/* glpapi11.c (utility routines) */

/***********************************************************************

*  This code is part of GLPK (GNU Linear Programming Kit).

*

*  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,

*  2009, 2010 Andrew Makhorin, Department for Applied Informatics,

*  Moscow Aviation Institute, Moscow, Russia. All rights reserved.

*  E-mail: <mao@gnu.org>.

*

*  GLPK is free software: you can redistribute it and/or modify it

*  under the terms of the GNU General Public License as published by

*  the Free Software Foundation, either version 3 of the License, or

*  (at your option) any later version.

*

*  GLPK is distributed in the hope that it will be useful, but WITHOUT

*  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

*  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public

*  License for more details.

*

*  You should have received a copy of the GNU General Public License

*  along with GLPK. If not, see <http://www.gnu.org/licenses/>.

***********************************************************************/

#include "glpapi.h"

int glp_print_sol(glp_prob *P, const char *fname)

{     /* write basic solution in printable format */

      XFILE *fp;

      GLPROW *row;

      GLPCOL *col;

      int i, j, t, ae_ind, re_ind, ret;

      double ae_max, re_max;

      xprintf("Writing basic solution to `%s'...\n", fname);

      fp = xfopen(fname, "w");

      if (fp == NULL)

      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      xfprintf(fp, "%-12s%s\n", "Problem:",

         P->name == NULL ? "" : P->name);

      xfprintf(fp, "%-12s%d\n", "Rows:", P->m);

      xfprintf(fp, "%-12s%d\n", "Columns:", P->n);

      xfprintf(fp, "%-12s%d\n", "Non-zeros:", P->nnz);

      t = glp_get_status(P);

      xfprintf(fp, "%-12s%s\n", "Status:",

         t == GLP_OPT    ? "OPTIMAL" :

         t == GLP_FEAS   ? "FEASIBLE" :

         t == GLP_INFEAS ? "INFEASIBLE (INTERMEDIATE)" :

         t == GLP_NOFEAS ? "INFEASIBLE (FINAL)" :

         t == GLP_UNBND  ? "UNBOUNDED" :

         t == GLP_UNDEF  ? "UNDEFINED" : "???");

      xfprintf(fp, "%-12s%s%s%.10g (%s)\n", "Objective:",

         P->obj == NULL ? "" : P->obj,

         P->obj == NULL ? "" : " = ", P->obj_val,

         P->dir == GLP_MIN ? "MINimum" :

         P->dir == GLP_MAX ? "MAXimum" : "???");

      xfprintf(fp, "\n");

      xfprintf(fp, "   No.   Row name   St   Activity     Lower bound  "

         " Upper bound    Marginal\n");

      xfprintf(fp, "------ ------------ -- ------------- ------------- "

         "------------- -------------\n");

      for (i = 1; i <= P->m; i++)

      {  row = P->row[i];

         xfprintf(fp, "%6d ", i);

         if (row->name == NULL || strlen(row->name) <= 12)

            xfprintf(fp, "%-12s ", row->name == NULL ? "" : row->name);

         else

            xfprintf(fp, "%s\n%20s", row->name, "");

         xfprintf(fp, "%s ",

            row->stat == GLP_BS ? "B " :

            row->stat == GLP_NL ? "NL" :

            row->stat == GLP_NU ? "NU" :

            row->stat == GLP_NF ? "NF" :

            row->stat == GLP_NS ? "NS" : "??");

         xfprintf(fp, "%13.6g ",

            fabs(row->prim) <= 1e-9 ? 0.0 : row->prim);

         if (row->type == GLP_LO || row->type == GLP_DB ||

             row->type == GLP_FX)

            xfprintf(fp, "%13.6g ", row->lb);

         else

            xfprintf(fp, "%13s ", "");

         if (row->type == GLP_UP || row->type == GLP_DB)

            xfprintf(fp, "%13.6g ", row->ub);

         else

            xfprintf(fp, "%13s ", row->type == GLP_FX ? "=" : "");

         if (row->stat != GLP_BS)

         {  if (fabs(row->dual) <= 1e-9)

               xfprintf(fp, "%13s", "< eps");

            else

               xfprintf(fp, "%13.6g ", row->dual);

         }

         xfprintf(fp, "\n");

      }

      xfprintf(fp, "\n");

      xfprintf(fp, "   No. Column name  St   Activity     Lower bound  "

         " Upper bound    Marginal\n");

      xfprintf(fp, "------ ------------ -- ------------- ------------- "

         "------------- -------------\n");

      for (j = 1; j <= P->n; j++)

      {  col = P->col[j];

         xfprintf(fp, "%6d ", j);

         if (col->name == NULL || strlen(col->name) <= 12)

            xfprintf(fp, "%-12s ", col->name == NULL ? "" : col->name);

         else

            xfprintf(fp, "%s\n%20s", col->name, "");

         xfprintf(fp, "%s ",

            col->stat == GLP_BS ? "B " :

            col->stat == GLP_NL ? "NL" :

            col->stat == GLP_NU ? "NU" :

            col->stat == GLP_NF ? "NF" :

            col->stat == GLP_NS ? "NS" : "??");

         xfprintf(fp, "%13.6g ",

            fabs(col->prim) <= 1e-9 ? 0.0 : col->prim);

         if (col->type == GLP_LO || col->type == GLP_DB ||

             col->type == GLP_FX)

            xfprintf(fp, "%13.6g ", col->lb);

         else

            xfprintf(fp, "%13s ", "");

         if (col->type == GLP_UP || col->type == GLP_DB)

            xfprintf(fp, "%13.6g ", col->ub);

         else

            xfprintf(fp, "%13s ", col->type == GLP_FX ? "=" : "");

         if (col->stat != GLP_BS)

