Check whether diagonals are present.

[[Imported from SVN: r695]]

istl/matrixutils.hh

@@ -5,6 +5,7 @@
 
 #include <dune/common/typetraits.hh>
 #include <dune/common/helpertemplates.hh>
+#include "istlexception.hh"
 
 namespace Dune
 {
@@ -54,6 +55,41 @@ namespace Dune
 
   }
 
+  /**
+   * @brief Check whether the a matrix has diagonal values
+   * on blocklevel recursion levels.
+   */
+  template<std::size_t blocklevel, std::size_t l=blocklevel>
+  struct CheckIfDiagonalPresent
+  {
+    /**
+     * @brief Check whether the a matrix has diagonal values
+     * on blocklevel recursion levels.
+     */
+    template<class Matrix>
+    static void check(const Matrix& mat)
+    {
+#ifdef DUNE_ISTL_WITH_CHECKING
+      CheckIfDiagonalPresent<blocklevel-1,l>::check(mat);
+#endif
+    }
+  };
+
+  template<std::size_t l>
+  struct CheckIfDiagonalPresent<0,l>
+  {
+    template<class Matrix>
+    static void check(const Matrix& mat)
+    {
+      typedef typename Matrix::ConstRowIterator Row;
+      for(Row row = mat.begin(); row!=mat.end(); ++row) {
+        if(row->find(row.index())==row->end())
+          DUNE_THROW(ISTLException, "Missing diagonal value in row "<<row.index()
+                                                                    <<" at block recursion level "<<l);
+      }
+    }
+  };
+
   /**
    * @brief Get the number of nonzero fields in the matrix.
    *

istl/preconditioners.hh

@@ -11,6 +11,7 @@
 
 #include "solvercategory.hh"
 #include "istlexception.hh"
+#include "matrixutils.hh"
 #include "io.hh"
 #include "gsetc.hh"
 #include "ilu.hh"
@@ -134,7 +135,9 @@ namespace Dune {
      */
     SeqSSOR (const M& A, int n, field_type w)
       : _A_(A), _n(n), _w(w)
-    {   }
+    {
+      CheckIfDiagonalPresent<l>::check(_A_);
+    }
 
     /*!
        \brief Prepare the preconditioner.
@@ -207,7 +210,9 @@ namespace Dune {
      */
     SeqSOR (const M& A, int n, field_type w)
       : _A_(A), _n(n), _w(w)
-    {   }
+    {
+      CheckIfDiagonalPresent<l>::check(_A_);
+    }
 
     /*!
        \brief Prepare the preconditioner.
@@ -277,7 +282,9 @@ namespace Dune {
      */
     SeqGS (const M& A, int n, field_type w)
       : _A_(A), _n(n), _w(w)
-    {   }
+    {
+      CheckIfDiagonalPresent<l>::check(_A_);
+    }
 
     /*!
        \brief Prepare the preconditioner.
@@ -347,7 +354,9 @@ namespace Dune {
      */
     SeqJac (const M& A, int n, field_type w)
       : _A_(A), _n(n), _w(w)
-    {   }
+    {
+      CheckIfDiagonalPresent<l>::check(_A_);
+    }
 
     /*!
        \brief Prepare the preconditioner.