Beispiel #1
0
int CClp_opt(CClp *lp, int method)
{     /* CALLS designated LP solution method. */
      int stat, ret;
      if (MSGLEV >= 1)
      {  int m = lpx_get_num_rows(lp->lp);
         int n = lpx_get_num_cols(lp->lp);
         int nz = lpx_get_num_nz(lp->lp);
         print("CClp_opt: %-11s m = %d; n = %d; nz = %d",
            method == CClp_METHOD_DUAL ? "(dual)" : "(primal)",
            m, n, nz);
      }
      lpx_set_int_parm(lp->lp, LPX_K_DUAL, method == CClp_METHOD_DUAL);
      switch (MSGLEV)
      {  case 0:
            lpx_set_int_parm(lp->lp, LPX_K_MSGLEV, 0);
            lpx_set_int_parm(lp->lp, LPX_K_OUTFRQ, 1000000);
            lpx_set_real_parm(lp->lp, LPX_K_OUTDLY, 1e6);
            break;
         case 1:
            lpx_set_int_parm(lp->lp, LPX_K_MSGLEV, 2);
            lpx_set_int_parm(lp->lp, LPX_K_OUTFRQ, 200);
            lpx_set_real_parm(lp->lp, LPX_K_OUTDLY, 5.0);
            break;
         case 2:
            lpx_set_int_parm(lp->lp, LPX_K_MSGLEV, 3);
            lpx_set_int_parm(lp->lp, LPX_K_OUTFRQ, 200);
            lpx_set_real_parm(lp->lp, LPX_K_OUTDLY, 0.0);
            break;
         default:
            insist(MSGLEV != MSGLEV);
      }
      ret = lpx_simplex(lp->lp);
      if (ret == LPX_E_FAULT)
      {  if (MSGLEV >= 1) print("CClp_opt: restarting from advanced bas"
            "is...");
         lpx_adv_basis(lp->lp);
         ret = lpx_simplex(lp->lp);
      }
      if (ret != LPX_E_OK)
      {  print("CClp_opt: lpx_simplex failed; return code = %d", ret);
         ret = 1;
         goto done;
      }
      stat = lpx_get_status(lp->lp);
      if (stat == LPX_OPT)
         ret = 0;
      else if (stat == LPX_NOFEAS)
         ret = 2;
      else
      {  print("CClp_opt: optimization status = %d", stat);
         ret = 1;
      }
done: return ret;
}
Beispiel #2
0
static void show_status(LPX *prob, int prob_m, int prob_nz)
{     int n, j, count;
      double x, tol_int;
      /* determine the number of structural variables of integer kind
         whose current values are still fractional */
      n = lpx_get_num_cols(prob);
      tol_int = lpx_get_real_parm(prob, LPX_K_TOLINT);
      count = 0;
      for (j = 1; j <= n; j++)
      {  if (lpx_get_col_kind(prob, j) != LPX_IV) continue;
         x = lpx_get_col_prim(prob, j);
         if (fabs(x - floor(x + 0.5)) <= tol_int) continue;
         count++;
      }
      print("&%6d: obj = %17.9e   frac = %5d   cuts = %5d (%d)",
         lpx_get_int_parm(prob, LPX_K_ITCNT),
         lpx_get_obj_val(prob), count,
         lpx_get_num_rows(prob) - prob_m,
         lpx_get_num_nz(prob) - prob_nz);
      return;
}
Beispiel #3
0
LPX *lpp_build_prob(LPP *lpp)
{     LPX *prob;
      LPPROW *row;
      LPPCOL *col;
      struct load_info info;
      int i, j, typx;
      /* count number of rows and columns in the resultant problem */
      lpp->m = lpp->n = 0;
      for (row = lpp->row_ptr; row != NULL; row = row->next) lpp->m++;
      for (col = lpp->col_ptr; col != NULL; col = col->next) lpp->n++;
      /* allocate two arrays to save reference numbers assigned to rows
         and columns of the resultant problem */
      lpp->row_ref = ucalloc(1+lpp->m, sizeof(int));
      lpp->col_ref = ucalloc(1+lpp->n, sizeof(int));
      /* create LP problem object */
      prob = lpx_create_prob();
      /* the resultant problem should have the same optimization sense
         as the original problem */
      lpx_set_obj_dir(prob, lpp->orig_dir);
      /* set the constant term of the objective function */
      lpx_set_obj_c0(prob,
         lpp->orig_dir == LPX_MIN ? + lpp->c0 : - lpp->c0);
      /* create rows of the resultant problem */
      insist(lpp->m > 0);
      lpx_add_rows(prob, lpp->m);
      for (i = 1, row = lpp->row_ptr; i <= lpp->m; i++, row = row->next)
      {  insist(row != NULL);
         lpp->row_ref[i] = row->i;
         row->i = i;
         if (row->lb == -DBL_MAX && row->ub == +DBL_MAX)
            typx = LPX_FR;
         else if (row->ub == +DBL_MAX)
            typx = LPX_LO;
         else if (row->lb == -DBL_MAX)
            typx = LPX_UP;
         else if (row->lb != row->ub)
            typx = LPX_DB;
         else
            typx = LPX_FX;
         lpx_set_row_bnds(prob, i, typx, row->lb, row->ub);
      }
      insist(row == NULL);
      /* create columns of the resultant problem */
      insist(lpp->n > 0);
      lpx_add_cols(prob, lpp->n);
      for (j = 1, col = lpp->col_ptr; j <= lpp->n; j++, col = col->next)
      {  insist(col != NULL);
         lpp->col_ref[j] = col->j;
         col->j = j;
         if (col->lb == -DBL_MAX && col->ub == +DBL_MAX)
            typx = LPX_FR;
         else if (col->ub == +DBL_MAX)
            typx = LPX_LO;
         else if (col->lb == -DBL_MAX)
            typx = LPX_UP;
         else if (col->lb != col->ub)
            typx = LPX_DB;
         else
            typx = LPX_FX;
         lpx_set_col_bnds(prob, j, typx, col->lb, col->ub);
         lpx_set_col_coef(prob, j,
            lpp->orig_dir == LPX_MIN ? + col->c : - col->c);
      }
      insist(col == NULL);
      /* create the constraint matrix of the resultant problem */
      info.lpp = lpp;
      info.row = NULL;
      info.aij = NULL;
      lpx_load_mat(prob, &info, next_aij);
      /* count number of non-zeros in the resultant problem */
      lpp->nnz = lpx_get_num_nz(prob);
      /* internal data structures that represnts the resultant problem
         are no longer needed, so free them */
      dmp_delete_pool(lpp->row_pool), lpp->row_pool = NULL;
      dmp_delete_pool(lpp->col_pool), lpp->col_pool = NULL;
      dmp_delete_pool(lpp->aij_pool), lpp->aij_pool = NULL;
      lpp->row_ptr = NULL, lpp->col_ptr = NULL;
      lpp->row_que = NULL, lpp->col_que = NULL;
      /* return a pointer to the built LP problem object */
      return prob;
}
Beispiel #4
0
void lpp_load_orig(LPP *lpp, LPX *orig)
{     LPPROW *row;
      LPPCOL *col, **map;
      int i, j, t, len, typx, *ndx;
      double lb, ub, temp, *c, *val;
      /* save some information about the original problem */
      lpp->orig_m = lpx_get_num_rows(orig);
      lpp->orig_n = lpx_get_num_cols(orig);
      lpp->orig_nnz = lpx_get_num_nz(orig);
      lpp->orig_dir = lpx_get_obj_dir(orig);
      /* allocate working arrays */
      c = ucalloc(1+lpp->orig_n, sizeof(double));
      ndx = ucalloc(1+lpp->orig_n, sizeof(int));
      val = ucalloc(1+lpp->orig_n, sizeof(double));
      /* auxiliary variables (i.e. rows) in the original problem may
         have non-zero objective coefficients; so, we substitute these
         auxiliary variables into the objective function in order that
         it depends only on structural variables (i.e. columns); the
         resultant vector of objective coefficients is accumulated in
         the working array c */
      for (j = 1; j <= lpp->orig_n; j++)
         c[j] = lpx_get_col_coef(orig, j);
      for (i = 1; i <= lpp->orig_m; i++)
      {  /* obtain an objective coefficient at i-th row */
         temp = lpx_get_row_coef(orig, i);
         /* substitute i-th row into the objective function */
         if (temp != 0.0)
         {  len = lpx_get_mat_row(orig, i, ndx, val);
            for (t = 1; t <= len; t++) c[ndx[t]] += val[t] * temp;
         }
      }
      /* copy rows of the original problem into the workspace; each
         row created in the workspace is assigned a reference number,
         which is its ordinal number in the original problem */
      for (i = 1; i <= lpp->orig_m; i++)
      {  lpx_get_row_bnds(orig, i, &typx, &lb, &ub);
         if (typx == LPX_FR || typx == LPX_UP) lb = -DBL_MAX;
         if (typx == LPX_FR || typx == LPX_LO) ub = +DBL_MAX;
         if (typx == LPX_FX) ub = lb;
         lpp_add_row(lpp, lb, ub);
      }
      /* copy columns of the original problem into the workspace; each
         column created in the workspace is assigned a reference number,
         which its ordinal number in the original problem */
      for (j = 1; j <= lpp->orig_n; j++)
      {  lpx_get_col_bnds(orig, j, &typx, &lb, &ub);
         if (typx == LPX_FR || typx == LPX_UP) lb = -DBL_MAX;
         if (typx == LPX_FR || typx == LPX_LO) ub = +DBL_MAX;
         if (typx == LPX_FX) ub = lb;
         lpp_add_col(lpp, lb, ub, c[j]);
      }
      /* copy the constant term of the original objective function */
      lpp->c0 = lpx_get_obj_c0(orig);
      /* if the original problem is maximization, change the sign of
         the objective function, because the transformed problem to be
         processed by the presolver must be minimization */
      if (lpp->orig_dir == LPX_MAX)
      {  for (col = lpp->col_ptr; col != NULL; col = col->next)
            col->c = - col->c;
         lpp->c0 = - lpp->c0;
      }
      /* build an auxiliary array to map column ordinal numbers to the
         corresponding pointers */
      insist(sizeof(LPPCOL *) <= sizeof(double));
      map = (LPPCOL **)c;
      for (col = lpp->col_ptr; col != NULL; col = col->next)
         map[col->j] = col;
      /* copy the original constraint matrix into the workspace */
      for (row = lpp->row_ptr; row != NULL; row = row->next)
#if 1
      {  len = lpx_get_mat_row(orig, row->i, ndx, val);
         for (t = 1; t <= len; t++)
            lpp_add_aij(lpp, row, map[ndx[t]], val[t]);
      }
#else /* 27/XI-2003 (the problem persists) */
      {  double big, eps;
         len = lpx_get_mat_row(orig, row->i, ndx, val);
         big = 0.0;
         for (t = 1; t <= len; t++)
            if (big < fabs(val[t])) big = fabs(val[t]);
         eps = 1e-10 * big;
         for (t = 1; t <= len; t++)
         {  if (fabs(val[t]) < eps) continue;
            lpp_add_aij(lpp, row, map[ndx[t]], val[t]);
         }
      }
#endif
      /* free working arrays */
      ufree(c);
      ufree(ndx);
      ufree(val);
      return;
}
Beispiel #5
0
LPX *lpx_read_cpxlp(const char *fname)
{     /* read problem data in CPLEX LP format */
      struct dsa _dsa, *dsa = &_dsa;
      if (setjmp(dsa->jump)) goto fail;
      dsa->lp = NULL;
      dsa->fname = fname;