         {  if (fabs(col->dual) <= 1e-9)

               xfprintf(fp, "%13s", "< eps");

            else

               xfprintf(fp, "%13.6g ", col->dual);

         }

         xfprintf(fp, "\n");

      }

      xfprintf(fp, "\n");

      xfprintf(fp, "Karush-Kuhn-Tucker optimality conditions:\n");

      xfprintf(fp, "\n");

      _glp_check_kkt(P, GLP_SOL, GLP_KKT_PE, &ae_max, &ae_ind, &re_max,

         &re_ind);

      xfprintf(fp, "KKT.PE: max.abs.err = %.2e on row %d\n",

         ae_max, ae_ind);

      xfprintf(fp, "        max.rel.err = %.2e on row %d\n",

         re_max, re_ind);

      xfprintf(fp, "%8s%s\n", "",

         re_max <= 1e-9 ? "High quality" :

         re_max <= 1e-6 ? "Medium quality" :

         re_max <= 1e-3 ? "Low quality" : "PRIMAL SOLUTION IS WRONG");

      xfprintf(fp, "\n");

      _glp_check_kkt(P, GLP_SOL, GLP_KKT_PB, &ae_max, &ae_ind, &re_max,

         &re_ind);

      xfprintf(fp, "KKT.PB: max.abs.err = %.2e on %s %d\n",

            ae_max, ae_ind <= P->m ? "row" : "column",

            ae_ind <= P->m ? ae_ind : ae_ind - P->m);

      xfprintf(fp, "        max.rel.err = %.2e on %s %d\n",

            re_max, re_ind <= P->m ? "row" : "column",

            re_ind <= P->m ? re_ind : re_ind - P->m);

      xfprintf(fp, "%8s%s\n", "",

         re_max <= 1e-9 ? "High quality" :

         re_max <= 1e-6 ? "Medium quality" :

         re_max <= 1e-3 ? "Low quality" : "PRIMAL SOLUTION IS INFEASIBL"

            "E");

      xfprintf(fp, "\n");

      _glp_check_kkt(P, GLP_SOL, GLP_KKT_DE, &ae_max, &ae_ind, &re_max,

         &re_ind);

      xfprintf(fp, "KKT.DE: max.abs.err = %.2e on column %d\n",

         ae_max, ae_ind == 0 ? 0 : ae_ind - P->m);

      xfprintf(fp, "        max.rel.err = %.2e on column %d\n",

         re_max, re_ind == 0 ? 0 : re_ind - P->m);

      xfprintf(fp, "%8s%s\n", "",

         re_max <= 1e-9 ? "High quality" :

         re_max <= 1e-6 ? "Medium quality" :

         re_max <= 1e-3 ? "Low quality" : "DUAL SOLUTION IS WRONG");

      xfprintf(fp, "\n");

      _glp_check_kkt(P, GLP_SOL, GLP_KKT_DB, &ae_max, &ae_ind, &re_max,

         &re_ind);

      xfprintf(fp, "KKT.DB: max.abs.err = %.2e on %s %d\n",

            ae_max, ae_ind <= P->m ? "row" : "column",

            ae_ind <= P->m ? ae_ind : ae_ind - P->m);

      xfprintf(fp, "        max.rel.err = %.2e on %s %d\n",

            re_max, re_ind <= P->m ? "row" : "column",

            re_ind <= P->m ? re_ind : re_ind - P->m);

      xfprintf(fp, "%8s%s\n", "",

         re_max <= 1e-9 ? "High quality" :

         re_max <= 1e-6 ? "Medium quality" :

         re_max <= 1e-3 ? "Low quality" : "DUAL SOLUTION IS INFEASIBLE")

            ;

      xfprintf(fp, "\n");

      xfprintf(fp, "End of output\n");

      xfflush(fp);

      if (xferror(fp))

      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      ret = 0;

done: if (fp != NULL) xfclose(fp);

      return ret;

}

/***********************************************************************

*  NAME

*

*  glp_read_sol - read basic solution from text file

*

*  SYNOPSIS

*

*  int glp_read_sol(glp_prob *lp, const char *fname);

*

*  DESCRIPTION

*

*  The routine glp_read_sol reads basic solution from a text file whose

*  name is specified by the parameter fname into the problem object.

*

*  For the file format see description of the routine glp_write_sol.

