diff --git a/test/diagonalmatrices.cpp b/test/diagonalmatrices.cpp
new file mode 100644
index 0000000..149f1db
--- /dev/null
+++ b/test/diagonalmatrices.cpp
@@ -0,0 +1,102 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2009 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"
+using namespace std;
+template<typename MatrixType> void diagonalmatrices(const MatrixType& m)
+{
+  typedef typename MatrixType::Index Index;
+  typedef typename MatrixType::Scalar Scalar;
+  enum { Rows = MatrixType::RowsAtCompileTime, Cols = MatrixType::ColsAtCompileTime };
+  typedef Matrix<Scalar, Rows, 1> VectorType;
+  typedef Matrix<Scalar, 1, Cols> RowVectorType;
+  typedef Matrix<Scalar, Rows, Rows> SquareMatrixType;
+  typedef DiagonalMatrix<Scalar, Rows> LeftDiagonalMatrix;
+  typedef DiagonalMatrix<Scalar, Cols> RightDiagonalMatrix;
+  typedef Matrix<Scalar, Rows==Dynamic?Dynamic:2*Rows, Cols==Dynamic?Dynamic:2*Cols> BigMatrix;
+  Index rows = m.rows();
+  Index cols = m.cols();
+
+  MatrixType m1 = MatrixType::Random(rows, cols),
+             m2 = MatrixType::Random(rows, cols);
+  VectorType v1 = VectorType::Random(rows),
+             v2 = VectorType::Random(rows);
+  RowVectorType rv1 = RowVectorType::Random(cols),
+             rv2 = RowVectorType::Random(cols);
+  LeftDiagonalMatrix ldm1(v1), ldm2(v2);
+  RightDiagonalMatrix rdm1(rv1), rdm2(rv2);
+  
+  Scalar s1 = internal::random<Scalar>();
+
+  SquareMatrixType sq_m1 (v1.asDiagonal());
+  VERIFY_IS_APPROX(sq_m1, v1.asDiagonal().toDenseMatrix());
+  sq_m1 = v1.asDiagonal();
+  VERIFY_IS_APPROX(sq_m1, v1.asDiagonal().toDenseMatrix());
+  SquareMatrixType sq_m2 = v1.asDiagonal();
+  VERIFY_IS_APPROX(sq_m1, sq_m2);
+  
+  ldm1 = v1.asDiagonal();
+  LeftDiagonalMatrix ldm3(v1);
+  VERIFY_IS_APPROX(ldm1.diagonal(), ldm3.diagonal());
+  LeftDiagonalMatrix ldm4 = v1.asDiagonal();
+  VERIFY_IS_APPROX(ldm1.diagonal(), ldm4.diagonal());
+  
+  sq_m1.block(0,0,rows,rows) = ldm1;
+  VERIFY_IS_APPROX(sq_m1, ldm1.toDenseMatrix());
+  sq_m1.transpose() = ldm1;
+  VERIFY_IS_APPROX(sq_m1, ldm1.toDenseMatrix());
+  
+  Index i = internal::random<Index>(0, rows-1);
+  Index j = internal::random<Index>(0, cols-1);
+  
+  VERIFY_IS_APPROX( ((ldm1 * m1)(i,j))  , ldm1.diagonal()(i) * m1(i,j) );
+  VERIFY_IS_APPROX( ((ldm1 * (m1+m2))(i,j))  , ldm1.diagonal()(i) * (m1+m2)(i,j) );
+  VERIFY_IS_APPROX( ((m1 * rdm1)(i,j))  , rdm1.diagonal()(j) * m1(i,j) );
+  VERIFY_IS_APPROX( ((v1.asDiagonal() * m1)(i,j))  , v1(i) * m1(i,j) );
+  VERIFY_IS_APPROX( ((m1 * rv1.asDiagonal())(i,j))  , rv1(j) * m1(i,j) );
+  VERIFY_IS_APPROX( (((v1+v2).asDiagonal() * m1)(i,j))  , (v1+v2)(i) * m1(i,j) );
+  VERIFY_IS_APPROX( (((v1+v2).asDiagonal() * (m1+m2))(i,j))  , (v1+v2)(i) * (m1+m2)(i,j) );
+  VERIFY_IS_APPROX( ((m1 * (rv1+rv2).asDiagonal())(i,j))  , (rv1+rv2)(j) * m1(i,j) );
+  VERIFY_IS_APPROX( (((m1+m2) * (rv1+rv2).asDiagonal())(i,j))  , (rv1+rv2)(j) * (m1+m2)(i,j) );
+
+  BigMatrix big;
+  big.setZero(2*rows, 2*cols);
+  
+  big.block(i,j,rows,cols) = m1;
+  big.block(i,j,rows,cols) = v1.asDiagonal() * big.block(i,j,rows,cols);
+  
+  VERIFY_IS_APPROX((big.block(i,j,rows,cols)) , v1.asDiagonal() * m1 );
+  
+  big.block(i,j,rows,cols) = m1;
+  big.block(i,j,rows,cols) = big.block(i,j,rows,cols) * rv1.asDiagonal();
+  VERIFY_IS_APPROX((big.block(i,j,rows,cols)) , m1 * rv1.asDiagonal() );
+  
+  
+  // scalar multiple
+  VERIFY_IS_APPROX(LeftDiagonalMatrix(ldm1*s1).diagonal(), ldm1.diagonal() * s1);
+  VERIFY_IS_APPROX(LeftDiagonalMatrix(s1*ldm1).diagonal(), s1 * ldm1.diagonal());
+  
+  VERIFY_IS_APPROX(m1 * (rdm1 * s1), (m1 * rdm1) * s1);
+  VERIFY_IS_APPROX(m1 * (s1 * rdm1), (m1 * rdm1) * s1);
+}
+
+void test_diagonalmatrices()
+{
+  for(int i = 0; i < g_repeat; i++) {
+    CALL_SUBTEST_1( diagonalmatrices(Matrix<float, 1, 1>()) );
+    CALL_SUBTEST_2( diagonalmatrices(Matrix3f()) );
+    CALL_SUBTEST_3( diagonalmatrices(Matrix<double,3,3,RowMajor>()) );
+    CALL_SUBTEST_4( diagonalmatrices(Matrix4d()) );
+    CALL_SUBTEST_5( diagonalmatrices(Matrix<float,4,4,RowMajor>()) );
+    CALL_SUBTEST_6( diagonalmatrices(MatrixXcf(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
+    CALL_SUBTEST_7( diagonalmatrices(MatrixXi(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
+    CALL_SUBTEST_8( diagonalmatrices(Matrix<double,Dynamic,Dynamic,RowMajor>(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
+    CALL_SUBTEST_9( diagonalmatrices(MatrixXf(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
+  }
+}