added a unit test for Inverse

discovered that m1 == m1.inverse().inverse() fails though
m1.inverse()*m1 == I

1 files changed, 69 insertions, 0 deletions

diff --git a/test/inverse.cpp b/test/inverse.cpp
new file mode 100644
index 000000000..ac5d7f180
--- /dev/null
+++ b/test/inverse.cpp
@@ -0,0 +1,69 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2008 Gael Guennebaud <g.gael@free.fr>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, 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.
+//
+// Eigen 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 Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#include "main.h"
+#include <Eigen/LU>
+
+template<typename MatrixType> void inverse(const MatrixType& m)
+{
+  /* this test covers the following files:
+     Inverse.h
+  */
+  int rows = m.rows();
+  int cols = m.cols();
+
+  typedef typename MatrixType::Scalar Scalar;
+  typedef Matrix<Scalar, MatrixType::ColsAtCompileTime, 1> VectorType;
+
+  MatrixType m1 = MatrixType::random(rows, cols),
+             m2 = MatrixType::random(rows, cols),
+             m3(rows, cols),
+             mzero = MatrixType::zero(rows, cols),
+             identity = MatrixType::identity(rows, rows);
+
+  m2 = m1.inverse();
+  VERIFY_IS_APPROX(m1, m2.inverse() );
+
+  m3 = (m1+m2).inverse();
+  VERIFY_IS_APPROX(m3+m1, (m1+m2).inverse()+m1);
+
+  VERIFY_IS_APPROX(m1, m1.inverse().eval().inverse() );
+
+  VERIFY_IS_NOT_APPROX(m1, m1.inverse() );
+  VERIFY_IS_APPROX(identity, m1.inverse() * m1 );
+  VERIFY_IS_APPROX(identity, m1 * m1.inverse() );
+
+  // this one fails:
+  VERIFY_IS_APPROX(m1, (m1.inverse()).inverse() );
+}
+
+void test_inverse()
+{
+  for(int i = 0; i < 1; i++) {
+    CALL_SUBTEST( inverse(Matrix2f()) );
+    CALL_SUBTEST( inverse(Matrix3f()) );
+    CALL_SUBTEST( inverse(Matrix4d()) );
+//     CALL_SUBTEST( inverse(MatrixXcd(7,7)) );
+  }
+}