*

*  RETURNS

*

*  On success the routine returns zero, otherwise non-zero. */

int glp_read_sol(glp_prob *lp, const char *fname)

{     glp_data *data;

      jmp_buf jump;

      int i, j, k, ret = 0;

      xprintf("Reading basic solution from `%s'...\n", fname);

      data = glp_sdf_open_file(fname);

      if (data == NULL)

      {  ret = 1;

         goto done;

      }

      if (setjmp(jump))

      {  ret = 1;

         goto done;

      }

      glp_sdf_set_jump(data, jump);

      /* number of rows, number of columns */

      k = glp_sdf_read_int(data);

      if (k != lp->m)

         glp_sdf_error(data, "wrong number of rows\n");

      k = glp_sdf_read_int(data);

      if (k != lp->n)

         glp_sdf_error(data, "wrong number of columns\n");

      /* primal status, dual status, objective value */

      k = glp_sdf_read_int(data);

      if (!(k == GLP_UNDEF || k == GLP_FEAS || k == GLP_INFEAS ||

            k == GLP_NOFEAS))

         glp_sdf_error(data, "invalid primal status\n");

      lp->pbs_stat = k;

      k = glp_sdf_read_int(data);

      if (!(k == GLP_UNDEF || k == GLP_FEAS || k == GLP_INFEAS ||

            k == GLP_NOFEAS))

         glp_sdf_error(data, "invalid dual status\n");

      lp->dbs_stat = k;

      lp->obj_val = glp_sdf_read_num(data);

      /* rows (auxiliary variables) */

      for (i = 1; i <= lp->m; i++)

      {  GLPROW *row = lp->row[i];

         /* status, primal value, dual value */

         k = glp_sdf_read_int(data);

         if (!(k == GLP_BS || k == GLP_NL || k == GLP_NU ||

               k == GLP_NF || k == GLP_NS))

            glp_sdf_error(data, "invalid row status\n");

         glp_set_row_stat(lp, i, k);

         row->prim = glp_sdf_read_num(data);

         row->dual = glp_sdf_read_num(data);

      }

      /* columns (structural variables) */

      for (j = 1; j <= lp->n; j++)

      {  GLPCOL *col = lp->col[j];

         /* status, primal value, dual value */

         k = glp_sdf_read_int(data);

         if (!(k == GLP_BS || k == GLP_NL || k == GLP_NU ||

               k == GLP_NF || k == GLP_NS))

            glp_sdf_error(data, "invalid column status\n");

         glp_set_col_stat(lp, j, k);

         col->prim = glp_sdf_read_num(data);

         col->dual = glp_sdf_read_num(data);

      }

      xprintf("%d lines were read\n", glp_sdf_line(data));

done: if (ret) lp->pbs_stat = lp->dbs_stat = GLP_UNDEF;

      if (data != NULL) glp_sdf_close_file(data);

      return ret;

}

/***********************************************************************

*  NAME

*

*  glp_write_sol - write basic solution to text file

*

*  SYNOPSIS

*

*  int glp_write_sol(glp_prob *lp, const char *fname);

*

*  DESCRIPTION

*

*  The routine glp_write_sol writes the current basic solution to a

*  text file whose name is specified by the parameter fname. This file

*  can be read back with the routine glp_read_sol.

*

*  RETURNS

*

*  On success the routine returns zero, otherwise non-zero.

*

*  FILE FORMAT

*

*  The file created by the routine glp_write_sol is a plain text file,

*  which contains the following information:

*

*     m n

*     p_stat d_stat obj_val

*     r_stat[1] r_prim[1] r_dual[1]

*     . . .

*     r_stat[m] r_prim[m] r_dual[m]

*     c_stat[1] c_prim[1] c_dual[1]

*     . . .

*     c_stat[n] c_prim[n] c_dual[n]

*

*  where:

*  m is the number of rows (auxiliary variables);

*  n is the number of columns (structural variables);

*  p_stat is the primal status of the basic solution (GLP_UNDEF = 1,

*     GLP_FEAS = 2, GLP_INFEAS = 3, or GLP_NOFEAS = 4);

*  d_stat is the dual status of the basic solution (GLP_UNDEF = 1,

*     GLP_FEAS = 2, GLP_INFEAS = 3, or GLP_NOFEAS = 4);

*  obj_val is the objective value;

*  r_stat[i], i = 1,...,m, is the status of i-th row (GLP_BS = 1,

*     GLP_NL = 2, GLP_NU = 3, GLP_NF = 4, or GLP_NS = 5);

*  r_prim[i], i = 1,...,m, is the primal value of i-th row;

*  r_dual[i], i = 1,...,m, is the dual value of i-th row;

*  c_stat[j], j = 1,...,n, is the status of j-th column (GLP_BS = 1,

*     GLP_NL = 2, GLP_NU = 3, GLP_NF = 4, or GLP_NS = 5);

*  c_prim[j], j = 1,...,n, is the primal value of j-th column;

*  c_dual[j], j = 1,...,n, is the dual value of j-th column. */

int glp_write_sol(glp_prob *lp, const char *fname)

{     XFILE *fp;

      int i, j, ret = 0;

      xprintf("Writing basic solution to `%s'...\n", fname);

      fp = xfopen(fname, "w");

      if (fp == NULL)

      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      /* number of rows, number of columns */

      xfprintf(fp, "%d %d\n", lp->m, lp->n);

      /* primal status, dual status, objective value */

      xfprintf(fp, "%d %d %.*g\n", lp->pbs_stat, lp->dbs_stat, DBL_DIG,

         lp->obj_val);

      /* rows (auxiliary variables) */

      for (i = 1; i <= lp->m; i++)

      {  GLPROW *row = lp->row[i];