      dsa->fp = NULL;
      dsa->count = 0;
      dsa->c = '\n';
      dsa->token = T_EOF;
      dsa->image[0] = '\0';
      dsa->imlen = 0;
      dsa->value = 0.0;
      dsa->n_max = 100;
      dsa->map = xcalloc(1+dsa->n_max, sizeof(int));
      memset(&dsa->map[1], 0, dsa->n_max * sizeof(int));
      dsa->ind = xcalloc(1+dsa->n_max, sizeof(int));
      dsa->val = xcalloc(1+dsa->n_max, sizeof(double));
      dsa->lb = xcalloc(1+dsa->n_max, sizeof(double));
      dsa->ub = xcalloc(1+dsa->n_max, sizeof(double));
      print("lpx_read_cpxlp: reading problem data from `%s'...",
         dsa->fname);
      dsa->fp = xfopen(dsa->fname, "r");
      if (dsa->fp == NULL)
      {  print("lpx_read_cpxlp: unable to open `%s' - %s", dsa->fname,
            strerror(errno));
         goto fail;
      }
      dsa->lp = lpx_create_prob();
      lpx_create_index(dsa->lp);
#if 0
      /* read very first character */
      read_char(dsa);
#endif
      /* scan very first token */
      scan_token(dsa);
      /* parse definition of the objective function */
      if (!(dsa->token == T_MINIMIZE || dsa->token == T_MAXIMIZE))
         fatal(dsa, "`minimize' or `maximize' keyword missing");
      parse_objective(dsa);
      /* parse constraints section */
      if (dsa->token != T_SUBJECT_TO)
         fatal(dsa, "constraints section missing");
      parse_constraints(dsa);
      /* parse optional bounds section */
      if (dsa->token == T_BOUNDS) parse_bounds(dsa);
      /* parse optional general, integer, and binary sections */
      while (dsa->token == T_GENERAL ||
             dsa->token == T_INTEGER ||
             dsa->token == T_BINARY) parse_integer(dsa);
      /* check for the keyword 'end' */
      if (dsa->token == T_END)
         scan_token(dsa);
      else if (dsa->token == T_EOF)
         print("%s:%d: warning: keyword `end' missing", dsa->fname,
            dsa->count);
      else
         fatal(dsa, "symbol `%s' in wrong position", dsa->image);
      /* nothing must follow the keyword 'end' (except comments) */
      if (dsa->token != T_EOF)
         fatal(dsa, "extra symbol(s) detected beyond `end'");
      /* set bounds of variables */
      {  int j, type;
         double lb, ub;
         for (j = lpx_get_num_cols(dsa->lp); j >= 1; j--)
         {  lb = dsa->lb[j];
            ub = dsa->ub[j];
            if (lb == +DBL_MAX) lb = 0.0;      /* default lb */
            if (ub == -DBL_MAX) ub = +DBL_MAX; /* default ub */
            if (lb == -DBL_MAX && ub == +DBL_MAX)
               type = LPX_FR;
            else if (ub == +DBL_MAX)
               type = LPX_LO;
            else if (lb == -DBL_MAX)
               type = LPX_UP;
            else if (lb != ub)
               type = LPX_DB;
            else
               type = LPX_FX;
            lpx_set_col_bnds(dsa->lp, j, type, lb, ub);
         }
      }
      /* print some statistics */
      {  int m = lpx_get_num_rows(dsa->lp);
         int n = lpx_get_num_cols(dsa->lp);
         int nnz = lpx_get_num_nz(dsa->lp);
         print("lpx_read_cpxlp: %d row%s, %d column%s, %d non-zero%s",
            m, m == 1 ? "" : "s", n, n == 1 ? "" : "s", nnz, nnz == 1 ?
            "" : "s");
      }
      if (lpx_get_class(dsa->lp) == LPX_MIP)
      {  int ni = lpx_get_num_int(dsa->lp);
         int nb = lpx_get_num_bin(dsa->lp);
         char s[50];
         if (nb == 0)
            strcpy(s, "none of");
         else if (ni == 1 && nb == 1)
            strcpy(s, "");
         else if (nb == 1)
            strcpy(s, "one of");
         else if (nb == ni)
            strcpy(s, "all of");
         else
            sprintf(s, "%d of", nb);
         print("lpx_read_cpxlp: %d integer column%s, %s which %s binary"
            , ni, ni == 1 ? "" : "s", s, nb == 1 ? "is" : "are");
      }
      print("lpx_read_cpxlp: %d lines were read", dsa->count);
      xfclose(dsa->fp);
      xfree(dsa->map);
      xfree(dsa->ind);
      xfree(dsa->val);
      xfree(dsa->lb);
      xfree(dsa->ub);
      lpx_delete_index(dsa->lp);
      lpx_order_matrix(dsa->lp);
      return dsa->lp;
fail: if (dsa->lp != NULL) lpx_delete_prob(dsa->lp);
      if (dsa->fp != NULL) xfclose(dsa->fp);
      if (dsa->map != NULL) xfree(dsa->map);
      if (dsa->ind != NULL) xfree(dsa->ind);
      if (dsa->val != NULL) xfree(dsa->val);
      if (dsa->lb != NULL) xfree(dsa->lb);
      if (dsa->ub != NULL) xfree(dsa->ub);
      return NULL;
}
int lpx_print_prob(LPX *lp, const char *fname)
{     XFILE *fp;
      int m, n, mip, i, j, len, t, type, *ndx;
      double coef, lb, ub, *val;
      char *str, name[255+1];
      xprintf("lpx_write_prob: writing problem data to `%s'...\n",
         fname);
      fp = xfopen(fname, "w");
      if (fp == NULL)
      {  xprintf("lpx_write_prob: unable to create `%s' - %s\n",
            fname, strerror(errno));
         goto fail;
      }
      m = lpx_get_num_rows(lp);
      n = lpx_get_num_cols(lp);
      mip = (lpx_get_class(lp) == LPX_MIP);
      str = (void *)lpx_get_prob_name(lp);
      xfprintf(fp, "Problem:    %s\n", str == NULL ? "(unnamed)" : str);
      xfprintf(fp, "Class:      %s\n", !mip ? "LP" : "MIP");
      xfprintf(fp, "Rows:       %d\n", m);
      if (!mip)
         xfprintf(fp, "Columns:    %d\n", n);
      else
         xfprintf(fp, "Columns:    %d (%d integer, %d binary)\n",
            n, lpx_get_num_int(lp), lpx_get_num_bin(lp));
      xfprintf(fp, "Non-zeros:  %d\n", lpx_get_num_nz(lp));
      xfprintf(fp, "\n");
      xfprintf(fp, "*** OBJECTIVE FUNCTION ***\n");
      xfprintf(fp, "\n");
      switch (lpx_get_obj_dir(lp))
      {  case LPX_MIN:
            xfprintf(fp, "Minimize:");
            break;
         case LPX_MAX:
            xfprintf(fp, "Maximize:");
            break;
         default:
            xassert(lp != lp);
      }
      str = (void *)lpx_get_obj_name(lp);
      xfprintf(fp, " %s\n", str == NULL ? "(unnamed)" : str);
      coef = lpx_get_obj_coef(lp, 0);
      if (coef != 0.0)
         xfprintf(fp, "%*.*g %s\n", DBL_DIG+7, DBL_DIG, coef,
            "(constant term)");
      for (i = 1; i <= m; i++)
#if 0
      {  coef = lpx_get_row_coef(lp, i);
#else
      {  coef = 0.0;
#endif
         if (coef != 0.0)
            xfprintf(fp, "%*.*g %s\n", DBL_DIG+7, DBL_DIG, coef,
               row_name(lp, i, name));
      }
      for (j = 1; j <= n; j++)
      {  coef = lpx_get_obj_coef(lp, j);
         if (coef != 0.0)
            xfprintf(fp, "%*.*g %s\n", DBL_DIG+7, DBL_DIG, coef,
               col_name(lp, j, name));
      }
      xfprintf(fp, "\n");
      xfprintf(fp, "*** ROWS (CONSTRAINTS) ***\n");
      ndx = xcalloc(1+n, sizeof(int));
      val = xcalloc(1+n, sizeof(double));
      for (i = 1; i <= m; i++)
      {  xfprintf(fp, "\n");
         xfprintf(fp, "Row %d: %s", i, row_name(lp, i, name));
         lpx_get_row_bnds(lp, i, &type, &lb, &ub);
         switch (type)
         {  case LPX_FR:
               xfprintf(fp, " free");
               break;
            case LPX_LO:
               xfprintf(fp, " >= %.*g", DBL_DIG, lb);
               break;
            case LPX_UP:
               xfprintf(fp, " <= %.*g", DBL_DIG, ub);
               break;
            case LPX_DB:
               xfprintf(fp, " >= %.*g <= %.*g", DBL_DIG, lb, DBL_DIG,
                  ub);
               break;
            case LPX_FX:
               xfprintf(fp, " = %.*g", DBL_DIG, lb);
               break;
            default:
               xassert(type != type);
         }
         xfprintf(fp, "\n");
#if 0
         coef = lpx_get_row_coef(lp, i);
#else
         coef = 0.0;
#endif
         if (coef != 0.0)
            xfprintf(fp, "%*.*g %s\n", DBL_DIG+7, DBL_DIG, coef,
               "(objective)");
         len = lpx_get_mat_row(lp, i, ndx, val);
         for (t = 1; t <= len; t++)
            xfprintf(fp, "%*.*g %s\n", DBL_DIG+7, DBL_DIG, val[t],
               col_name(lp, ndx[t], name));
      }
      xfree(ndx);
      xfree(val);
      xfprintf(fp, "\n");
      xfprintf(fp, "*** COLUMNS (VARIABLES) ***\n");
      ndx = xcalloc(1+m, sizeof(int));
      val = xcalloc(1+m, sizeof(double));
      for (j = 1; j <= n; j++)
      {  xfprintf(fp, "\n");
         xfprintf(fp, "Col %d: %s", j, col_name(lp, j, name));
         if (mip)
         {  switch (lpx_get_col_kind(lp, j))
            {  case LPX_CV:
                  break;
               case LPX_IV:
                  xfprintf(fp, " integer");
                  break;
               default:
                  xassert(lp != lp);
            }
         }
         lpx_get_col_bnds(lp, j, &type, &lb, &ub);
         switch (type)
         {  case LPX_FR:
               xfprintf(fp, " free");
               break;
            case LPX_LO:
               xfprintf(fp, " >= %.*g", DBL_DIG, lb);
               break;
            case LPX_UP:
               xfprintf(fp, " <= %.*g", DBL_DIG, ub);
               break;
            case LPX_DB:
               xfprintf(fp, " >= %.*g <= %.*g", DBL_DIG, lb, DBL_DIG,
                  ub);
               break;
            case LPX_FX:
               xfprintf(fp, " = %.*g", DBL_DIG, lb);
               break;
            default:
               xassert(type != type);
         }
         xfprintf(fp, "\n");
         coef = lpx_get_obj_coef(lp, j);
         if (coef != 0.0)
            xfprintf(fp, "%*.*g %s\n", DBL_DIG+7, DBL_DIG, coef,
               "(objective)");
         len = lpx_get_mat_col(lp, j, ndx, val);
         for (t = 1; t <= len; t++)
            xfprintf(fp, "%*.*g %s\n", DBL_DIG+7, DBL_DIG, val[t],
               row_name(lp, ndx[t], name));
      }
      xfree(ndx);
      xfree(val);
      xfprintf(fp, "\n");
      xfprintf(fp, "End of output\n");
      xfflush(fp);
      if (xferror(fp))
      {  xprintf("lpx_write_prob: write error on `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      xfclose(fp);
      return 0;
fail: if (fp != NULL) xfclose(fp);
      return 1;
}

#undef row_name
#undef col_name

/*----------------------------------------------------------------------
-- lpx_print_sol - write LP problem solution in printable format.
