Squashed 'third_party/eigen/' content from commit 61d72f6

Change-Id: Iccc90fa0b55ab44037f018046d2fcffd90d9d025
git-subtree-dir: third_party/eigen
git-subtree-split: 61d72f6383cfa842868c53e30e087b0258177257
diff --git a/test/eigen2/eigen2_lu.cpp b/test/eigen2/eigen2_lu.cpp
new file mode 100644
index 0000000..e993b1c
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+++ b/test/eigen2/eigen2_lu.cpp
@@ -0,0 +1,122 @@
+// 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 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include "main.h"
+#include <Eigen/LU>
+
+template<typename Derived>
+void doSomeRankPreservingOperations(Eigen::MatrixBase<Derived>& m)
+{
+  typedef typename Derived::RealScalar RealScalar;
+  for(int a = 0; a < 3*(m.rows()+m.cols()); a++)
+  {
+    RealScalar d = Eigen::ei_random<RealScalar>(-1,1);
+    int i = Eigen::ei_random<int>(0,m.rows()-1); // i is a random row number
+    int j;
+    do {
+      j = Eigen::ei_random<int>(0,m.rows()-1);
+    } while (i==j); // j is another one (must be different)
+    m.row(i) += d * m.row(j);
+
+    i = Eigen::ei_random<int>(0,m.cols()-1); // i is a random column number
+    do {
+      j = Eigen::ei_random<int>(0,m.cols()-1);
+    } while (i==j); // j is another one (must be different)
+    m.col(i) += d * m.col(j);
+  }
+}
+
+template<typename MatrixType> void lu_non_invertible()
+{
+  /* this test covers the following files:
+     LU.h
+  */
+  // NOTE there seems to be a problem with too small sizes -- could easily lie in the doSomeRankPreservingOperations function
+  int rows = ei_random<int>(20,200), cols = ei_random<int>(20,200), cols2 = ei_random<int>(20,200);
+  int rank = ei_random<int>(1, std::min(rows, cols)-1);
+
+  MatrixType m1(rows, cols), m2(cols, cols2), m3(rows, cols2), k(1,1);
+  m1 = MatrixType::Random(rows,cols);
+  if(rows <= cols)
+    for(int i = rank; i < rows; i++) m1.row(i).setZero();
+  else
+    for(int i = rank; i < cols; i++) m1.col(i).setZero();
+  doSomeRankPreservingOperations(m1);
+
+  LU<MatrixType> lu(m1);
+  typename LU<MatrixType>::KernelResultType m1kernel = lu.kernel();
+  typename LU<MatrixType>::ImageResultType m1image = lu.image();
+
+  VERIFY(rank == lu.rank());
+  VERIFY(cols - lu.rank() == lu.dimensionOfKernel());
+  VERIFY(!lu.isInjective());
+  VERIFY(!lu.isInvertible());
+  VERIFY(lu.isSurjective() == (lu.rank() == rows));
+  VERIFY((m1 * m1kernel).isMuchSmallerThan(m1));
+  VERIFY(m1image.lu().rank() == rank);
+  MatrixType sidebyside(m1.rows(), m1.cols() + m1image.cols());
+  sidebyside << m1, m1image;
+  VERIFY(sidebyside.lu().rank() == rank);
+  m2 = MatrixType::Random(cols,cols2);
+  m3 = m1*m2;
+  m2 = MatrixType::Random(cols,cols2);
+  lu.solve(m3, &m2);
+  VERIFY_IS_APPROX(m3, m1*m2);
+  /* solve now always returns true
+  m3 = MatrixType::Random(rows,cols2);
+  VERIFY(!lu.solve(m3, &m2));
+  */
+}
+
+template<typename MatrixType> void lu_invertible()
+{
+  /* this test covers the following files:
+     LU.h
+  */
+  typedef typename NumTraits<typename MatrixType::Scalar>::Real RealScalar;
+  int size = ei_random<int>(10,200);
+
+  MatrixType m1(size, size), m2(size, size), m3(size, size);
+  m1 = MatrixType::Random(size,size);
+
+  if (ei_is_same_type<RealScalar,float>::ret)
+  {
+    // let's build a matrix more stable to inverse
+    MatrixType a = MatrixType::Random(size,size*2);
+    m1 += a * a.adjoint();
+  }
+
+  LU<MatrixType> lu(m1);
+  VERIFY(0 == lu.dimensionOfKernel());
+  VERIFY(size == lu.rank());
+  VERIFY(lu.isInjective());
+  VERIFY(lu.isSurjective());
+  VERIFY(lu.isInvertible());
+  VERIFY(lu.image().lu().isInvertible());
+  m3 = MatrixType::Random(size,size);
+  lu.solve(m3, &m2);
+  VERIFY_IS_APPROX(m3, m1*m2);
+  VERIFY_IS_APPROX(m2, lu.inverse()*m3);
+  m3 = MatrixType::Random(size,size);
+  VERIFY(lu.solve(m3, &m2));
+}
+
+void test_eigen2_lu()
+{
+  for(int i = 0; i < g_repeat; i++) {
+    CALL_SUBTEST_1( lu_non_invertible<MatrixXf>() );
+    CALL_SUBTEST_2( lu_non_invertible<MatrixXd>() );
+    CALL_SUBTEST_3( lu_non_invertible<MatrixXcf>() );
+    CALL_SUBTEST_4( lu_non_invertible<MatrixXcd>() );
+    CALL_SUBTEST_1( lu_invertible<MatrixXf>() );
+    CALL_SUBTEST_2( lu_invertible<MatrixXd>() );
+    CALL_SUBTEST_3( lu_invertible<MatrixXcf>() );
+    CALL_SUBTEST_4( lu_invertible<MatrixXcd>() );
+  }
+}