         /* status, primal value, dual value */

         xfprintf(fp, "%d %.*g %.*g\n", row->stat, DBL_DIG, row->prim,

            DBL_DIG, row->dual);

      }

      /* columns (structural variables) */

      for (j = 1; j <= lp->n; j++)

      {  GLPCOL *col = lp->col[j];

         /* status, primal value, dual value */

         xfprintf(fp, "%d %.*g %.*g\n", col->stat, DBL_DIG, col->prim,

            DBL_DIG, col->dual);

      }

      xfflush(fp);

      if (xferror(fp))

      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      xprintf("%d lines were written\n", 2 + lp->m + lp->n);

done: if (fp != NULL) xfclose(fp);

      return ret;

}

/**********************************************************************/

static char *format(char buf[13+1], double x)

{     /* format floating-point number in MPS/360-like style */

      if (x == -DBL_MAX)

         strcpy(buf, "         -Inf");

      else if (x == +DBL_MAX)

         strcpy(buf, "         +Inf");

      else if (fabs(x) <= 999999.99998)

      {  sprintf(buf, "%13.5f", x);

#if 1

         if (strcmp(buf, "      0.00000") == 0 ||

             strcmp(buf, "     -0.00000") == 0)

            strcpy(buf, "       .     ");

         else if (memcmp(buf, "      0.", 8) == 0)

            memcpy(buf, "       .", 8);

         else if (memcmp(buf, "     -0.", 8) == 0)

            memcpy(buf, "      -.", 8);

#endif

      }

      else

         sprintf(buf, "%13.6g", x);

      return buf;

}

int glp_print_ranges(glp_prob *P, int len, const int list[],

      int flags, const char *fname)

{     /* print sensitivity analysis report */

      XFILE *fp = NULL;

      GLPROW *row;

      GLPCOL *col;

      int m, n, pass, k, t, numb, type, stat, var1, var2, count, page,

         ret;

      double lb, ub, slack, coef, prim, dual, value1, value2, coef1,

         coef2, obj1, obj2;

      const char *name, *limit;

      char buf[13+1];

      /* sanity checks */

      if (P == NULL || P->magic != GLP_PROB_MAGIC)

         xerror("glp_print_ranges: P = %p; invalid problem object\n",

            P);

      m = P->m, n = P->n;

      if (len < 0)

         xerror("glp_print_ranges: len = %d; invalid list length\n",

            len);

      if (len > 0)

      {  if (list == NULL)

            xerror("glp_print_ranges: list = %p: invalid parameter\n",

               list);

         for (t = 1; t <= len; t++)

         {  k = list[t];

            if (!(1 <= k && k <= m+n))

               xerror("glp_print_ranges: list[%d] = %d; row/column numb"

                  "er out of range\n", t, k);

         }

      }

      if (flags != 0)

         xerror("glp_print_ranges: flags = %d; invalid parameter\n",

            flags);

      if (fname == NULL)

         xerror("glp_print_ranges: fname = %p; invalid parameter\n",

            fname);

      if (glp_get_status(P) != GLP_OPT)

      {  xprintf("glp_print_ranges: optimal basic solution required\n");

         ret = 1;

         goto done;

      }

      if (!glp_bf_exists(P))

      {  xprintf("glp_print_ranges: basis factorization required\n");

         ret = 2;

         goto done;

      }

      /* start reporting */

      xprintf("Write sensitivity analysis report to `%s'...\n", fname);

      fp = xfopen(fname, "w");

      if (fp == NULL)

      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());

         ret = 3;

         goto done;

      }

      page = count = 0;

      for (pass = 1; pass <= 2; pass++)

      for (t = 1; t <= (len == 0 ? m+n : len); t++)

      {  if (t == 1) count = 0;

         k = (len == 0 ? t : list[t]);

         if (pass == 1 && k > m || pass == 2 && k <= m)

            continue;

         if (count == 0)

         {  xfprintf(fp, "GLPK %-4s - SENSITIVITY ANALYSIS REPORT%73sPa"

               "ge%4d\n", glp_version(), "", ++page);

            xfprintf(fp, "\n");

            xfprintf(fp, "%-12s%s\n", "Problem:",

               P->name == NULL ? "" : P->name);

            xfprintf(fp, "%-12s%s%s%.10g (%s)\n", "Objective:",

               P->obj == NULL ? "" : P->obj,

               P->obj == NULL ? "" : " = ", P->obj_val,

               P->dir == GLP_MIN ? "MINimum" :

               P->dir == GLP_MAX ? "MAXimum" : "???");

            xfprintf(fp, "\n");

            xfprintf(fp, "%6s %-12s %2s %13s %13s %13s  %13s %13s %13s "

               "%s\n", "No.", pass == 1 ? "Row name" : "Column name",

               "St", "Activity", pass == 1 ? "Slack" : "Obj coef",

               "Lower bound", "Activity", "Obj coef", "Obj value at",

               "Limiting");

            xfprintf(fp, "%6s %-12s %2s %13s %13s %13s  %13s %13s %13s "

               "%s\n", "", "", "", "", "Marginal", "Upper bound",

               "range", "range", "break point", "variable");

            xfprintf(fp, "------ ------------ -- ------------- --------"

               "----- -------------  ------------- ------------- ------"

               "------- ------------\n");