--
-- *Synopsis*
--
-- #include "glplpx.h"
-- int lpx_print_sol(LPX *lp, char *fname);
--
-- *Description*
--
-- The routine lpx_print_sol writes the current basic solution of an LP
-- problem, which is specified by the pointer lp, to a text file, whose
-- name is the character string fname, in printable format.
--
-- Information reported by the routine lpx_print_sol is intended mainly
-- for visual analysis.
--
-- *Returns*
--
-- If the operation was successful, the routine returns zero. Otherwise
-- the routine prints an error message and returns non-zero. */

int lpx_print_sol(LPX *lp, const char *fname)
{     XFILE *fp;
      int what, round;
      xprintf(
         "lpx_print_sol: writing LP problem solution to `%s'...\n",
         fname);
      fp = xfopen(fname, "w");
      if (fp == NULL)
      {  xprintf("lpx_print_sol: can't create `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      /* problem name */
      {  const char *name;
         name = lpx_get_prob_name(lp);
         if (name == NULL) name = "";
         xfprintf(fp, "%-12s%s\n", "Problem:", name);
      }
      /* number of rows (auxiliary variables) */
      {  int nr;
         nr = lpx_get_num_rows(lp);
         xfprintf(fp, "%-12s%d\n", "Rows:", nr);
      }
      /* number of columns (structural variables) */
      {  int nc;
         nc = lpx_get_num_cols(lp);
         xfprintf(fp, "%-12s%d\n", "Columns:", nc);
      }
      /* number of non-zeros (constraint coefficients) */
      {  int nz;
         nz = lpx_get_num_nz(lp);
         xfprintf(fp, "%-12s%d\n", "Non-zeros:", nz);
      }
      /* solution status */
      {  int status;
         status = lpx_get_status(lp);
         xfprintf(fp, "%-12s%s\n", "Status:",
            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 */
      {  char *name;
         int dir;
         double obj;
         name = (void *)lpx_get_obj_name(lp);
         dir = lpx_get_obj_dir(lp);
         obj = lpx_get_obj_val(lp);
         xfprintf(fp, "%-12s%s%s%.10g %s\n", "Objective:",
            name == NULL ? "" : name,
            name == NULL ? "" : " = ", obj,
            dir == LPX_MIN ? "(MINimum)" :
            dir == LPX_MAX ? "(MAXimum)" : "(" "???" ")");
      }
      /* main sheet */
      for (what = 1; what <= 2; what++)
      {  int mn, ij;
         xfprintf(fp, "\n");
         xfprintf(fp, "   No. %-12s St   Activity     Lower bound   Upp"
            "er bound    Marginal\n",
            what == 1 ? "  Row name" : "Column name");
         xfprintf(fp, "------ ------------ -- ------------- -----------"
            "-- ------------- -------------\n");
         mn = (what == 1 ? lpx_get_num_rows(lp) : lpx_get_num_cols(lp));
         for (ij = 1; ij <= mn; ij++)
         {  const char *name;
            int typx, tagx;
            double lb, ub, vx, dx;
            if (what == 1)
            {  name = lpx_get_row_name(lp, ij);
               if (name == NULL) name = "";
               lpx_get_row_bnds(lp, ij, &typx, &lb, &ub);
               round = lpx_get_int_parm(lp, LPX_K_ROUND);
               lpx_set_int_parm(lp, LPX_K_ROUND, 1);
               lpx_get_row_info(lp, ij, &tagx, &vx, &dx);
               lpx_set_int_parm(lp, LPX_K_ROUND, round);
            }
            else
            {  name = lpx_get_col_name(lp, ij);
               if (name == NULL) name = "";
               lpx_get_col_bnds(lp, ij, &typx, &lb, &ub);
               round = lpx_get_int_parm(lp, LPX_K_ROUND);
               lpx_set_int_parm(lp, LPX_K_ROUND, 1);
               lpx_get_col_info(lp, ij, &tagx, &vx, &dx);
               lpx_set_int_parm(lp, LPX_K_ROUND, round);
            }
            /* row/column ordinal number */
            xfprintf(fp, "%6d ", ij);
            /* row column/name */
            if (strlen(name) <= 12)
               xfprintf(fp, "%-12s ", name);
            else
               xfprintf(fp, "%s\n%20s", name, "");
            /* row/column status */
            xfprintf(fp, "%s ",
               tagx == LPX_BS ? "B " :
               tagx == LPX_NL ? "NL" :
               tagx == LPX_NU ? "NU" :
               tagx == LPX_NF ? "NF" :
               tagx == LPX_NS ? "NS" : "??");
            /* row/column primal activity */
            xfprintf(fp, "%13.6g ", vx);
            /* row/column lower bound */
            if (typx == LPX_LO || typx == LPX_DB || typx == LPX_FX)
               xfprintf(fp, "%13.6g ", lb);
            else
               xfprintf(fp, "%13s ", "");
            /* row/column upper bound */
            if (typx == LPX_UP || typx == LPX_DB)
               xfprintf(fp, "%13.6g ", ub);
            else if (typx == LPX_FX)
               xfprintf(fp, "%13s ", "=");
            else
               xfprintf(fp, "%13s ", "");
            /* row/column dual activity */
            if (tagx != LPX_BS)
            {  if (dx == 0.0)
                  xfprintf(fp, "%13s", "< eps");
               else
                  xfprintf(fp, "%13.6g", dx);
            }
            /* end of line */
            xfprintf(fp, "\n");
         }
      }
      xfprintf(fp, "\n");
#if 1
      if (lpx_get_prim_stat(lp) != LPX_P_UNDEF &&
          lpx_get_dual_stat(lp) != LPX_D_UNDEF)
      {  int m = lpx_get_num_rows(lp);
         LPXKKT kkt;
         xfprintf(fp, "Karush-Kuhn-Tucker optimality conditions:\n\n");
         lpx_check_kkt(lp, 1, &kkt);
         xfprintf(fp, "KKT.PE: max.abs.err. = %.2e on row %d\n",
            kkt.pe_ae_max, kkt.pe_ae_row);
         xfprintf(fp, "        max.rel.err. = %.2e on row %d\n",
            kkt.pe_re_max, kkt.pe_re_row);
         switch (kkt.pe_quality)
         {  case 'H':
               xfprintf(fp, "        High quality\n");
               break;
            case 'M':
               xfprintf(fp, "        Medium quality\n");
               break;
            case 'L':
               xfprintf(fp, "        Low quality\n");
               break;
            default:
               xfprintf(fp, "        PRIMAL SOLUTION IS WRONG\n");
               break;
         }
         xfprintf(fp, "\n");
         xfprintf(fp, "KKT.PB: max.abs.err. = %.2e on %s %d\n",
            kkt.pb_ae_max, kkt.pb_ae_ind <= m ? "row" : "column",
            kkt.pb_ae_ind <= m ? kkt.pb_ae_ind : kkt.pb_ae_ind - m);
         xfprintf(fp, "        max.rel.err. = %.2e on %s %d\n",
            kkt.pb_re_max, kkt.pb_re_ind <= m ? "row" : "column",
            kkt.pb_re_ind <= m ? kkt.pb_re_ind : kkt.pb_re_ind - m);
         switch (kkt.pb_quality)
         {  case 'H':
               xfprintf(fp, "        High quality\n");
               break;
            case 'M':
               xfprintf(fp, "        Medium quality\n");
               break;
            case 'L':
               xfprintf(fp, "        Low quality\n");
               break;
            default:
               xfprintf(fp, "        PRIMAL SOLUTION IS INFEASIBLE\n");
               break;
         }
         xfprintf(fp, "\n");
         xfprintf(fp, "KKT.DE: max.abs.err. = %.2e on column %d\n",
            kkt.de_ae_max, kkt.de_ae_col);
         xfprintf(fp, "        max.rel.err. = %.2e on column %d\n",
            kkt.de_re_max, kkt.de_re_col);
         switch (kkt.de_quality)
         {  case 'H':
               xfprintf(fp, "        High quality\n");
               break;
            case 'M':
               xfprintf(fp, "        Medium quality\n");
               break;
            case 'L':
               xfprintf(fp, "        Low quality\n");
               break;
            default:
               xfprintf(fp, "        DUAL SOLUTION IS WRONG\n");
               break;
         }
         xfprintf(fp, "\n");
         xfprintf(fp, "KKT.DB: max.abs.err. = %.2e on %s %d\n",
            kkt.db_ae_max, kkt.db_ae_ind <= m ? "row" : "column",
            kkt.db_ae_ind <= m ? kkt.db_ae_ind : kkt.db_ae_ind - m);
         xfprintf(fp, "        max.rel.err. = %.2e on %s %d\n",
            kkt.db_re_max, kkt.db_re_ind <= m ? "row" : "column",
            kkt.db_re_ind <= m ? kkt.db_re_ind : kkt.db_re_ind - m);
         switch (kkt.db_quality)
         {  case 'H':
               xfprintf(fp, "        High quality\n");
               break;
            case 'M':
               xfprintf(fp, "        Medium quality\n");
               break;
            case 'L':
               xfprintf(fp, "        Low quality\n");
               break;
            default:
               xfprintf(fp, "        DUAL SOLUTION IS INFEASIBLE\n");
               break;
         }
         xfprintf(fp, "\n");
      }
#endif
#if 1
      if (lpx_get_status(lp) == LPX_UNBND)
      {  int m = lpx_get_num_rows(lp);
         int k = lpx_get_ray_info(lp);
         xfprintf(fp, "Unbounded ray: %s %d\n",
            k <= m ? "row" : "column", k <= m ? k : k - m);
         xfprintf(fp, "\n");
      }
#endif
      xfprintf(fp, "End of output\n");
      xfflush(fp);
      if (xferror(fp))
      {  xprintf("lpx_print_sol: can't write to `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      xfclose(fp);
      return 0;
fail: if (fp != NULL) xfclose(fp);
      return 1;
}
int lpx_print_mip(LPX *lp, const char *fname)
{     XFILE *fp;
      int what, round;
#if 0
      if (lpx_get_class(lp) != LPX_MIP)
         fault("lpx_print_mip: error -- not a MIP problem");
#endif
      xprintf(
         "lpx_print_mip: writing MIP problem solution to `%s'...\n",
         fname);
      fp = xfopen(fname, "w");
      if (fp == NULL)
      {  xprintf("lpx_print_mip: can't create `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      /* problem name */
      {  const char *name;
         name = lpx_get_prob_name(lp);
         if (name == NULL) name = "";
         xfprintf(fp, "%-12s%s\n", "Problem:", name);
      }
      /* number of rows (auxiliary variables) */
      {  int nr;
         nr = lpx_get_num_rows(lp);
         xfprintf(fp, "%-12s%d\n", "Rows:", nr);
      }
      /* number of columns (structural variables) */
      {  int nc, nc_int, nc_bin;
         nc = lpx_get_num_cols(lp);
         nc_int = lpx_get_num_int(lp);
         nc_bin = lpx_get_num_bin(lp);
         xfprintf(fp, "%-12s%d (%d integer, %d binary)\n", "Columns:",
            nc, nc_int, nc_bin);
      }
      /* number of non-zeros (constraint coefficients) */
      {  int nz;
         nz = lpx_get_num_nz(lp);
         xfprintf(fp, "%-12s%d\n", "Non-zeros:", nz);
      }
      /* solution status */
      {  int status;
         status = lpx_mip_status(lp);
