From 1a69c30feba6132ae24d5cf5995b68fb34f0fe81 Mon Sep 17 00:00:00 2001
From: hartmann <hartmann@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Wed, 22 Nov 2000 14:47:03 +0000
Subject: [PATCH] SparseMatrix<number>::n_actually_nonzero_elements () counts
 all entries that are really nonzero.

git-svn-id: https://svn.dealii.org/trunk@3496 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/lac/include/lac/sparse_matrix.h           | 14 ++++++++++++++
 deal.II/lac/include/lac/sparse_matrix.templates.h | 10 ++++++++++
 2 files changed, 24 insertions(+)

diff --git a/deal.II/lac/include/lac/sparse_matrix.h b/deal.II/lac/include/lac/sparse_matrix.h
index 3e59f49bab..57902399df 100644
--- a/deal.II/lac/include/lac/sparse_matrix.h
+++ b/deal.II/lac/include/lac/sparse_matrix.h
@@ -219,6 +219,20 @@ class SparseMatrix : public Subscriptor
 				      * be zero, it is counted anyway.
 				      */
     unsigned int n_nonzero_elements () const;
+
+				     /**
+				      * Return the number of actually
+				      * nonzero elements of this
+				      * matrix.
+				      *
+				      * Note, that this function does
+				      * (in contrary to the
+				      * @p{n_nonzero_elements}) NOT
+				      * count all entries of the
+				      * sparsity pattern but only the
+				      * ones that are nonzero.
+				      */
+    unsigned int n_actually_nonzero_elements () const;
     
 				     /**
 				      * Set the element @p{(i,j)} to @p{value}.
diff --git a/deal.II/lac/include/lac/sparse_matrix.templates.h b/deal.II/lac/include/lac/sparse_matrix.templates.h
index 40fbc14c59..1408679585 100644
--- a/deal.II/lac/include/lac/sparse_matrix.templates.h
+++ b/deal.II/lac/include/lac/sparse_matrix.templates.h
@@ -152,6 +152,16 @@ SparseMatrix<number>::n_nonzero_elements () const
 };
 
 
+template <typename number>
+unsigned int
+SparseMatrix<number>::n_actually_nonzero_elements () const
+{
+  Assert (cols != 0, ExcMatrixNotInitialized());
+  return count_if(&val[0], &val[n_nonzero_elements ()],
+		  bind2nd(not_equal_to<double>(), 0));
+};
+
+
 template <typename number>
 template <typename somenumber>
 SparseMatrix<number> &
-- 
2.39.5