         }

         if (pass == 1)

         {  numb = k;

            xassert(1 <= numb && numb <= m);

            row = P->row[numb];

            name = row->name;

            type = row->type;

            lb = glp_get_row_lb(P, numb);

            ub = glp_get_row_ub(P, numb);

            coef = 0.0;

            stat = row->stat;

            prim = row->prim;

            if (type == GLP_FR)

               slack = - prim;

            else if (type == GLP_LO)

               slack = lb - prim;

            else if (type == GLP_UP || type == GLP_DB || type == GLP_FX)

               slack = ub - prim;

            dual = row->dual;

         }

         else

         {  numb = k - m;

            xassert(1 <= numb && numb <= n);

            col = P->col[numb];

            name = col->name;

            lb = glp_get_col_lb(P, numb);

            ub = glp_get_col_ub(P, numb);

            coef = col->coef;

            stat = col->stat;

            prim = col->prim;

            slack = 0.0;

            dual = col->dual;

         }

         if (stat != GLP_BS)

         {  glp_analyze_bound(P, k, &value1, &var1, &value2, &var2);

            if (stat == GLP_NF)

               coef1 = coef2 = coef;

            else if (stat == GLP_NS)

               coef1 = -DBL_MAX, coef2 = +DBL_MAX;

            else if (stat == GLP_NL && P->dir == GLP_MIN ||

                     stat == GLP_NU && P->dir == GLP_MAX)

               coef1 = coef - dual, coef2 = +DBL_MAX;

            else

               coef1 = -DBL_MAX, coef2 = coef - dual;

            if (value1 == -DBL_MAX)

            {  if (dual < -1e-9)

                  obj1 = +DBL_MAX;

               else if (dual > +1e-9)

                  obj1 = -DBL_MAX;

               else

                  obj1 = P->obj_val;

            }

            else

               obj1 = P->obj_val + dual * (value1 - prim);

            if (value2 == +DBL_MAX)

            {  if (dual < -1e-9)

                  obj2 = -DBL_MAX;

               else if (dual > +1e-9)

                  obj2 = +DBL_MAX;

               else

                  obj2 = P->obj_val;

            }

            else

               obj2 = P->obj_val + dual * (value2 - prim);

         }

         else

         {  glp_analyze_coef(P, k, &coef1, &var1, &value1, &coef2,

               &var2, &value2);

            if (coef1 == -DBL_MAX)

            {  if (prim < -1e-9)

                  obj1 = +DBL_MAX;

               else if (prim > +1e-9)

                  obj1 = -DBL_MAX;

               else

                  obj1 = P->obj_val;

            }

            else

               obj1 = P->obj_val + (coef1 - coef) * prim;

            if (coef2 == +DBL_MAX)

            {  if (prim < -1e-9)

                  obj2 = -DBL_MAX;

               else if (prim > +1e-9)

                  obj2 = +DBL_MAX;

               else

                  obj2 = P->obj_val;

            }

            else

               obj2 = P->obj_val + (coef2 - coef) * prim;

         }

         /*** first line ***/

         /* row/column number */

         xfprintf(fp, "%6d", numb);

         /* row/column name */

         xfprintf(fp, " %-12.12s", name == NULL ? "" : name);

         if (name != NULL && strlen(name) > 12)

            xfprintf(fp, "%s\n%6s %12s", name+12, "", "");

         /* row/column status */

         xfprintf(fp, " %2s",

            stat == GLP_BS ? "BS" : stat == GLP_NL ? "NL" :

            stat == GLP_NU ? "NU" : stat == GLP_NF ? "NF" :

            stat == GLP_NS ? "NS" : "??");

         /* row/column activity */

         xfprintf(fp, " %s", format(buf, prim));

         /* row slack, column objective coefficient */

         xfprintf(fp, " %s", format(buf, k <= m ? slack : coef));

         /* row/column lower bound */

         xfprintf(fp, " %s", format(buf, lb));

         /* row/column activity range */

         xfprintf(fp, "  %s", format(buf, value1));

         /* row/column objective coefficient range */

         xfprintf(fp, " %s", format(buf, coef1));

         /* objective value at break point */

         xfprintf(fp, " %s", format(buf, obj1));

         /* limiting variable name */

         if (var1 != 0)

         {  if (var1 <= m)

               limit = glp_get_row_name(P, var1);

            else

               limit = glp_get_col_name(P, var1 - m);

            if (limit != NULL)

               xfprintf(fp, " %s", limit);

         }

         xfprintf(fp, "\n");

         /*** second line ***/

         xfprintf(fp, "%6s %-12s %2s %13s", "", "", "", "");

         /* row/column reduced cost */

         xfprintf(fp, " %s", format(buf, dual));

         /* row/column upper bound */

         xfprintf(fp, " %s", format(buf, ub));

         /* row/column activity range */

         xfprintf(fp, "  %s", format(buf, value2));

         /* row/column objective coefficient range */

         xfprintf(fp, " %s", format(buf, coef2));

         /* objective value at break point */

         xfprintf(fp, " %s", format(buf, obj2));

         /* limiting variable name */

         if (var2 != 0)

         {  if (var2 <= m)

               limit = glp_get_row_name(P, var2);

            else

               limit = glp_get_col_name(P, var2 - m);

            if (limit != NULL)

               xfprintf(fp, " %s", limit);

