctype, rstat, cstat;
      char rname[8+1], cname[8+1];
      xprintf("lpx_write_bas: writing LP basis to `%s'...\n", fname);
      /* open the output text file */
      fp = xfopen(fname, "w");
      if (fp == NULL)
      {  xprintf("lpx_write_bas: unable to create `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      /* determine number of rows and number of columns */
      nrows = lpx_get_num_rows(lp);
      ncols = lpx_get_num_cols(lp);
      /* the problem should contain at least one row and one column */
      if (!(nrows > 0 && ncols > 0))
         xerror("lpx_write_bas: problem has no rows/columns\n");
      /* write comment cards (if required) */
      if (lpx_get_int_parm(lp, LPX_K_MPSINFO))
      {  int dir, status;
         double obj;
         const char *name;
         /* problem name and statistics */
         name = lpx_get_prob_name(lp);
         if (name == NULL) name = "UNKNOWN";
         xfprintf(fp, "* Problem:    %.31s\n", name);
         xfprintf(fp, "* Rows:       %d\n", nrows);
         xfprintf(fp, "* Columns:    %d\n", ncols);
         xfprintf(fp, "* Non-zeros:  %d\n", lpx_get_num_nz(lp));
         /* solution status */
         status = lpx_get_status(lp);
         xfprintf(fp, "* Status:     %s\n",
            status == LPX_OPT    ? "OPTIMAL" :
            status == LPX_FEAS   ? "FEASIBLE" :
            status == LPX_INFEAS ? "INFEASIBLE (INTERMEDIATE)" :
            status == LPX_NOFEAS ? "INFEASIBLE (FINAL)" :
            status == LPX_UNBND  ? "UNBOUNDED" :
            status == LPX_UNDEF  ? "UNDEFINED" : "???");
         /* objective function */
         name = lpx_get_obj_name(lp);
         dir = lpx_get_obj_dir(lp);
         obj = lpx_get_obj_val(lp);
         xfprintf(fp, "* Objective:  %s%s%.10g %s\n",
            name == NULL ? "" : name,
            name == NULL ? "" : " = ", obj,
            dir == LPX_MIN ? "(MINimum)" :
            dir == LPX_MAX ? "(MAXimum)" : "(" "???" ")");
         xfprintf(fp, "* Format:     Fixed MPS\n");
         xfprintf(fp, "*\n");
      }
      /* write NAME indicator card */
      {  const char *name = lpx_get_prob_name(lp);
         if (name == NULL)
            xfprintf(fp, "NAME\n");
         else
            xfprintf(fp, "NAME          %.8s\n", name);
      }
      /* write information about which columns should be made basic
         and which rows should be made non-basic */
      i = j = 0;
      for (;;)
      {  /* find a next non-basic row */
         for (i++; i <= nrows; i++)
         {  lpx_get_row_info(lp, i, &rstat, NULL, NULL);
            if (rstat != LPX_BS) break;
         }
         /* find a next basic column */
         for (j++; j <= ncols; j++)
         {  lpx_get_col_info(lp, j, &cstat, NULL, NULL);
            if (cstat == LPX_BS) break;
         }
         /* if all non-basic rows and basic columns have been written,
            break the loop */
         if (i > nrows && j > ncols) break;
         /* since the basis is valid, there must be nor extra non-basic
            rows nor extra basic columns */
         xassert(i <= nrows && j <= ncols);
         /* write the pair (basic column, non-basic row) */
         lpx_get_row_bnds(lp, i, &rtype, NULL, NULL);
         xfprintf(fp, " %s %-8s  %s\n",
            (rtype == LPX_DB && rstat == LPX_NU) ? "XU" : "XL",
            col_name(lp, j, cname), row_name(lp, i, rname));
      }
      /* write information about statuses of double-bounded non-basic
         columns */
      for (j = 1; j <= ncols; j++)
      {  lpx_get_col_bnds(lp, j, &ctype, NULL, NULL);
         lpx_get_col_info(lp, j, &cstat, NULL, NULL);
         if (ctype == LPX_DB && cstat != LPX_BS)
            xfprintf(fp, " %s %s\n",
               cstat == LPX_NU ? "UL" : "LL", col_name(lp, j, cname));
      }
      /* write ENDATA indcator card */
      xfprintf(fp, "ENDATA\n");
      /* close the output text file */
      xfflush(fp);
      if (xferror(fp))
      {  xprintf("lpx_write_bas: write error on `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      xfclose(fp);
      /* return to the calling program */
      return 0;
fail: /* the operation failed */
      if (fp != NULL) xfclose(fp);
      return 1;
}

/* eof */