1 files changed, 135 insertions, 0 deletions
diff --git a/glpk-5.0/src/misc/fvs.c b/glpk-5.0/src/misc/fvs.c
new file mode 100644
index 0000000..1b5f04b
--- /dev/null
+++ b/glpk-5.0/src/misc/fvs.c
@@ -0,0 +1,135 @@
+/* fvs.c (sparse vector in FVS format) */
+
+/***********************************************************************
+*  This code is part of GLPK (GNU Linear Programming Kit).
+*  Copyright (C) 2016 Free Software Foundation, Inc.
+*  Written by Andrew Makhorin <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 "env.h"
+#include "fvs.h"
+
+void fvs_alloc_vec(FVS *x, int n)
+{     /* allocate sparse vector */
+      int j;
+      xassert(n >= 0);
+      x->n = n;
+      x->nnz = 0;
+      x->ind = talloc(1+n, int);
+      x->vec = talloc(1+n, double);
+      for (j = 1; j <= n; j++)
+         x->vec[j] = 0.0;
+      return;
+}
+
+void fvs_check_vec(const FVS *x)
+{     /* check sparse vector */
+      /* NOTE: for testing/debugging only */
+      int n = x->n;
+      int nnz = x->nnz;
+      int *ind = x->ind;
+      double *vec = x->vec;
+      char *map;
+      int j, k;
+      xassert(n >= 0);
+      xassert(0 <= nnz && nnz <= n);
+      map = talloc(1+n, char);
+      for (j = 1; j <= n; j++)
+         map[j] = (vec[j] != 0.0);
+      for (k = 1; k <= nnz; k++)
+      {  j = ind[k];
+         xassert(1 <= j && j <= n);
+         xassert(map[j]);
+         map[j] = 0;
+      }
+      for (j = 1; j <= n; j++)
+         xassert(!map[j]);
+      tfree(map);
+      return;
+}
+
+void fvs_gather_vec(FVS *x, double eps)
+{     /* gather sparse vector */
+      int n = x->n;
+      int *ind = x->ind;
+      double *vec = x->vec;
+      int j, nnz = 0;
+      for (j = n; j >= 1; j--)
+      {  if (-eps < vec[j] && vec[j] < +eps)
+            vec[j] = 0.0;
+         else
+            ind[++nnz] = j;
+      }
+      x->nnz = nnz;
+      return;
+}
+
+void fvs_clear_vec(FVS *x)
+{     /* clear sparse vector */
+      int *ind = x->ind;
+      double *vec = x->vec;
+      int k;
+      for (k = x->nnz; k >= 1; k--)
+         vec[ind[k]] = 0.0;
+      x->nnz = 0;
+      return;
+}
+
+void fvs_copy_vec(FVS *x, const FVS *y)
+{     /* copy sparse vector */
+      int *x_ind = x->ind;
+      double *x_vec = x->vec;
+      int *y_ind = y->ind;
+      double *y_vec = y->vec;
+      int j, k;
+      xassert(x != y);
+      xassert(x->n == y->n);
+      fvs_clear_vec(x);
+      for (k = x->nnz = y->nnz; k >= 1; k--)
+      {  j = x_ind[k] = y_ind[k];
+         x_vec[j] = y_vec[j];
+      }
+      return;
+}
+
+void fvs_adjust_vec(FVS *x, double eps)
+{     /* replace tiny vector elements by exact zeros */
+      int nnz = x->nnz;
+      int *ind = x->ind;
+      double *vec = x->vec;
+      int j, k, cnt = 0;
+      for (k = 1; k <= nnz; k++)
+      {  j = ind[k];
+         if (-eps < vec[j] && vec[j] < +eps)
+            vec[j] = 0.0;
+         else
+            ind[++cnt] = j;
+      }
+      x->nnz = cnt;
+      return;
+}
+
+void fvs_free_vec(FVS *x)
+{     /* deallocate sparse vector */
+      tfree(x->ind);
+      tfree(x->vec);
+      x->n = x->nnz = -1;
+      x->ind = NULL;
+      x->vec = NULL;
+      return;
+}
+
+/* eof */