         xfprintf(fp, "%-12s%s\n", "Status:",
            status == LPX_I_UNDEF  ? "INTEGER UNDEFINED" :
            status == LPX_I_OPT    ? "INTEGER OPTIMAL" :
            status == LPX_I_FEAS   ? "INTEGER NON-OPTIMAL" :
            status == LPX_I_NOFEAS ? "INTEGER EMPTY" : "???");
      }
      /* objective function */
      {  char *name;
         int dir;
         double mip_obj;
         name = (void *)lpx_get_obj_name(lp);
         dir = lpx_get_obj_dir(lp);
         mip_obj = lpx_mip_obj_val(lp);
         xfprintf(fp, "%-12s%s%s%.10g %s\n", "Objective:",
            name == NULL ? "" : name,
            name == NULL ? "" : " = ", mip_obj,
            dir == LPX_MIN ? "(MINimum)" :
            dir == LPX_MAX ? "(MAXimum)" : "(" "???" ")");
      }
      /* main sheet */
      for (what = 1; what <= 2; what++)
      {  int mn, ij;
         xfprintf(fp, "\n");
         xfprintf(fp, "   No. %-12s      Activity     Lower bound   Upp"
            "er bound\n",
            what == 1 ? "  Row name" : "Column name");
         xfprintf(fp, "------ ------------    ------------- -----------"
            "-- -------------\n");
         mn = (what == 1 ? lpx_get_num_rows(lp) : lpx_get_num_cols(lp));
         for (ij = 1; ij <= mn; ij++)
         {  const char *name;
            int kind, typx;
            double lb, ub, vx;
            if (what == 1)
            {  name = lpx_get_row_name(lp, ij);
               if (name == NULL) name = "";
               kind = LPX_CV;
               lpx_get_row_bnds(lp, ij, &typx, &lb, &ub);
               round = lpx_get_int_parm(lp, LPX_K_ROUND);
               lpx_set_int_parm(lp, LPX_K_ROUND, 1);
               vx = lpx_mip_row_val(lp, ij);
               lpx_set_int_parm(lp, LPX_K_ROUND, round);
            }
            else
            {  name = lpx_get_col_name(lp, ij);
               if (name == NULL) name = "";
               kind = lpx_get_col_kind(lp, ij);
               lpx_get_col_bnds(lp, ij, &typx, &lb, &ub);
               round = lpx_get_int_parm(lp, LPX_K_ROUND);
               lpx_set_int_parm(lp, LPX_K_ROUND, 1);
               vx = lpx_mip_col_val(lp, ij);
               lpx_set_int_parm(lp, LPX_K_ROUND, round);
            }
            /* row/column ordinal number */
            xfprintf(fp, "%6d ", ij);
            /* row column/name */
            if (strlen(name) <= 12)
               xfprintf(fp, "%-12s ", name);
            else
               xfprintf(fp, "%s\n%20s", name, "");
            /* row/column kind */
            xfprintf(fp, "%s  ",
               kind == LPX_CV ? " " : kind == LPX_IV ? "*" : "?");
            /* row/column primal activity */
            xfprintf(fp, "%13.6g", vx);
            /* row/column lower and upper bounds */
            switch (typx)
            {  case LPX_FR:
                  break;
               case LPX_LO:
                  xfprintf(fp, " %13.6g", lb);
                  break;
               case LPX_UP:
                  xfprintf(fp, " %13s %13.6g", "", ub);
                  break;
               case LPX_DB:
                  xfprintf(fp, " %13.6g %13.6g", lb, ub);
                  break;
               case LPX_FX:
                  xfprintf(fp, " %13.6g %13s", lb, "=");
                  break;
               default:
                  xassert(typx != typx);
            }
            /* end of line */
            xfprintf(fp, "\n");
         }
      }
      xfprintf(fp, "\n");
#if 1
      if (lpx_mip_status(lp) != LPX_I_UNDEF)
      {  int m = lpx_get_num_rows(lp);
         LPXKKT kkt;
         xfprintf(fp, "Integer feasibility conditions:\n\n");
         lpx_check_int(lp, &kkt);
         xfprintf(fp, "INT.PE: max.abs.err. = %.2e on row %d\n",
            kkt.pe_ae_max, kkt.pe_ae_row);
         xfprintf(fp, "        max.rel.err. = %.2e on row %d\n",
            kkt.pe_re_max, kkt.pe_re_row);
         switch (kkt.pe_quality)
         {  case 'H':
               xfprintf(fp, "        High quality\n");
               break;
            case 'M':
               xfprintf(fp, "        Medium quality\n");
               break;
            case 'L':
               xfprintf(fp, "        Low quality\n");
               break;
            default:
               xfprintf(fp, "        SOLUTION IS WRONG\n");
               break;
         }
         xfprintf(fp, "\n");
         xfprintf(fp, "INT.PB: max.abs.err. = %.2e on %s %d\n",
            kkt.pb_ae_max, kkt.pb_ae_ind <= m ? "row" : "column",
            kkt.pb_ae_ind <= m ? kkt.pb_ae_ind : kkt.pb_ae_ind - m);
         xfprintf(fp, "        max.rel.err. = %.2e on %s %d\n",
            kkt.pb_re_max, kkt.pb_re_ind <= m ? "row" : "column",
            kkt.pb_re_ind <= m ? kkt.pb_re_ind : kkt.pb_re_ind - m);
         switch (kkt.pb_quality)
         {  case 'H':
               xfprintf(fp, "        High quality\n");
               break;
            case 'M':
               xfprintf(fp, "        Medium quality\n");
               break;
            case 'L':
               xfprintf(fp, "        Low quality\n");
               break;
            default:
               xfprintf(fp, "        SOLUTION IS INFEASIBLE\n");
               break;
         }
         xfprintf(fp, "\n");
      }
#endif
      xfprintf(fp, "End of output\n");
      xfflush(fp);
      if (xferror(fp))
      {  xprintf("lpx_print_mip: can't write to `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      xfclose(fp);
      return 0;
fail: if (fp != NULL) xfclose(fp);
      return 1;
}
int lpx_print_ips(LPX *lp, const char *fname)
{     XFILE *fp;
      int what, round;
      xprintf("lpx_print_ips: writing LP problem solution to `%s'...\n",
         fname);
      fp = xfopen(fname, "w");
      if (fp == NULL)
      {  xprintf("lpx_print_ips: can't create `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      /* problem name */
      {  const char *name;
         name = lpx_get_prob_name(lp);
         if (name == NULL) name = "";
         xfprintf(fp, "%-12s%s\n", "Problem:", name);
      }
      /* number of rows (auxiliary variables) */
      {  int nr;
         nr = lpx_get_num_rows(lp);
         xfprintf(fp, "%-12s%d\n", "Rows:", nr);
      }
      /* number of columns (structural variables) */
      {  int nc;
         nc = lpx_get_num_cols(lp);
         xfprintf(fp, "%-12s%d\n", "Columns:", nc);
      }
      /* number of non-zeros (constraint coefficients) */
      {  int nz;
         nz = lpx_get_num_nz(lp);
         xfprintf(fp, "%-12s%d\n", "Non-zeros:", nz);
      }
      /* solution status */
      {  int status;
         status = lpx_ipt_status(lp);
         xfprintf(fp, "%-12s%s\n", "Status:",
            status == LPX_T_UNDEF  ? "INTERIOR UNDEFINED" :
            status == LPX_T_OPT    ? "INTERIOR OPTIMAL" : "???");
      }
      /* objective function */
      {  char *name;
         int dir;
         double obj;
         name = (void *)lpx_get_obj_name(lp);
         dir = lpx_get_obj_dir(lp);
         obj = lpx_ipt_obj_val(lp);
         xfprintf(fp, "%-12s%s%s%.10g %s\n", "Objective:",
            name == NULL ? "" : name,
            name == NULL ? "" : " = ", obj,
            dir == LPX_MIN ? "(MINimum)" :
            dir == LPX_MAX ? "(MAXimum)" : "(" "???" ")");
      }
      /* main sheet */
      for (what = 1; what <= 2; what++)
      {  int mn, ij;
         xfprintf(fp, "\n");
         xfprintf(fp, "   No. %-12s      Activity     Lower bound   Upp"
            "er bound    Marginal\n",
            what == 1 ? "  Row name" : "Column name");
         xfprintf(fp, "------ ------------    ------------- -----------"
            "-- ------------- -------------\n");
         mn = (what == 1 ? lpx_get_num_rows(lp) : lpx_get_num_cols(lp));
         for (ij = 1; ij <= mn; ij++)
         {  const char *name;
            int typx /*, tagx */;
            double lb, ub, vx, dx;
            if (what == 1)
            {  name = lpx_get_row_name(lp, ij);
               if (name == NULL) name = "";
               lpx_get_row_bnds(lp, ij, &typx, &lb, &ub);
               round = lpx_get_int_parm(lp, LPX_K_ROUND);
               lpx_set_int_parm(lp, LPX_K_ROUND, 1);
               vx = lpx_ipt_row_prim(lp, ij);
               dx = lpx_ipt_row_dual(lp, ij);
               lpx_set_int_parm(lp, LPX_K_ROUND, round);
            }
            else
            {  name = lpx_get_col_name(lp, ij);
               if (name == NULL) name = "";
               lpx_get_col_bnds(lp, ij, &typx, &lb, &ub);
               round = lpx_get_int_parm(lp, LPX_K_ROUND);
               lpx_set_int_parm(lp, LPX_K_ROUND, 1);
               vx = lpx_ipt_col_prim(lp, ij);
               dx = lpx_ipt_col_dual(lp, ij);
               lpx_set_int_parm(lp, LPX_K_ROUND, round);
            }
            /* row/column ordinal number */
            xfprintf(fp, "%6d ", ij);
            /* row column/name */
            if (strlen(name) <= 12)
               xfprintf(fp, "%-12s ", name);
            else
               xfprintf(fp, "%s\n%20s", name, "");
            /* two positions are currently not used */
            xfprintf(fp, "   ");
            /* row/column primal activity */
            xfprintf(fp, "%13.6g ", vx);
            /* row/column lower bound */
            if (typx == LPX_LO || typx == LPX_DB || typx == LPX_FX)
               xfprintf(fp, "%13.6g ", lb);
            else
               xfprintf(fp, "%13s ", "");
            /* row/column upper bound */
            if (typx == LPX_UP || typx == LPX_DB)
               xfprintf(fp, "%13.6g ", ub);
            else if (typx == LPX_FX)
               xfprintf(fp, "%13s ", "=");
            else
               xfprintf(fp, "%13s ", "");
            /* row/column dual activity */
            xfprintf(fp, "%13.6g", dx);
            /* end of line */
            xfprintf(fp, "\n");
         }
      }
      xfprintf(fp, "\n");
      xfprintf(fp, "End of output\n");
      xfflush(fp);
      if (xferror(fp))
      {  xprintf("lpx_print_ips: can't write to `%s' - %s\n", fname,
            strerror(errno));
         goto fail;
      }
      xfclose(fp);
      return 0;
fail: if (fp != NULL) xfclose(fp);
      return 1;
}
Beispiel #9
0
int CClp_nnonzeros(CClp *lp)
{     /* RETURNS the number of nonzeros in the LP. */
      return lpx_get_num_nz(lp->lp);
}
Beispiel #10
0
int CClp_limited_dualopt(CClp *lp, int iterationlim, int *status,
      double *objupperlim)
{     /* CALLS the dual simplex method with a limit on the number of
         pivots.
