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+/* MOD2CONVERT.C - Routines converting between sparse and dense mod2 matrices.*/
+
+/* Copyright (c) 1995-2012 by Radford M. Neal.
+ *
+ * Permission is granted for anyone to copy, use, modify, and distribute
+ * these programs and accompanying documents for any purpose, provided
+ * this copyright notice is retained and prominently displayed, and note
+ * is made of any changes made to these programs.  These programs and
+ * documents are distributed without any warranty, express or implied.
+ * As the programs were written for research purposes only, they have not
+ * been tested to the degree that would be advisable in any important
+ * application.  All use of these programs is entirely at the user's own
+ * risk.
+ */
+
+
+/* NOTE:  See mod2convert.html for documentation on these procedures. */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+
+#include "mod2dense.h"
+#include "mod2sparse.h"
+#include "mod2convert.h"
+
+
+/* CONVERT A MOD2 MATRIX FROM SPARSE TO DENSE FORM.  */
+
+void mod2sparse_to_dense 
+( mod2sparse *m, 	/* Sparse matrix to convert */
+  mod2dense *r		/* Place to store result */
+)
+{
+  mod2entry *e;
+  int i;
+
+  if (mod2sparse_rows(m)>mod2dense_rows(r) 
+   || mod2sparse_cols(m)>mod2dense_cols(r))
+  { fprintf(stderr,
+      "mod2sparse_to_dense: Dimension of result matrix is less than source\n");
+    exit(1);
+  }
+
+  mod2dense_clear(r);
+
+  for (i = 0; i<mod2sparse_rows(m); i++)
+  { e = mod2sparse_first_in_row(m,i);
+    while (!mod2sparse_at_end(e))
+    { mod2dense_set(r,i,mod2sparse_col(e),1);
+      e = mod2sparse_next_in_row(e);
+    }
+  }
+}
+
+
+/* CONVERT A MOD2 MATRIX FROM DENSE TO SPARSE FORM.  */
+
+void mod2dense_to_sparse 
+( mod2dense *m, 	/* Dense matrix to convert */
+  mod2sparse *r		/* Place to store result */
+)
+{
+  int i, j;
+
+  if (mod2dense_rows(m)>mod2sparse_rows(r) 
+   || mod2dense_cols(m)>mod2sparse_cols(r))
+  { fprintf(stderr,
+      "mod2dense_to_sparse: Dimension of result matrix is less than source\n");
+    exit(1);
+  }
+
+  mod2sparse_clear(r);
+
+  for (i = 0; i<mod2dense_rows(m); i++)
+  { for (j = 0; j<mod2dense_cols(m); j++)
+    { if (mod2dense_get(m,i,j))
+      { mod2sparse_insert(r,i,j);
+      }
+    }
+  }
+}