Index: src/Jobs/Grid/unittests/SamplingGridUnitTest.cpp
===================================================================
--- src/Jobs/Grid/unittests/SamplingGridUnitTest.cpp	(revision c889b7d07d4553e5cc902de0cd0de8fd90e0c533)
+++ src/Jobs/Grid/unittests/SamplingGridUnitTest.cpp	(revision c889b7d07d4553e5cc902de0cd0de8fd90e0c533)
@@ -0,0 +1,152 @@
+/*
+ * Project: MoleCuilder
+ * Description: creates and alters molecular systems
+ * Copyright (C)  2012 University of Bonn. All rights reserved.
+ * 
+ *
+ *   This file is part of MoleCuilder.
+ *
+ *    MoleCuilder 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 2 of the License, or
+ *    (at your option) any later version.
+ *
+ *    MoleCuilder 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 MoleCuilder.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * SamplingGridUnitTest.cpp
+ *
+ *  Created on: Jul 29, 2012
+ *      Author: heber
+ */
+
+// include config.h
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+using namespace std;
+
+#include <cppunit/CompilerOutputter.h>
+#include <cppunit/extensions/TestFactoryRegistry.h>
+#include <cppunit/ui/text/TestRunner.h>
+
+#include "SamplingGridUnitTest.hpp"
+
+#include "CodePatterns/Assert.hpp"
+
+#include <cmath>
+#include <boost/assign.hpp>
+
+#ifdef HAVE_TESTRUNNER
+#include "UnitTestMain.hpp"
+#endif /*HAVE_TESTRUNNER*/
+
+using namespace boost::assign;
+
+/********************************************** Test classes **************************************/
+
+const double grid_value=1.;
+
+// Registers the fixture into the 'registry'
+CPPUNIT_TEST_SUITE_REGISTRATION( SamplingGridTest );
+
+
+void SamplingGridTest::setUp()
+{
+  // failing asserts should be thrown
+  ASSERT_DO(Assert::Throw);
+
+  // create the grid
+  const double begin[3] = { 0., 0., 0. };
+  for (size_t i=0; i< pow(pow(2,2),3); ++i)
+    values += grid_value;
+  grid = new SamplingGrid(begin, 1., 2, values);
+  CPPUNIT_ASSERT_EQUAL( grid_value, *(grid->sampled_grid.begin()) );
+}
+
+
+void SamplingGridTest::tearDown()
+{
+  delete grid;
+}
+
+#define NUMBEROFSAMPLES(n) pow(pow(2,n),3)
+
+/** UnitTest for operator+=()
+ */
+void SamplingGridTest::superposeOtherGrid_Test()
+{
+  // check illegal grid
+  const double begin[3] = { 0., 0., 0. };
+  SamplingGridProperties illegal_props(begin, 2., 1);
+  CPPUNIT_ASSERT( !grid->isCompatible(illegal_props) );
+  SamplingGrid::sampledvalues_t illegal_values;
+  for (size_t i=0; i< NUMBEROFSAMPLES(1); ++i)
+    illegal_values += 1.5;
+  SamplingGrid illegal_grid(illegal_props, illegal_values);
+#ifndef NDEBUG
+  CPPUNIT_ASSERT_THROW( *grid += illegal_grid, Assert::AssertionFailure );
+#else
+  *grid += illegal_grid;
+#endif
+
+  // check that grid is still the same
+  for (SamplingGrid::sampledvalues_t::const_iterator iter = grid->sampled_grid.begin();
+      iter != grid->sampled_grid.end(); ++iter)
+    CPPUNIT_ASSERT_EQUAL( grid_value, *iter );
+}
+
+/** UnitTest for operator+=()
+ */
+void SamplingGridTest::operatorPlusEqual_Test()
+{
+  // create other grid
+  const double begin[3] = { 0., 0., 0. };
+  SamplingGrid::sampledvalues_t othervalues;
+  const double othergrid_value = 1.5;
+  for (size_t i=0; i< NUMBEROFSAMPLES(2); ++i)
+    othervalues += othergrid_value;
+  SamplingGrid othergrid(begin, 1., 2, othervalues);
+  CPPUNIT_ASSERT_EQUAL( othergrid_value, *(othergrid.sampled_grid.begin()) );
+
+  // perform operation
+  CPPUNIT_ASSERT_NO_THROW( *grid += othergrid );
+
+  // check the contents of the grid
+  const double sum = grid_value+othergrid_value;
+  for (SamplingGrid::sampledvalues_t::const_iterator iter = grid->sampled_grid.begin();
+      iter != grid->sampled_grid.end(); ++iter)
+    CPPUNIT_ASSERT_EQUAL( sum, *iter );
+}
+
+/** UnitTest for operator-=()
+ */
+void SamplingGridTest::operatorMinusEqual_Test()
+{
+  // create other grid
+  const double begin[3] = { 0., 0., 0. };
+  SamplingGrid::sampledvalues_t othervalues;
+  const double othergrid_value = 1.5;
+  for (size_t i=0; i< NUMBEROFSAMPLES(2); ++i)
+    othervalues += othergrid_value;
+  SamplingGrid othergrid(begin, 1., 2, othervalues);
+  CPPUNIT_ASSERT_EQUAL( othergrid_value, *(othergrid.sampled_grid.begin()) );
+
+  // perform operation
+  CPPUNIT_ASSERT_NO_THROW( *grid -= othergrid );
+
+  // check the contents of the grid
+  const double difference = grid_value-othergrid_value;
+  for (SamplingGrid::sampledvalues_t::const_iterator iter = grid->sampled_grid.begin();
+      iter != grid->sampled_grid.end(); ++iter)
+    CPPUNIT_ASSERT_EQUAL( difference, *iter );
+}
+