         }

         xfprintf(fp, "\n");

         xfprintf(fp, "\n");

         /* print 10 items per page */

         count = (count + 1) % 10;

      }

      xfprintf(fp, "End of report\n");

      xfflush(fp);

      if (xferror(fp))

      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());

         ret = 4;

         goto done;

      }

      ret = 0;

done: if (fp != NULL) xfclose(fp);

      return ret;

}

/**********************************************************************/

int glp_print_ipt(glp_prob *P, const char *fname)

{     /* write interior-point solution in printable format */

      XFILE *fp;

      GLPROW *row;

      GLPCOL *col;

      int i, j, t, ae_ind, re_ind, ret;

      double ae_max, re_max;

      xprintf("Writing interior-point solution to `%s'...\n", fname);

      fp = xfopen(fname, "w");

      if (fp == NULL)

      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      xfprintf(fp, "%-12s%s\n", "Problem:",

         P->name == NULL ? "" : P->name);

      xfprintf(fp, "%-12s%d\n", "Rows:", P->m);

      xfprintf(fp, "%-12s%d\n", "Columns:", P->n);

      xfprintf(fp, "%-12s%d\n", "Non-zeros:", P->nnz);

      t = glp_ipt_status(P);

      xfprintf(fp, "%-12s%s\n", "Status:",

         t == GLP_OPT    ? "OPTIMAL" :

         t == GLP_UNDEF  ? "UNDEFINED" :

         t == GLP_INFEAS ? "INFEASIBLE (INTERMEDIATE)" :

         t == GLP_NOFEAS ? "INFEASIBLE (FINAL)" : "???");

      xfprintf(fp, "%-12s%s%s%.10g (%s)\n", "Objective:",

         P->obj == NULL ? "" : P->obj,

         P->obj == NULL ? "" : " = ", P->ipt_obj,

         P->dir == GLP_MIN ? "MINimum" :

         P->dir == GLP_MAX ? "MAXimum" : "???");

      xfprintf(fp, "\n");

      xfprintf(fp, "   No.   Row name        Activity     Lower bound  "

         " Upper bound    Marginal\n");

      xfprintf(fp, "------ ------------    ------------- ------------- "

         "------------- -------------\n");

      for (i = 1; i <= P->m; i++)

      {  row = P->row[i];

         xfprintf(fp, "%6d ", i);

         if (row->name == NULL || strlen(row->name) <= 12)

            xfprintf(fp, "%-12s ", row->name == NULL ? "" : row->name);

         else

            xfprintf(fp, "%s\n%20s", row->name, "");

         xfprintf(fp, "%3s", "");

         xfprintf(fp, "%13.6g ",

            fabs(row->pval) <= 1e-9 ? 0.0 : row->pval);

         if (row->type == GLP_LO || row->type == GLP_DB ||

             row->type == GLP_FX)

            xfprintf(fp, "%13.6g ", row->lb);

         else

            xfprintf(fp, "%13s ", "");

         if (row->type == GLP_UP || row->type == GLP_DB)

            xfprintf(fp, "%13.6g ", row->ub);

         else

            xfprintf(fp, "%13s ", row->type == GLP_FX ? "=" : "");

         if (fabs(row->dval) <= 1e-9)

            xfprintf(fp, "%13s", "< eps");

         else

            xfprintf(fp, "%13.6g ", row->dval);

         xfprintf(fp, "\n");

      }

      xfprintf(fp, "\n");

      xfprintf(fp, "   No. Column name       Activity     Lower bound  "

         " Upper bound    Marginal\n");

      xfprintf(fp, "------ ------------    ------------- ------------- "

         "------------- -------------\n");

      for (j = 1; j <= P->n; j++)

      {  col = P->col[j];

         xfprintf(fp, "%6d ", j);

         if (col->name == NULL || strlen(col->name) <= 12)

            xfprintf(fp, "%-12s ", col->name == NULL ? "" : col->name);

         else

            xfprintf(fp, "%s\n%20s", col->name, "");

         xfprintf(fp, "%3s", "");

         xfprintf(fp, "%13.6g ",

            fabs(col->pval) <= 1e-9 ? 0.0 : col->pval);

         if (col->type == GLP_LO || col->type == GLP_DB ||

             col->type == GLP_FX)

            xfprintf(fp, "%13.6g ", col->lb);

         else

            xfprintf(fp, "%13s ", "");

         if (col->type == GLP_UP || col->type == GLP_DB)

            xfprintf(fp, "%13.6g ", col->ub);

         else

            xfprintf(fp, "%13s ", col->type == GLP_FX ? "=" : "");

         if (fabs(col->dval) <= 1e-9)

            xfprintf(fp, "%13s", "< eps");

         else

            xfprintf(fp, "%13.6g ", col->dval);

         xfprintf(fp, "\n");

      }

      xfprintf(fp, "\n");

      xfprintf(fp, "Karush-Kuhn-Tucker optimality conditions:\n");

      xfprintf(fp, "\n");

