4x4 inverse:

* change block selection threshold from 1e-2 to 1e-1
* add rigorous precision test

4 files changed, 95 insertions, 12 deletions

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 30668a2aa..c91ec328b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -160,6 +160,8 @@ ei_add_test(swap)
 ei_add_test(conservative_resize)
 ei_add_test(permutationmatrices)
 
+ei_add_test(prec_inverse_4x4)
+
 ei_add_property(EIGEN_TESTING_SUMMARY "CXX:               ${CMAKE_CXX_COMPILER}\n")
 if(CMAKE_COMPILER_IS_GNUCXX)
   execute_process(COMMAND ${CMAKE_CXX_COMPILER} --version COMMAND head -n 1 OUTPUT_VARIABLE EIGEN_CXX_VERSION_STRING OUTPUT_STRIP_TRAILING_WHITESPACE)
diff --git a/test/inverse.cpp b/test/inverse.cpp
index 3ed61d356..59b791507 100644
--- a/test/inverse.cpp
+++ b/test/inverse.cpp
@@ -104,12 +104,4 @@ void test_inverse()
     s = ei_random<int>(25,100);
     CALL_SUBTEST_6( inverse(MatrixXcd(s,s)) );
   }
-
-#ifdef EIGEN_TEST_PART_4
-  // test some tricky cases for 4x4 matrices
-  VERIFY_IS_APPROX((Matrix4f() << 0,0,1,0, 1,0,0,0, 0,1,0,0, 0,0,0,1).finished().inverse(),
-                   (Matrix4f() << 0,1,0,0, 0,0,1,0, 1,0,0,0, 0,0,0,1).finished());
-  VERIFY_IS_APPROX((Matrix4f() << 1,0,0,0, 0,0,1,0, 0,0,0,1, 0,1,0,0).finished().inverse(),
-                   (Matrix4f() << 1,0,0,0, 0,0,0,1, 0,1,0,0, 0,0,1,0).finished());
-#endif
 }
diff --git a/test/main.h b/test/main.h
index 0b9b0bc4c..3ae573c1e 100644
--- a/test/main.h
+++ b/test/main.h
@@ -372,6 +372,14 @@ template<> struct GetDifferentType<double> { typedef float type; };
 template<typename T> struct GetDifferentType<std::complex<T> >
 { typedef std::complex<typename GetDifferentType<T>::type> type; };
 
+template<typename T> std::string type_name() { return "other"; }
+template<> std::string type_name<float>() { return "float"; }
+template<> std::string type_name<double>() { return "double"; }
+template<> std::string type_name<int>() { return "int"; }
+template<> std::string type_name<std::complex<float> >() { return "complex<float>"; }
+template<> std::string type_name<std::complex<double> >() { return "complex<double>"; }
+template<> std::string type_name<std::complex<int> >() { return "complex<int>"; }
+
 // forward declaration of the main test function
 void EIGEN_CAT(test_,EIGEN_TEST_FUNC)();
 
@@ -444,7 +452,4 @@ int main(int argc, char *argv[])
 
     EIGEN_CAT(test_,EIGEN_TEST_FUNC)();
     return 0;
-}
-
-
-
+}
\ No newline at end of file
diff --git a/test/prec_inverse_4x4.cpp b/test/prec_inverse_4x4.cpp
new file mode 100644
index 000000000..77763f830
--- /dev/null
+++ b/test/prec_inverse_4x4.cpp
@@ -0,0 +1,84 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// 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>
+#include <algorithm>
+
+template<typename MatrixType> void inverse_permutation_4x4()
+{
+  typedef typename MatrixType::Scalar Scalar;
+  typedef typename MatrixType::RealScalar RealScalar;
+  double error_max = 0.;
+  Vector4i indices(0,1,2,3);
+  for(int i = 0; i < 24; ++i)
+  {
+    MatrixType m = PermutationMatrix<4>(indices);
+    MatrixType inv = m.inverse();
+    double error = double( (m*inv-MatrixType::Identity()).norm() / epsilon<Scalar>() );
+    error_max = std::max(error_max, error);
+    std::next_permutation(indices.data(),indices.data()+4);
+  }
+  std::cerr << "inverse_permutation_4x4, Scalar = " << type_name<Scalar>() << std::endl;
+  EIGEN_DEBUG_VAR(error_max);
+  VERIFY(error_max < (NumTraits<Scalar>::IsComplex ? 150.0 : 60.) );
+}
+
+template<typename MatrixType> void inverse_general_4x4(int repeat)
+{
+  typedef typename MatrixType::Scalar Scalar;
+  typedef typename MatrixType::RealScalar RealScalar;
+  double error_sum = 0., error_max = 0.;
+  for(int i = 0; i < repeat; ++i)
+  {
+    MatrixType m;
+    RealScalar absdet;
+    do {
+      m = MatrixType::Random();
+      absdet = ei_abs(m.determinant());
+    } while(absdet == RealScalar(0));
+    MatrixType inv = m.inverse();
+    double error = double( (m*inv-MatrixType::Identity()).norm() * absdet / epsilon<Scalar>() );
+    error_sum += error;
+    error_max = std::max(error_max, error);
+  }
+  std::cerr << "inverse_general_4x4, Scalar = " << type_name<Scalar>() << std::endl;
+  double error_avg = error_sum / repeat;
+  EIGEN_DEBUG_VAR(error_avg);
+  EIGEN_DEBUG_VAR(error_max);
+  VERIFY(error_avg < (NumTraits<Scalar>::IsComplex ? 8.4 : 1.4) );
+  VERIFY(error_max < (NumTraits<Scalar>::IsComplex ? 150.0 : 60.) );
+}
+
+void test_prec_inverse_4x4()
+{
+  CALL_SUBTEST_1((inverse_permutation_4x4<Matrix4f>()));
+  CALL_SUBTEST_1(( inverse_general_4x4<Matrix4f>(200000 * g_repeat) ));
+
+  CALL_SUBTEST_2((inverse_permutation_4x4<Matrix<double,4,4,RowMajor> >()));
+  CALL_SUBTEST_2(( inverse_general_4x4<Matrix<double,4,4,RowMajor> >(200000 * g_repeat) ));
+
+  CALL_SUBTEST_3((inverse_permutation_4x4<Matrix4cf>()));
+  CALL_SUBTEST_3((inverse_general_4x4<Matrix4cf>(50000 * g_repeat)));
+}