         - upperbound it is used to cutoff the dual simplex method (when
           the objective value reaches upperbound); it can be NULL;
         - status returns the status of the optimization (it can be
           NULL). */
      int stat, ret;
      insist(iterationlim == iterationlim);
      insist(objupperlim == objupperlim);
      if (MSGLEV >= 1)
      {  int m = lpx_get_num_rows(lp->lp);
         int n = lpx_get_num_cols(lp->lp);
         int nz = lpx_get_num_nz(lp->lp);
         print("CClp_limited_dualopt: m = %d; n = %d; nz = %d", m, n,
            nz);
      }
      lpx_set_int_parm(lp->lp, LPX_K_DUAL, 1);
      switch (MSGLEV)
      {  case 0:
            lpx_set_int_parm(lp->lp, LPX_K_MSGLEV, 0);
            lpx_set_int_parm(lp->lp, LPX_K_OUTFRQ, 1000000);
            lpx_set_real_parm(lp->lp, LPX_K_OUTDLY, 1e6);
            break;
         case 1:
            lpx_set_int_parm(lp->lp, LPX_K_MSGLEV, 2);
            lpx_set_int_parm(lp->lp, LPX_K_OUTFRQ, 200);
            lpx_set_real_parm(lp->lp, LPX_K_OUTDLY, 5.0);
            break;
         case 2:
            lpx_set_int_parm(lp->lp, LPX_K_MSGLEV, 3);
            lpx_set_int_parm(lp->lp, LPX_K_OUTFRQ, 200);
            lpx_set_real_parm(lp->lp, LPX_K_OUTDLY, 0.0);
            break;
         default:
            insist(MSGLEV != MSGLEV);
      }
      ret = lpx_simplex(lp->lp);
      if (ret == LPX_E_FAULT)
      {  if (MSGLEV >= 1) print("CClp_limited_dualopt: restarting from "
            "advanced basis...");
         lpx_adv_basis(lp->lp);
         ret = lpx_simplex(lp->lp);
      }
      if (ret != LPX_E_OK)
      {  print("CClp_limited_dualopt: lpx_simplex failed; return code ="
            " %d", ret);
         if (status) *status = CClp_FAILURE;
         ret = 1;
         goto done;
      }
      stat = lpx_get_status(lp->lp);
      if (stat == LPX_OPT)
      {  if (status) *status = CClp_SUCCESS;
         ret = 0;
      }
      else if (stat == LPX_NOFEAS)
      {  if (status) *status = CClp_INFEASIBLE;
         ret = 0;
      }
      else
      {  print("CClp_limited_dualopt: optimization status = %d", stat);
         if (status) *status = CClp_FAILURE;
         ret = 1;
      }
done: return ret;
}
Beispiel #11
0
int lpx_interior(LPX *_lp)
{   /* easy-to-use driver to the interior-point method */
    struct dsa _dsa, *dsa = &_dsa;
    int ret, status;
    double *row_pval, *row_dval, *col_pval, *col_dval;
    /* initialize working area */
    dsa->lp = _lp;
    dsa->orig_m = lpx_get_num_rows(dsa->lp);
    dsa->orig_n = lpx_get_num_cols(dsa->lp);
    dsa->ref = NULL;
    dsa->m = 0;
    dsa->n = 0;
    dsa->size = 0;
    dsa->ne = 0;
    dsa->ia = NULL;
    dsa->ja = NULL;
    dsa->ar = NULL;
    dsa->b = NULL;
    dsa->c = NULL;
    dsa->x = NULL;
    dsa->y = NULL;
    dsa->z = NULL;
    /* check if the problem is empty */
    if (!(dsa->orig_m > 0 && dsa->orig_n > 0))
    {   print("lpx_interior: problem has no rows and/or columns");
        ret = LPX_E_FAULT;
        goto done;
    }
    /* issue warning about dense columns */
    if (dsa->orig_m >= 200)
    {   int j, len, ndc = 0;
        for (j = 1; j <= dsa->orig_n; j++)
        {   len = lpx_get_mat_col(dsa->lp, j, NULL, NULL);
            if ((double)len > 0.30 * (double)dsa->orig_m) ndc++;
        }
        if (ndc == 1)
            print("lpx_interior: WARNING: PROBLEM HAS ONE DENSE COLUMN")
            ;
        else if (ndc > 0)
            print("lpx_interior: WARNING: PROBLEM HAS %d DENSE COLUMNS",
                  ndc);
    }
    /* determine dimension of transformed LP */
    print("lpx_interior: original LP problem has %d rows and %d colum"
          "ns", dsa->orig_m, dsa->orig_n);
    calc_mn(dsa);
    print("lpx_interior: transformed LP problem has %d rows and %d co"
          "lumns", dsa->m, dsa->n);
    /* transform original LP to standard formulation */
    dsa->ref = ucalloc(1+dsa->orig_m+dsa->orig_n, sizeof(int));
    dsa->size = lpx_get_num_nz(dsa->lp);
    if (dsa->size < dsa->m) dsa->size = dsa->m;
    if (dsa->size < dsa->n) dsa->size = dsa->n;
    dsa->ne = 0;
    dsa->ia = ucalloc(1+dsa->size, sizeof(int));
    dsa->ja = ucalloc(1+dsa->size, sizeof(int));
    dsa->ar = ucalloc(1+dsa->size, sizeof(double));
    dsa->b = ucalloc(1+dsa->m, sizeof(double));
    dsa->c = ucalloc(1+dsa->n, sizeof(double));
    transform(dsa);
    /* solve the transformed LP problem */
    {   int *A_ptr = ucalloc(1+dsa->m+1, sizeof(int));
        int *A_ind = ucalloc(1+dsa->ne, sizeof(int));
        double *A_val = ucalloc(1+dsa->ne, sizeof(double));
        int i, k, pos, len;
        /* determine row lengths */
        for (i = 1; i <= dsa->m; i++)
            A_ptr[i] = 0;
        for (k = 1; k <= dsa->ne; k++)
            A_ptr[dsa->ia[k]]++;
        /* set up row pointers */
        pos = 1;
        for (i = 1; i <= dsa->m; i++)
            len = A_ptr[i], pos += len, A_ptr[i] = pos;
        A_ptr[dsa->m+1] = pos;
        insist(pos - 1 == dsa->ne);
        /* build the matrix */
        for (k = 1; k <= dsa->ne; k++)
        {   pos = --A_ptr[dsa->ia[k]];
            A_ind[pos] = dsa->ja[k];
            A_val[pos] = dsa->ar[k];
        }
        ufree(dsa->ia), dsa->ia = NULL;
        ufree(dsa->ja), dsa->ja = NULL;
        ufree(dsa->ar), dsa->ar = NULL;
        dsa->x = ucalloc(1+dsa->n, sizeof(double));
        dsa->y = ucalloc(1+dsa->m, sizeof(double));
        dsa->z = ucalloc(1+dsa->n, sizeof(double));
        ret = ipm_main(dsa->m, dsa->n, A_ptr, A_ind, A_val, dsa->b,
                       dsa->c, dsa->x, dsa->y, dsa->z);
        ufree(A_ptr);
        ufree(A_ind);
        ufree(A_val);
        ufree(dsa->b), dsa->b = NULL;
        ufree(dsa->c), dsa->c = NULL;
    }
    /* analyze return code reported by the solver */
    switch (ret)
    {
    case 0:
        /* optimal solution found */
        ret = LPX_E_OK;
        break;
    case 1:
        /* problem has no feasible (primal or dual) solution */
        ret = LPX_E_NOFEAS;
        break;
    case 2:
        /* no convergence */
        ret = LPX_E_NOCONV;
        break;
    case 3:
        /* iterations limit exceeded */
        ret = LPX_E_ITLIM;
        break;
    case 4:
        /* numerical instability on solving Newtonian system */
        ret = LPX_E_INSTAB;
        break;
    default:
        insist(ret != ret);
    }
    /* recover solution of original LP */
    row_pval = ucalloc(1+dsa->orig_m, sizeof(double));
    row_dval = ucalloc(1+dsa->orig_m, sizeof(double));
    col_pval = ucalloc(1+dsa->orig_n, sizeof(double));
    col_dval = ucalloc(1+dsa->orig_n, sizeof(double));
    restore(dsa, row_pval, row_dval, col_pval, col_dval);
    ufree(dsa->ref), dsa->ref = NULL;
    ufree(dsa->x), dsa->x = NULL;
    ufree(dsa->y), dsa->y = NULL;
    ufree(dsa->z), dsa->z = NULL;
    /* store solution components into the problem object */
    status = (ret == LPX_E_OK ? LPX_T_OPT : LPX_T_UNDEF);
    lpx_put_ipt_soln(dsa->lp, status, row_pval, row_dval, col_pval,
                     col_dval);
    ufree(row_pval);
    ufree(row_dval);
    ufree(col_pval);
    ufree(col_dval);
done: /* return to the calling program */
    return ret;
}
Beispiel #12
0
void ipp_load_orig(IPP *ipp, LPX *orig)
{     IPPROW **row;
      IPPCOL *col;
      int i, j, k, type, len, *ind;
      double lb, ub, *val;
      /* save some information about the original problem */
      ipp->orig_m = lpx_get_num_rows(orig);
      ipp->orig_n = lpx_get_num_cols(orig);
      ipp->orig_nnz = lpx_get_num_nz(orig);
      ipp->orig_dir = lpx_get_obj_dir(orig);
      /* allocate working arrays */
      row = xcalloc(1+ipp->orig_m, sizeof(IPPROW *));
      ind = xcalloc(1+ipp->orig_m, sizeof(int));
      val = xcalloc(1+ipp->orig_m, sizeof(double));
      /* copy rows of the original problem into the workspace */
      for (i = 1; i <= ipp->orig_m; i++)
      {  type = lpx_get_row_type(orig, i);
         if (type == LPX_FR || type == LPX_UP)
            lb = -DBL_MAX;
         else
            lb = lpx_get_row_lb(orig, i);
         if (type == LPX_FR || type == LPX_LO)
            ub = +DBL_MAX;
         else
            ub = lpx_get_row_ub(orig, i);
         row[i] = ipp_add_row(ipp, lb, ub);
      }
      /* copy columns of the original problem into the workspace; each
         column created in the workspace is assigned a reference number
         which is its ordinal number in the original problem */
      for (j = 1; j <= ipp->orig_n; j++)
      {  type = lpx_get_col_type(orig, j);
         if (type == LPX_FR || type == LPX_UP)
            lb = -DBL_MAX;
         else
            lb = lpx_get_col_lb(orig, j);
         if (type == LPX_FR || type == LPX_LO)
            ub = +DBL_MAX;
         else
            ub = lpx_get_col_ub(orig, j);
         col = ipp_add_col(ipp, lpx_get_col_kind(orig, j) == LPX_IV,
            lb, ub, lpx_get_obj_coef(orig, j));
         len = lpx_get_mat_col(orig, j, ind, val);
         for (k = 1; k <= len; k++)
            ipp_add_aij(ipp, row[ind[k]], col, val[k]);
      }
      /* copy the constant term of the original objective function */
      ipp->c0 = lpx_get_obj_coef(orig, 0);
      /* if the original problem is maximization, change the sign of
         the objective function, because the transformed problem to be
         processed by the presolver must be minimization */
      if (ipp->orig_dir == LPX_MAX)
      {  for (col = ipp->col_ptr; col != NULL; col = col->next)
            col->c = - col->c;
         ipp->c0 = - ipp->c0;
      }
      /* free working arrays */
      xfree(row);
      xfree(ind);
      xfree(val);
      return;
}
Beispiel #13
0
int lpx_intopt(LPX *_mip)
{     IPP *ipp = NULL;
      LPX *orig = _mip, *prob = NULL;
      int orig_m, orig_n, i, j, ret, i_stat;
      /* the problem must be of MIP class */
      if (lpx_get_class(orig) != LPX_MIP)
      {  print("lpx_intopt: problem is not of MIP class");
         ret = LPX_E_FAULT;
         goto done;
      }
      /* the problem must have at least one row and one column */
      orig_m = lpx_get_num_rows(orig);
      orig_n = lpx_get_num_cols(orig);
      if (!(orig_m > 0 && orig_n > 0))
      {  print("lpx_intopt: problem has no rows/columns");
         ret = LPX_E_FAULT;
         goto done;
      }
      /* check that each double-bounded row and column has bounds */
      for (i = 1; i <= orig_m; i++)
      {  if (lpx_get_row_type(orig, i) == LPX_DB)
         {  if (lpx_get_row_lb(orig, i) >= lpx_get_row_ub(orig, i))
            {  print("lpx_intopt: row %d has incorrect bounds", i);
               ret = LPX_E_FAULT;
               goto done;
            }
         }
      }
      for (j = 1; j <= orig_n; j++)
      {  if (lpx_get_col_type(orig, j) == LPX_DB)
         {  if (lpx_get_col_lb(orig, j) >= lpx_get_col_ub(orig, j))
            {  print("lpx_intopt: column %d has incorrect bounds", j);
               ret = LPX_E_FAULT;
               goto done;
            }
         }
      }
      /* bounds of all integer variables must be integral */
      for (j = 1; j <= orig_n; j++)
      {  int type;
         double lb, ub;
         if (lpx_get_col_kind(orig, j) != LPX_IV) continue;