      _glp_check_kkt(P, GLP_IPT, GLP_KKT_PE, &ae_max, &ae_ind, &re_max,

         &re_ind);

      xfprintf(fp, "KKT.PE: max.abs.err = %.2e on row %d\n",

         ae_max, ae_ind);

      xfprintf(fp, "        max.rel.err = %.2e on row %d\n",

         re_max, re_ind);

      xfprintf(fp, "%8s%s\n", "",

         re_max <= 1e-9 ? "High quality" :

         re_max <= 1e-6 ? "Medium quality" :

         re_max <= 1e-3 ? "Low quality" : "PRIMAL SOLUTION IS WRONG");

      xfprintf(fp, "\n");

      _glp_check_kkt(P, GLP_IPT, GLP_KKT_PB, &ae_max, &ae_ind, &re_max,

         &re_ind);

      xfprintf(fp, "KKT.PB: max.abs.err = %.2e on %s %d\n",

            ae_max, ae_ind <= P->m ? "row" : "column",

            ae_ind <= P->m ? ae_ind : ae_ind - P->m);

      xfprintf(fp, "        max.rel.err = %.2e on %s %d\n",

            re_max, re_ind <= P->m ? "row" : "column",

            re_ind <= P->m ? re_ind : re_ind - P->m);

      xfprintf(fp, "%8s%s\n", "",

         re_max <= 1e-9 ? "High quality" :

         re_max <= 1e-6 ? "Medium quality" :

         re_max <= 1e-3 ? "Low quality" : "PRIMAL SOLUTION IS INFEASIBL"

            "E");

      xfprintf(fp, "\n");

      _glp_check_kkt(P, GLP_IPT, GLP_KKT_DE, &ae_max, &ae_ind, &re_max,

         &re_ind);

      xfprintf(fp, "KKT.DE: max.abs.err = %.2e on column %d\n",

         ae_max, ae_ind == 0 ? 0 : ae_ind - P->m);

      xfprintf(fp, "        max.rel.err = %.2e on column %d\n",

         re_max, re_ind == 0 ? 0 : re_ind - P->m);

      xfprintf(fp, "%8s%s\n", "",

         re_max <= 1e-9 ? "High quality" :

         re_max <= 1e-6 ? "Medium quality" :

         re_max <= 1e-3 ? "Low quality" : "DUAL SOLUTION IS WRONG");

      xfprintf(fp, "\n");

      _glp_check_kkt(P, GLP_IPT, GLP_KKT_DB, &ae_max, &ae_ind, &re_max,

         &re_ind);

      xfprintf(fp, "KKT.DB: max.abs.err = %.2e on %s %d\n",

            ae_max, ae_ind <= P->m ? "row" : "column",

            ae_ind <= P->m ? ae_ind : ae_ind - P->m);

      xfprintf(fp, "        max.rel.err = %.2e on %s %d\n",

            re_max, re_ind <= P->m ? "row" : "column",

            re_ind <= P->m ? re_ind : re_ind - P->m);

      xfprintf(fp, "%8s%s\n", "",

         re_max <= 1e-9 ? "High quality" :

         re_max <= 1e-6 ? "Medium quality" :

         re_max <= 1e-3 ? "Low quality" : "DUAL SOLUTION IS INFEASIBLE")

            ;

      xfprintf(fp, "\n");

      xfprintf(fp, "End of output\n");

      xfflush(fp);

      if (xferror(fp))

      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      ret = 0;

done: if (fp != NULL) xfclose(fp);

      return ret;

}

/***********************************************************************

*  NAME

*

*  glp_read_ipt - read interior-point solution from text file

*

*  SYNOPSIS

*

*  int glp_read_ipt(glp_prob *lp, const char *fname);

*

*  DESCRIPTION

*

*  The routine glp_read_ipt reads interior-point solution from a text

*  file whose name is specified by the parameter fname into the problem

*  object.

*

*  For the file format see description of the routine glp_write_ipt.

*

*  RETURNS

*

*  On success the routine returns zero, otherwise non-zero. */

int glp_read_ipt(glp_prob *lp, const char *fname)

{     glp_data *data;

      jmp_buf jump;

      int i, j, k, ret = 0;

      xprintf("Reading interior-point solution from `%s'...\n", fname);

      data = glp_sdf_open_file(fname);

      if (data == NULL)

      {  ret = 1;

         goto done;

      }

      if (setjmp(jump))

      {  ret = 1;

         goto done;

      }

      glp_sdf_set_jump(data, jump);

      /* number of rows, number of columns */

      k = glp_sdf_read_int(data);

      if (k != lp->m)

         glp_sdf_error(data, "wrong number of rows\n");

      k = glp_sdf_read_int(data);

      if (k != lp->n)

         glp_sdf_error(data, "wrong number of columns\n");

      /* solution status, objective value */

      k = glp_sdf_read_int(data);

      if (!(k == GLP_UNDEF || k == GLP_OPT))

         glp_sdf_error(data, "invalid solution status\n");

      lp->ipt_stat = k;

      lp->ipt_obj = glp_sdf_read_num(data);

      /* rows (auxiliary variables) */

      for (i = 1; i <= lp->m; i++)

      {  GLPROW *row = lp->row[i];

         /* primal value, dual value */

         row->pval = glp_sdf_read_num(data);

         row->dval = glp_sdf_read_num(data);

      }

      /* columns (structural variables) */

      for (j = 1; j <= lp->n; j++)

      {  GLPCOL *col = lp->col[j];

         /* primal value, dual value */

         col->pval = glp_sdf_read_num(data);

         col->dval = glp_sdf_read_num(data);

      }

      xprintf("%d lines were read\n", glp_sdf_line(data));

done: if (ret) lp->ipt_stat = GLP_UNDEF;

      if (data != NULL) glp_sdf_close_file(data);

      return ret;

}

/***********************************************************************

*  NAME

*

*  glp_write_ipt - write interior-point solution to text file

*

*  SYNOPSIS

*

*  int glp_write_ipt(glp_prob *lp, const char *fname);

*

*  DESCRIPTION

*

*  The routine glp_write_ipt writes the current interior-point solution

*  to a text file whose name is specified by the parameter fname. This

*  file can be read back with the routine glp_read_ipt.

