diff -r d59bea55db9b -r c445c931472f src/glpapi04.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/glpapi04.c	Mon Dec 06 13:09:21 2010 +0100
@@ -0,0 +1,156 @@
+/* glpapi04.c (problem scaling routines) */
+
+/***********************************************************************
+*  This code is part of GLPK (GNU Linear Programming Kit).
+*
+*  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+*  2009, 2010 Andrew Makhorin, Department for Applied Informatics,
+*  Moscow Aviation Institute, Moscow, Russia. All rights reserved.
+*  E-mail: <mao@gnu.org>.
+*
+*  GLPK is free software: you can redistribute it and/or modify it
+*  under the terms of the GNU General Public License as published by
+*  the Free Software Foundation, either version 3 of the License, or
+*  (at your option) any later version.
+*
+*  GLPK is distributed in the hope that it will be useful, but WITHOUT
+*  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+*  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+*  License for more details.
+*
+*  You should have received a copy of the GNU General Public License
+*  along with GLPK. If not, see <http://www.gnu.org/licenses/>.
+***********************************************************************/
+
+#include "glpapi.h"
+
+/***********************************************************************
+*  NAME
+*
+*  glp_set_rii - set (change) row scale factor
+*
+*  SYNOPSIS
+*
+*  void glp_set_rii(glp_prob *lp, int i, double rii);
+*
+*  DESCRIPTION
+*
+*  The routine glp_set_rii sets (changes) the scale factor r[i,i] for
+*  i-th row of the specified problem object. */
+
+void glp_set_rii(glp_prob *lp, int i, double rii)
+{     if (!(1 <= i && i <= lp->m))
+         xerror("glp_set_rii: i = %d; row number out of range\n", i);
+      if (rii <= 0.0)
+         xerror("glp_set_rii: i = %d; rii = %g; invalid scale factor\n",
+            i, rii);
+      if (lp->valid && lp->row[i]->rii != rii)
+      {  GLPAIJ *aij;
+         for (aij = lp->row[i]->ptr; aij != NULL; aij = aij->r_next)
+         {  if (aij->col->stat == GLP_BS)
+            {  /* invalidate the basis factorization */
+               lp->valid = 0;
+               break;
+            }
+         }
+      }
+      lp->row[i]->rii = rii;
+      return;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_set sjj - set (change) column scale factor
+*
+*  SYNOPSIS
+*
+*  void glp_set_sjj(glp_prob *lp, int j, double sjj);
+*
+*  DESCRIPTION
+*
+*  The routine glp_set_sjj sets (changes) the scale factor s[j,j] for
+*  j-th column of the specified problem object. */
+
+void glp_set_sjj(glp_prob *lp, int j, double sjj)
+{     if (!(1 <= j && j <= lp->n))
+         xerror("glp_set_sjj: j = %d; column number out of range\n", j);
+      if (sjj <= 0.0)
+         xerror("glp_set_sjj: j = %d; sjj = %g; invalid scale factor\n",
+            j, sjj);
+      if (lp->valid && lp->col[j]->sjj != sjj && lp->col[j]->stat ==
+         GLP_BS)
+      {  /* invalidate the basis factorization */
+         lp->valid = 0;
+      }
+      lp->col[j]->sjj = sjj;
+      return;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_get_rii - retrieve row scale factor
+*
+*  SYNOPSIS
+*
+*  double glp_get_rii(glp_prob *lp, int i);
+*
+*  RETURNS
+*
+*  The routine glp_get_rii returns current scale factor r[i,i] for i-th
+*  row of the specified problem object. */
+
+double glp_get_rii(glp_prob *lp, int i)
+{     if (!(1 <= i && i <= lp->m))
+         xerror("glp_get_rii: i = %d; row number out of range\n", i);
+      return lp->row[i]->rii;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_get_sjj - retrieve column scale factor
+*
+*  SYNOPSIS
+*
+*  double glp_get_sjj(glp_prob *lp, int j);
+*
+*  RETURNS
+*
+*  The routine glp_get_sjj returns current scale factor s[j,j] for j-th
+*  column of the specified problem object. */
+
+double glp_get_sjj(glp_prob *lp, int j)
+{     if (!(1 <= j && j <= lp->n))
+         xerror("glp_get_sjj: j = %d; column number out of range\n", j);
+      return lp->col[j]->sjj;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_unscale_prob - unscale problem data
+*
+*  SYNOPSIS
+*
+*  void glp_unscale_prob(glp_prob *lp);
+*
+*  DESCRIPTION
+*
+*  The routine glp_unscale_prob performs unscaling of problem data for
+*  the specified problem object.
+*
+*  "Unscaling" means replacing the current scaling matrices R and S by
+*  unity matrices that cancels the scaling effect. */
+
+void glp_unscale_prob(glp_prob *lp)
+{     int m = glp_get_num_rows(lp);
+      int n = glp_get_num_cols(lp);
+      int i, j;
+      for (i = 1; i <= m; i++) glp_set_rii(lp, i, 1.0);
+      for (j = 1; j <= n; j++) glp_set_sjj(lp, j, 1.0);
+      return;
+}
+
+/* eof */