         type = lpx_get_col_type(orig, j);
         if (type == LPX_LO || type == LPX_DB || type == LPX_FX)
         {  lb = lpx_get_col_lb(orig, j);
            if (lb != floor(lb))
            {  print("lpx_intopt: integer column %d has non-integer low"
                  "er bound or fixed value %g", j, lb);
               ret = LPX_E_FAULT;
               goto done;
            }
         }
         if (type == LPX_UP || type == LPX_DB)
         {  ub = lpx_get_col_ub(orig, j);
            if (ub != floor(ub))
            {  print("lpx_intopt: integer column %d has non-integer upp"
                  "er bound %g", j, ub);
               ret = LPX_E_FAULT;
               goto done;
            }
         }
      }
      /* reset the status of MIP solution */
      lpx_put_mip_soln(orig, LPX_I_UNDEF, NULL, NULL);
      /* create MIP presolver workspace */
      ipp = ipp_create_wksp();
      /* load the original problem into the presolver workspace */
      ipp_load_orig(ipp, orig);
      /* perform basic MIP presolve analysis */
      switch (ipp_basic_tech(ipp))
      {  case 0:
            /* no infeasibility is detected */
            break;
         case 1:
nopfs:      /* primal infeasibility is detected */
            print("PROBLEM HAS NO PRIMAL FEASIBLE SOLUTION");
            ret = LPX_E_NOPFS;
            goto done;
         case 2:
            /* dual infeasibility is detected */
nodfs:      print("LP RELAXATION HAS NO DUAL FEASIBLE SOLUTION");
            ret = LPX_E_NODFS;
            goto done;
         default:
            insist(ipp != ipp);
      }
      /* reduce column bounds */
      switch (ipp_reduce_bnds(ipp))
      {  case 0:  break;
         case 1:  goto nopfs;
         default: insist(ipp != ipp);
      }
      /* perform basic MIP presolve analysis */
      switch (ipp_basic_tech(ipp))
      {  case 0:  break;
         case 1:  goto nopfs;
         case 2:  goto nodfs;
         default: insist(ipp != ipp);
      }
      /* replace general integer variables by sum of binary variables,
         if required */
      if (lpx_get_int_parm(orig, LPX_K_BINARIZE))
         ipp_binarize(ipp);
      /* perform coefficient reduction */
      ipp_reduction(ipp);
      /* if the resultant problem is empty, it has an empty solution,
         which is optimal */
      if (ipp->row_ptr == NULL || ipp->col_ptr == NULL)
      {  insist(ipp->row_ptr == NULL);
         insist(ipp->col_ptr == NULL);
         print("Objective value = %.10g",
            ipp->orig_dir == LPX_MIN ? +ipp->c0 : -ipp->c0);
         print("INTEGER OPTIMAL SOLUTION FOUND BY MIP PRESOLVER");
         /* allocate recovered solution segment */
         ipp->col_stat = ucalloc(1+ipp->ncols, sizeof(int));
         ipp->col_mipx = ucalloc(1+ipp->ncols, sizeof(double));
         for (j = 1; j <= ipp->ncols; j++) ipp->col_stat[j] = 0;
         /* perform MIP postsolve processing */
         ipp_postsolve(ipp);
         /* unload recovered MIP solution and store it in the original
            problem object */
         ipp_unload_sol(ipp, orig, LPX_I_OPT);
         ret = LPX_E_OK;
         goto done;
      }
      /* build resultant MIP problem object */
      prob = ipp_build_prob(ipp);
      /* display some statistics */
      {  int m = lpx_get_num_rows(prob);
         int n = lpx_get_num_cols(prob);
         int nnz = lpx_get_num_nz(prob);
         int ni = lpx_get_num_int(prob);
         int nb = lpx_get_num_bin(prob);
         char s[50];
         print("lpx_intopt: presolved MIP has %d row%s, %d column%s, %d"
            " non-zero%s", m, m == 1 ? "" : "s", n, n == 1 ? "" : "s",
            nnz, nnz == 1 ? "" : "s");
         if (nb == 0)
            strcpy(s, "none of");
         else if (ni == 1 && nb == 1)
            strcpy(s, "");
         else if (nb == 1)
            strcpy(s, "one of");
         else if (nb == ni)
            strcpy(s, "all of");
         else
            sprintf(s, "%d of", nb);
         print("lpx_intopt: %d integer column%s, %s which %s binary",
            ni, ni == 1 ? "" : "s", s, nb == 1 ? "is" : "are");
      }
      /* inherit some control parameters and statistics */
      lpx_set_int_parm(prob, LPX_K_PRICE, lpx_get_int_parm(orig,
         LPX_K_PRICE));
      lpx_set_real_parm(prob, LPX_K_RELAX, lpx_get_real_parm(orig,
         LPX_K_RELAX));
      lpx_set_real_parm(prob, LPX_K_TOLBND, lpx_get_real_parm(orig,
         LPX_K_TOLBND));
      lpx_set_real_parm(prob, LPX_K_TOLDJ, lpx_get_real_parm(orig,
         LPX_K_TOLDJ));
      lpx_set_real_parm(prob, LPX_K_TOLPIV, lpx_get_real_parm(orig,
         LPX_K_TOLPIV));
      lpx_set_int_parm(prob, LPX_K_ITLIM, lpx_get_int_parm(orig,
         LPX_K_ITLIM));
      lpx_set_int_parm(prob, LPX_K_ITCNT, lpx_get_int_parm(orig,
         LPX_K_ITCNT));
      lpx_set_real_parm(prob, LPX_K_TMLIM, lpx_get_real_parm(orig,
         LPX_K_TMLIM));
      lpx_set_int_parm(prob, LPX_K_BRANCH, lpx_get_int_parm(orig,
         LPX_K_BRANCH));
      lpx_set_int_parm(prob, LPX_K_BTRACK, lpx_get_int_parm(orig,
         LPX_K_BTRACK));
      lpx_set_real_parm(prob, LPX_K_TOLINT, lpx_get_real_parm(orig,
         LPX_K_TOLINT));
      lpx_set_real_parm(prob, LPX_K_TOLOBJ, lpx_get_real_parm(orig,
         LPX_K_TOLOBJ));
      /* build an advanced initial basis */
      lpx_adv_basis(prob);
      /* solve LP relaxation */
      print("Solving LP relaxation...");
      switch (lpx_simplex(prob))
      {  case LPX_E_OK:
            break;
         case LPX_E_ITLIM:
            ret = LPX_E_ITLIM;
            goto done;
         case LPX_E_TMLIM:
            ret = LPX_E_TMLIM;
            goto done;
         default:
            print("lpx_intopt: cannot solve LP relaxation");
            ret = LPX_E_SING;
            goto done;
      }
      /* analyze status of the basic solution */
      switch (lpx_get_status(prob))
      {  case LPX_OPT:
            break;
         case LPX_NOFEAS:
            ret = LPX_E_NOPFS;
            goto done;
         case LPX_UNBND:
            ret = LPX_E_NODFS;
            goto done;
         default:
            insist(prob != prob);
      }
      /* generate cutting planes, if necessary */
      if (lpx_get_int_parm(orig, LPX_K_USECUTS))
      {  ret =  generate_cuts(prob);
         if (ret != LPX_E_OK) goto done;
      }
      /* call the branch-and-bound solver */
      ret = lpx_integer(prob);
      /* determine status of MIP solution */
      i_stat = lpx_mip_status(prob);
      if (i_stat == LPX_I_OPT || i_stat == LPX_I_FEAS)
      {  /* load MIP solution of the resultant problem into presolver
            workspace */
         ipp_load_sol(ipp, prob);
         /* perform MIP postsolve processing */
         ipp_postsolve(ipp);
         /* unload recovered MIP solution and store it in the original
            problem object */
         ipp_unload_sol(ipp, orig, i_stat);
      }
      else
      {  /* just set the status of MIP solution */
         lpx_put_mip_soln(orig, i_stat, NULL, NULL);
      }
done: /* copy back statistics about spent resources */
      if (prob != NULL)
      {  lpx_set_int_parm(orig, LPX_K_ITLIM, lpx_get_int_parm(prob,
            LPX_K_ITLIM));
         lpx_set_int_parm(orig, LPX_K_ITCNT, lpx_get_int_parm(prob,
            LPX_K_ITCNT));
         lpx_set_real_parm(orig, LPX_K_TMLIM, lpx_get_real_parm(prob,
            LPX_K_TMLIM));
      }
      /* delete the resultant problem object */
      if (prob != NULL) lpx_delete_prob(prob);
      /* delete MIP presolver workspace */
      if (ipp != NULL) ipp_delete_wksp(ipp);
      return ret;
}
Beispiel #14
0
static int generate_cuts(LPX *prob)
{     int prob_m, prob_n, prob_nz, msg_lev, dual, nrows, it_cnt, ret;
      double out_dly, tm_lim, tm_lag = 0.0, tm_beg = utime();
      print("Generating cutting planes...");
      /* determine the number of rows, columns, and non-zeros on entry
         to the routine */
      prob_m = lpx_get_num_rows(prob);
      prob_n = lpx_get_num_cols(prob);
      prob_nz = lpx_get_num_nz(prob);
      /* save some control parameters */
      msg_lev = lpx_get_int_parm(prob, LPX_K_MSGLEV);
      dual = lpx_get_int_parm(prob, LPX_K_DUAL);
      out_dly = lpx_get_real_parm(prob, LPX_K_OUTDLY);
      tm_lim = lpx_get_real_parm(prob, LPX_K_TMLIM);
      /* and set their new values needed for re-optimization */
      lpx_set_int_parm(prob, LPX_K_MSGLEV, 1);
      lpx_set_int_parm(prob, LPX_K_DUAL, 1);
      lpx_set_real_parm(prob, LPX_K_OUTDLY, 10.0);
      lpx_set_real_parm(prob, LPX_K_TMLIM, -1.0);
loop: /* main loop starts here */
      /* display current status of the problem */
      if (utime() - tm_lag >= 5.0 - 0.001)
         show_status(prob, prob_m, prob_nz), tm_lag = utime();
      /* check if the patience has been exhausted */
      if (tm_lim >= 0.0 && tm_lim <= utime() - tm_beg)
      {  ret = LPX_E_TMLIM;
         goto done;
      }
      /* not more than 500 cut inequalities are allowed */
      if (lpx_get_num_rows(prob) - prob_m >= 500)
      {  ret = LPX_E_OK;
         goto done;
      }
      /* not more than 50,000 cut coefficients are allowed */
      if (lpx_get_num_nz(prob) - prob_nz >= 50000)
      {  ret = LPX_E_OK;
         goto done;
      }
      /* try to generate Gomory's mixed integer cut */
      nrows = lpx_get_num_rows(prob);
      gen_gomory_cut(prob, prob_n);
      if (nrows == lpx_get_num_rows(prob))
      {  /* nothing has been generated */
         ret = LPX_E_OK;
         goto done;
      }
      /* re-optimize current LP relaxation using dual simplex */
      it_cnt = lpx_get_int_parm(prob, LPX_K_ITCNT);
      switch (lpx_simplex(prob))
      {  case LPX_E_OK:
            break;
         case LPX_E_ITLIM:
            ret = LPX_E_ITLIM;
            goto done;
         default:
            ret = LPX_E_SING;
            goto done;
      }
      if (it_cnt == lpx_get_int_parm(prob, LPX_K_ITCNT))
      {  ret = LPX_E_OK;
         goto done;
      }
      /* analyze status of the basic solution */
      switch (lpx_get_status(prob))
      {  case LPX_OPT:
            break;
         case LPX_NOFEAS:
            ret = LPX_E_NOPFS;
            goto done;
         default:
            insist(prob != prob);
      }
      /* continue generating cutting planes */
      goto loop;
done: /* display final status of the problem */
      show_status(prob, prob_m, prob_nz);
      switch (ret)
      {  case LPX_E_OK:
            break;
         case LPX_E_NOPFS:
            print("PROBLEM HAS NO INTEGER FEASIBLE SOLUTION");
            break;
         case LPX_E_ITLIM:
            print("ITERATIONS LIMIT EXCEEDED; SEARCH TERMINATED");
            break;
         case LPX_E_TMLIM:
            print("TIME LIMIT EXCEEDED; SEARCH TERMINATED");
            break;
         case LPX_E_SING:
            print("lpx_intopt: cannot re-optimize LP relaxation");
            break;
         default:
            insist(ret != ret);
      }
      /* decrease the time limit by spent amount of the time */
      if (tm_lim >= 0.0)
      {  tm_lim -= (utime() - tm_beg);
         if (tm_lim < 0.0) tm_lim = 0.0;
      }
      /* restore some control parameters and update statistics */