*

*  RETURNS

*

*  On success the routine returns zero, otherwise non-zero.

*

*  FILE FORMAT

*

*  The file created by the routine glp_write_ipt is a plain text file,

*  which contains the following information:

*

*     m n

*     stat obj_val

*     r_prim[1] r_dual[1]

*     . . .

*     r_prim[m] r_dual[m]

*     c_prim[1] c_dual[1]

*     . . .

*     c_prim[n] c_dual[n]

*

*  where:

*  m is the number of rows (auxiliary variables);

*  n is the number of columns (structural variables);

*  stat is the solution status (GLP_UNDEF = 1 or GLP_OPT = 5);

*  obj_val is the objective value;

*  r_prim[i], i = 1,...,m, is the primal value of i-th row;

*  r_dual[i], i = 1,...,m, is the dual value of i-th row;

*  c_prim[j], j = 1,...,n, is the primal value of j-th column;

*  c_dual[j], j = 1,...,n, is the dual value of j-th column. */

int glp_write_ipt(glp_prob *lp, const char *fname)

{     XFILE *fp;

      int i, j, ret = 0;

      xprintf("Writing interior-point solution to `%s'...\n", fname);

      fp = xfopen(fname, "w");

      if (fp == NULL)

      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      /* number of rows, number of columns */

      xfprintf(fp, "%d %d\n", lp->m, lp->n);

      /* solution status, objective value */

      xfprintf(fp, "%d %.*g\n", lp->ipt_stat, DBL_DIG, lp->ipt_obj);

      /* rows (auxiliary variables) */

      for (i = 1; i <= lp->m; i++)

      {  GLPROW *row = lp->row[i];

         /* primal value, dual value */

         xfprintf(fp, "%.*g %.*g\n", DBL_DIG, row->pval, DBL_DIG,

            row->dval);

      }

      /* columns (structural variables) */

      for (j = 1; j <= lp->n; j++)

      {  GLPCOL *col = lp->col[j];

         /* primal value, dual value */

         xfprintf(fp, "%.*g %.*g\n", DBL_DIG, col->pval, DBL_DIG,

            col->dval);

      }

      xfflush(fp);

      if (xferror(fp))

      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      xprintf("%d lines were written\n", 2 + lp->m + lp->n);

done: if (fp != NULL) xfclose(fp);

      return ret;

}

/**********************************************************************/

int glp_print_mip(glp_prob *P, const char *fname)

{     /* write MIP solution in printable format */

      XFILE *fp;

      GLPROW *row;

      GLPCOL *col;

      int i, j, t, ae_ind, re_ind, ret;

      double ae_max, re_max;

      xprintf("Writing MIP solution to `%s'...\n", fname);

      fp = xfopen(fname, "w");

      if (fp == NULL)

      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());

         ret = 1;

         goto done;

      }

      xfprintf(fp, "%-12s%s\n", "Problem:",

         P->name == NULL ? "" : P->name);

      xfprintf(fp, "%-12s%d\n", "Rows:", P->m);

      xfprintf(fp, "%-12s%d (%d integer, %d binary)\n", "Columns:",

         P->n, glp_get_num_int(P), glp_get_num_bin(P));

      xfprintf(fp, "%-12s%d\n", "Non-zeros:", P->nnz);

      t = glp_mip_status(P);

      xfprintf(fp, "%-12s%s\n", "Status:",

         t == GLP_OPT    ? "INTEGER OPTIMAL" :

         t == GLP_FEAS   ? "INTEGER NON-OPTIMAL" :

         t == GLP_NOFEAS ? "INTEGER EMPTY" :

         t == GLP_UNDEF  ? "INTEGER UNDEFINED" : "???");

      xfprintf(fp, "%-12s%s%s%.10g (%s)\n", "Objective:",

         P->obj == NULL ? "" : P->obj,

         P->obj == NULL ? "" : " = ", P->mip_obj,

         P->dir == GLP_MIN ? "MINimum" :

         P->dir == GLP_MAX ? "MAXimum" : "???");

      xfprintf(fp, "\n");

      xfprintf(fp, "   No.   Row name        Activity     Lower bound  "

         " Upper bound\n");

      xfprintf(fp, "------ ------------    ------------- ------------- "

         "-------------\n");

      for (i = 1; i <= P->m; i++)

      {  row = P->row[i];

         xfprintf(fp, "%6d ", i);

         if (row->name == NULL || strlen(row->name) <= 12)

            xfprintf(fp, "%-12s ", row->name == NULL ? "" : row->name);

         else