--- /dev/null
+//---------------------------- vector_57.cc ---------------------------
+// $Id$
+// Version: $Name$
+//
+// Copyright (C) 2004 by the deal.II authors
+//
+// This file is subject to QPL and may not be distributed
+// without copyright and license information. Please refer
+// to the file deal.II/doc/license.html for the text and
+// further information on this license.
+//
+//---------------------------- vector_57.cc ---------------------------
+
+
+// check Vector::is_non_zero
+
+#include "../tests.h"
+#include <lac/vector.h>
+#include <fstream>
+#include <iostream>
+#include <vector>
+
+
+void test (Vector<double> &v)
+{
+ // set only certain elements of the
+ // vector. they are all positive
+ std::vector<bool> pattern (v.size(), false);
+ for (unsigned int i=0; i<v.size(); i+=1+i)
+ {
+ v(i) += i;
+ pattern[i] = true;
+ }
+
+ v.compress ();
+
+ // check that the vector is really
+ // non-negative
+ Assert (v.is_non_negative() == true, ExcInternalError());
+
+ // then set a single element to a negative
+ // value and check again
+ v(v.size()/2) = -1;
+ Assert (v.is_non_negative() == false, ExcInternalError());
+
+ deallog << "OK" << std::endl;
+}
+
+
+
+int main ()
+{
+ std::ofstream logfile("vector_57.output");
+ deallog.attach(logfile);
+ deallog.depth_console(0);
+
+ try
+ {
+ Vector<double> v (100);
+ test (v);
+ }
+ catch (std::exception &exc)
+ {
+ std::cerr << std::endl << std::endl
+ << "----------------------------------------------------"
+ << std::endl;
+ std::cerr << "Exception on processing: " << std::endl
+ << exc.what() << std::endl
+ << "Aborting!" << std::endl
+ << "----------------------------------------------------"
+ << std::endl;
+
+ return 1;
+ }
+ catch (...)
+ {
+ std::cerr << std::endl << std::endl
+ << "----------------------------------------------------"
+ << std::endl;
+ std::cerr << "Unknown exception!" << std::endl
+ << "Aborting!" << std::endl
+ << "----------------------------------------------------"
+ << std::endl;
+ return 1;
+ };
+}