      lpx_set_int_parm(prob, LPX_K_MSGLEV, msg_lev);
      lpx_set_int_parm(prob, LPX_K_DUAL, dual);
      lpx_set_real_parm(prob, LPX_K_OUTDLY, out_dly);
      lpx_set_real_parm(prob, LPX_K_TMLIM, tm_lim);
      return ret;
}
Beispiel #15
0
int lpx_print_sens_bnds(LPX *lp, char *fname)
{     FILE *fp = NULL;
      int what, round;
      print("lpx_print_sens_bnds: writing LP problem solution bounds to"
         " `%s'...", fname);
#if 1
      /* added by mao */
      /* this routine needs factorization of the current basis matrix
         which, however, does not exist if the basic solution was
         obtained by the lp presolver; therefore we should warm up the
         basis to be sure that the factorization is valid (note that if
         the factorization exists, lpx_warm_up does nothing) */
      lpx_warm_up(lp);
#endif
#if 0 /* 21/XII-2003 by mao */
      if (lp->b_stat == LPX_B_UNDEF)
#else
      if (!lpx_is_b_avail(lp))
#endif
      {  print("lpx_print_sens_bnds: basis information not available (m"
            "ay be a presolve issue)");
         goto fail;
      }
      fp = ufopen(fname, "w");
      if (fp == NULL)
      {  print("lpx_print_sens_bnds: can't create `%s' - %s", fname,
            strerror(errno));
         goto fail;
      }
      /* problem name */
      {  char *name;
         name = lpx_get_prob_name(lp);
         if (name == NULL) name = "";
         fprintf(fp, "%-12s%s\n", "Problem:", name);
      }
      /* number of rows (auxiliary variables) */
      {  int nr;
         nr = lpx_get_num_rows(lp);
         fprintf(fp, "%-12s%d\n", "Rows:", nr);
      }
      /* number of columns (structural variables) */
      {  int nc;
         nc = lpx_get_num_cols(lp);
         fprintf(fp, "%-12s%d\n", "Columns:", nc);
      }
      /* number of non-zeros (constraint coefficients) */
      {  int nz;
         nz = lpx_get_num_nz(lp);
         fprintf(fp, "%-12s%d\n", "Non-zeros:", nz);
      }
      /* solution status */
      {  int status;
         status = lpx_get_status(lp);
         fprintf(fp, "%-12s%s\n", "Status:",
            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" : "???");
      }
      /* explanation/warning */
      {  fprintf(fp, "\nExplanation:  This file presents amounts by whi"
            "ch objective coefficients,\n");
         fprintf(fp, "constraint bounds, and variable bounds may be cha"
            "nged in the original problem\n");
         fprintf(fp, "while the optimal basis remains the same.  Note t"
            "hat the optimal solution\n");
         fprintf(fp, "and objective value may change even though the ba"
            "sis remains the same.\n");
         fprintf(fp, "These bounds assume that all parameters remain fi"
            "xed except the one in\n");
         fprintf(fp, "question.  If more than one parameter is changed,"
            " it is possible for the\n");
         fprintf(fp, "optimal basis to change even though each paramete"
            "r stays within its bounds.\n");
         fprintf(fp, "For more details, consult a text on linear progra"
            "mming.\n");
      }
      /* Sensitivity ranges if solution was optimal */
      {  int status;
         status = lpx_get_status(lp);
         if (status == LPX_OPT)
         {  int i,j,k,m,n;
            int dir;
            double max_inc, max_dec;
            int *index;
            double *val;
            fprintf(fp, "\nObjective Coefficient Analysis\n");
            fprintf(fp, "   No.  Column name St    Value       Max incr"
               "ease  Max decrease\n");
            fprintf(fp, "------ ------------ -- ------------- ---------"
               "---- ------------- \n");
            n = lpx_get_num_cols(lp);
            m = lpx_get_num_rows(lp);
            dir = lpx_get_obj_dir(lp);
            /* allocate memory for index and val arrays */
            index = ucalloc(1+n+m, sizeof(int));
            val   = ucalloc(1+n+m, sizeof(double));
            for (j = 1; j <= n; j++)
            {  char *name;
               int typx, tagx;
               double lb, ub, vx, dx;
               name = lpx_get_col_name(lp, j);
               if (name == NULL) name = "";
               lpx_get_col_bnds(lp, j, &typx, &lb, &ub);
#if 0 /* 21/XII-2003 by mao */
               round = lp->round, lp->round = 1;
               lpx_get_col_info(lp, j, &tagx, &vx, &dx);
               lp->round = round;
#else
               round = lpx_get_int_parm(lp, LPX_K_ROUND);
               lpx_set_int_parm(lp, LPX_K_ROUND, 1);
               lpx_get_col_info(lp, j, &tagx, &vx, &dx);
               lpx_set_int_parm(lp, LPX_K_ROUND, round);
#endif
               /* row/column ordinal number */
               fprintf(fp, "%6d ", j);
               /* row column/name */
               if (strlen(name) <= 12)
                  fprintf(fp, "%-12s ", name);
               else
                  fprintf(fp, "%s\n%20s", name, "");
               /* row/column status */
               fprintf(fp, "%s ",
                  tagx == LPX_BS ? "B " :
                  tagx == LPX_NL ? "NL" :
                  tagx == LPX_NU ? "NU" :
                  tagx == LPX_NF ? "NF" :
                  tagx == LPX_NS ? "NS" : "??");
               /* objective coefficient */
               fprintf(fp, "%13.6g ", lpx_get_obj_coef(lp, j));
               if (tagx == LPX_NL)
               {  if (dir==LPX_MIN)
                  {  /* reduced cost must be positive */
                     max_inc = DBL_MAX; /* really represents infinity */
                     max_dec = dx;
                  }
                  else
                  {  /* reduced cost must be negative */
                     max_inc = -dx;
                     max_dec = DBL_MAX; /* means infinity */
                  }
               }
               if (tagx == LPX_NU)
               {  if (dir==LPX_MIN)
                  {  /* reduced cost must be negative */
                     max_inc = -dx;
                     max_dec = DBL_MAX;
                  }
                  else
                  {  max_inc = DBL_MAX;
                     max_dec = dx;
                  }
               }
               if (tagx == LPX_NF)
               {  /* can't change nonbasic free variables' cost */
                  max_inc = 0.0;
                  max_dec = 0.0;
               }
               if (tagx == LPX_NS)
               {  /* doesn't matter what happens to the cost */
                  max_inc = DBL_MAX;
                  max_dec = DBL_MAX;
               }
               if (tagx == LPX_BS)
               {  int len;
                  /* We need to see how this objective coefficient
                     affects reduced costs of other variables */
                  len = lpx_eval_tab_row(lp, m+j, index, val);
                  max_inc = DBL_MAX;
                  max_dec = DBL_MAX;
                  for (i = 1; i <= len; i++)
                  {  /*int stat;*/
                     int tagx2;
                     double vx2, dx2;
                     double delta;
                     if (index[i]>m)
                        lpx_get_col_info(lp, index[i]-m, &tagx2, &vx2,
                           &dx2);
                     else
                        lpx_get_row_info(lp, index[i], &tagx2, &vx2,
                           &dx2);
                     if (tagx2 == LPX_NL)
                     {  if (val[i] != 0.0)
                        {  delta = dx2 / val[i];
                           if (delta < 0 && -delta < max_inc)
                              max_inc = -delta;
                           else if (delta >0 && delta < max_dec)
                              max_dec = delta;
                        }
                     }
                     if (tagx2 == LPX_NU)
                     {  if (val[i] != 0.0)
                        {  delta = dx2 / val[i];
                           if (delta < 0 && -delta < max_inc)
                              max_inc = -delta;
                           else if (delta > 0 && delta < max_dec)
                              max_dec = delta;
                        }
                     }
                     if (tagx2 == LPX_NF)
                     {  if (val[i] != 0.0)
                        {  max_inc = 0.0;
                           max_dec = 0.0;
                        }
                     }
                  }
               }
               if (max_inc == -0.0) max_inc = 0.0;
               if (max_dec == -0.0) max_dec = 0.0;
               if (max_inc == DBL_MAX)
                  fprintf(fp, "%13s ", "infinity");
               else if (max_inc < 1.0e-12 && max_inc > 0)
                  fprintf(fp, "%13s ", "< eps");
               else
                  fprintf(fp, "%13.6g ", max_inc);
               if (max_dec == DBL_MAX)
                  fprintf(fp, "%13s ", "infinity");
               else if (max_dec < 1.0e-12 && max_dec > 0)
                  fprintf(fp, "%13s ", "< eps");
               else
                  fprintf(fp, "%13.6g ", max_dec);
               fprintf(fp, "\n");
            }
            for (what = 1; what <= 2; what++)
            {  int ij, mn;
               fprintf(fp, "\n");
               fprintf(fp, "%s Analysis\n",
                  what==1? "Constraint Bounds":"Variable Bounds");
               fprintf(fp, "   No. %12s St    Value       Max increase "
                  " Max decrease\n",
                  what==1 ? " Row name":"Column name");
               fprintf(fp, "------ ------------ -- ------------- ------"
                  "------- ------------- \n");
               mn = what==1 ? m : n;
               for (ij = 1; ij <= mn; ij++)
               {  char *name;
                  int typx, tagx;
                  double lb, ub, vx, dx;
                  if (what==1)
                     name = lpx_get_row_name(lp, ij);
                  else
                     name = lpx_get_col_name(lp, ij);
                  if (name == NULL) name = "";
#if 0 /* 21/XII-2003 by mao */
                  if (what==1)
                  {  lpx_get_row_bnds(lp, ij, &typx, &lb, &ub);
                     round = lp->round, lp->round = 1;
                     lpx_get_row_info(lp, ij, &tagx, &vx, &dx);
                     lp->round = round;
                  }
                  else
                  {  lpx_get_col_bnds(lp, ij, &typx, &lb, &ub);
                     round = lp->round, lp->round = 1;
                     lpx_get_col_info(lp, ij, &tagx, &vx, &dx);
                     lp->round = round;
                  }
#else
                  round = lpx_get_int_parm(lp, LPX_K_ROUND);
                  lpx_set_int_parm(lp, LPX_K_ROUND, 1);
                  if (what==1)
                  {  lpx_get_row_bnds(lp, ij, &typx, &lb, &ub);
                     lpx_get_row_info(lp, ij, &tagx, &vx, &dx);
                  }
                  else
                  {  lpx_get_col_bnds(lp, ij, &typx, &lb, &ub);
                     lpx_get_col_info(lp, ij, &tagx, &vx, &dx);
                  }
                  lpx_set_int_parm(lp, LPX_K_ROUND, round);
#endif
                  /* row/column ordinal number */
                  fprintf(fp, "%6d ", ij);
                  /* row column/name */
                  if (strlen(name) <= 12)
                     fprintf(fp, "%-12s ", name);
                  else
                     fprintf(fp, "%s\n%20s", name, "");
                  /* row/column status */
                  fprintf(fp, "%s ",
                     tagx == LPX_BS ? "B " :
                     tagx == LPX_NL ? "NL" :
                     tagx == LPX_NU ? "NU" :
                     tagx == LPX_NF ? "NF" :
                     tagx == LPX_NS ? "NS" : "??");
                  fprintf(fp, "\n");
                  /* first check lower bound */
                  if (typx == LPX_LO || typx == LPX_DB ||
                      typx == LPX_FX)
                  {  int at_lower;
                     at_lower = 0;
                     if (tagx == LPX_BS || tagx == LPX_NU)
                     {  max_inc = vx - lb;
                        max_dec = DBL_MAX;
                     }
                     if (tagx == LPX_NS)
                     {  max_inc = 0.0;
                        max_dec = 0.0;
                        if (dir == LPX_MIN && dx > 0) at_lower = 1;
                        if (dir == LPX_MAX && dx < 0) at_lower = 1;
                     }
                     if (tagx == LPX_NL || at_lower == 1)
                     {  int len;
                        /* we have to see how it affects basic
                           variables */
                        len = lpx_eval_tab_col(lp, what==1?ij:ij+m,
                           index, val);
                        k = lpx_prim_ratio_test(lp, len, index, val, 1,
                           10e-7);
                        max_inc = DBL_MAX;
                        if (k != 0)
                        {  /*int stat;*/
                           int tagx2, typx2;
                           double vx2, dx2, lb2, ub2;
                           /*double delta;*/
                           double alpha;
                           int l;
                           for (l = 1; l <= len; l++)
                              if (index[l] == k) alpha = val[l];
                           if (k>m)
                           {  lpx_get_col_info(lp, k-m, &tagx2, &vx2,
                                 &dx2);
                              lpx_get_col_bnds(lp, k-m, &typx2, &lb2,
                                 &ub2);
                           }
                           else
                           {  lpx_get_row_info(lp, k, &tagx2, &vx2,
                                 &dx2);
                              lpx_get_row_bnds(lp, k, &typx2, &lb2,
                                 &ub2);
                           }
                           /* Check which direction;
                              remember this is upper bound */
                           if (alpha > 0)
                              max_inc = (ub2 - vx2)/ alpha;
                           else
                              max_inc = (lb2 - vx2)/ alpha;
                        }
                        /* now check lower bound */
                        k = lpx_prim_ratio_test(lp, len, index, val, -1,
                           10e-7);
                        max_dec = DBL_MAX;
                        if (k != 0)
                        {  /*int stat;*/
                           int tagx2, typx2;
                           double vx2, dx2, lb2, ub2;
                           /*double delta;*/
                           double alpha;
                           int l;
                           for (l = 1; l <= len; l++)
                              if (index[l] == k) alpha = val[l];
                           if (k>m)
                           {  lpx_get_col_info(lp, k-m, &tagx2, &vx2,
                                 &dx2);
                              lpx_get_col_bnds(lp, k-m, &typx2, &lb2,
                                 &ub2);
                           }
                           else
                           {  lpx_get_row_info(lp, k, &tagx2, &vx2,
                                 &dx2);
                              lpx_get_row_bnds(lp, k, &typx2, &lb2,
                                 &ub2);
                           }
                           /* Check which direction;
                              remember this is lower bound */
                           if (alpha > 0)
                              max_dec = (vx2 - lb2)/ alpha;
                           else
                              max_dec = (vx2 - ub2)/ alpha;
                        }
                     }
                     /* bound */
                     if (typx == LPX_DB || typx == LPX_FX)
                     {  if (max_inc > ub - lb)
                           max_inc = ub - lb;
                     }
                     fprintf(fp, "         LOWER         %13.6g ", lb);
                     if (max_inc == -0.0) max_inc = 0.0;
                     if (max_dec == -0.0) max_dec = 0.0;
                     if (max_inc == DBL_MAX)
                        fprintf(fp, "%13s ", "infinity");
                     else if (max_inc < 1.0e-12 && max_inc > 0)
                        fprintf(fp, "%13s ", "< eps");
                     else
                        fprintf(fp, "%13.6g ", max_inc);
                     if (max_dec == DBL_MAX)
                        fprintf(fp, "%13s ", "infinity");
                     else if (max_dec < 1.0e-12 && max_dec > 0)
                        fprintf(fp, "%13s ", "< eps");
                     else
                        fprintf(fp, "%13.6g ", max_dec);
                     fprintf(fp, "\n");
                  }
                  /* now check upper bound */
                  if (typx == LPX_UP || typx == LPX_DB ||
                     typx == LPX_FX)
                  {  int at_upper;
                     at_upper = 0;
                     if (tagx == LPX_BS || tagx == LPX_NL)
                     {  max_inc = DBL_MAX;
                        max_dec = ub - vx;
                     }
                     if (tagx == LPX_NS)
                     {  max_inc = 0.0;
                        max_dec = 0.0;
                        if (dir == LPX_MIN && dx < 0) at_upper = 1;
                        if (dir == LPX_MAX && dx > 0) at_upper = 1;
                     }
                     if (tagx == LPX_NU || at_upper == 1)
                     {  int len;
                        /* we have to see how it affects basic
                           variables */
                        len = lpx_eval_tab_col(lp, what==1?ij:ij+m,
                           index, val);
                        k = lpx_prim_ratio_test(lp, len, index, val, 1,
                           10e-7);
                        max_inc = DBL_MAX;
                        if (k != 0)
                        {  /*int stat;*/
                           int tagx2, typx2;
                           double vx2, dx2, lb2, ub2;
                           /*double delta;*/
                           double alpha;
                           int l;
                           for (l = 1; l <= len; l++)
                              if (index[l] == k) alpha = val[l];
                           if (k>m)
                           {  lpx_get_col_info(lp, k-m, &tagx2, &vx2,
                                 &dx2);
                              lpx_get_col_bnds(lp, k-m, &typx2, &lb2,
                                 &ub2);
                           }
                           else
                           {  lpx_get_row_info(lp, k, &tagx2, &vx2,
                                 &dx2);
                              lpx_get_row_bnds(lp, k, &typx2, &lb2,
                                 &ub2);
                           }
                           /* Check which direction;
                              remember this is upper bound */
                           if (alpha > 0)
                              max_inc = (ub2 - vx2)/ alpha;
                           else
                              max_inc = (lb2 - vx2)/ alpha;
                        }
                        /* now check lower bound */
                        k = lpx_prim_ratio_test(lp, len, index, val, -1,
                           10e-7);
                        max_dec = DBL_MAX;
                        if (k != 0)
                        {  /*int stat;*/
                           int tagx2, typx2;
                           double vx2, dx2, lb2, ub2;
                           /*double delta;*/
                           double alpha;
                           int l;
                           for (l = 1; l <= len; l++)
                              if (index[l] == k) alpha = val[l];
                           if (k>m)
                           {  lpx_get_col_info(lp, k-m, &tagx2, &vx2,
                                 &dx2);
                              lpx_get_col_bnds(lp, k-m, &typx2, &lb2,
                                 &ub2);
                           }
                           else
                           {  lpx_get_row_info(lp, k, &tagx2, &vx2,
                                 &dx2);
                              lpx_get_row_bnds(lp, k, &typx2, &lb2,
                                 &ub2);
                           }
                           /* Check which direction;
                              remember this is lower bound */
                           if (alpha > 0)
                              max_dec = (vx2 - lb2)/ alpha;
                           else
                              max_dec = (vx2 - ub2)/ alpha;
                        }
                     }
                     if (typx == LPX_DB || typx == LPX_FX)
                     {  if (max_dec > ub - lb)
                           max_dec = ub - lb;
                     }
                     /* bound */
                     fprintf(fp, "         UPPER         %13.6g ", ub);
                     if (max_inc == -0.0) max_inc = 0.0;
                     if (max_dec == -0.0) max_dec = 0.0;
                     if (max_inc == DBL_MAX)
                        fprintf(fp, "%13s ", "infinity");
                     else if (max_inc < 1.0e-12 && max_inc > 0)
                        fprintf(fp, "%13s ", "< eps");
                     else
                        fprintf(fp, "%13.6g ", max_inc);
                     if (max_dec == DBL_MAX)
                        fprintf(fp, "%13s ", "infinity");
                     else if (max_dec < 1.0e-12 && max_dec > 0)
                        fprintf(fp, "%13s ", "< eps");
                     else
                        fprintf(fp, "%13.6g ", max_dec);
                     fprintf(fp, "\n");
                  }
               }
            }
            /* free the memory we used */
            ufree(index);
            ufree(val);
         }
         else fprintf(fp, "No range information since solution is not o"
            "ptimal.\n");
      }
      fprintf(fp, "\n");
      fprintf(fp, "End of output\n");
      fflush(fp);
      if (ferror(fp))
      {  print("lpx_print_sens_bnds: can't write to `%s' - %s", fname,
            strerror(errno));
         goto fail;
      }
      ufclose(fp);
      return 0;
fail: if (fp != NULL) ufclose(fp);
      return 1;
}