Refactor matrix_function test in preparation of next commit.

unsupported/test/matrix_function.cpp

@@ -25,28 +25,19 @@
 #include "main.h"
 #include <unsupported/Eigen/MatrixFunctions>
 
-// Returns either a matrix with iid random entries or a matrix with
+// Returns a matrix with eigenvalues clustered around 0, 1 and 2.
-// clustered eigenvalues. Matrices with clustered eigenvalue clusters
-// lead to different code paths in MatrixFunction.h and are thus
-// useful for testing.
 template<typename MatrixType>
-MatrixType createRandomMatrix(const int size)
+MatrixType randomMatrixWithRealEivals(const int size)
 {
   typedef typename MatrixType::Scalar Scalar;
   typedef typename MatrixType::RealScalar RealScalar;
-  MatrixType result;
-  if (ei_random<int>(0,1) == 0) {
-    result = MatrixType::Random(size, size);
-  } else {
   MatrixType diag = MatrixType::Zero(size, size);
   for (int i = 0; i < size; ++i) {
     diag(i, i) = Scalar(RealScalar(ei_random<int>(0,2)))
       + ei_random<Scalar>() * Scalar(RealScalar(0.01));
   }
   MatrixType A = MatrixType::Random(size, size);
-    result = A.inverse() * diag * A;
+  return A.inverse() * diag * A;
-  }
-  return result;
 }
 
 template<typename MatrixType>
@@ -109,14 +100,24 @@ void testGonioFunctions(const MatrixType& A)
 }
 
 template<typename MatrixType>
-void testMatrixType(const MatrixType& m)
+void testMatrix(const MatrixType& A)
 {
-  for (int i = 0; i < g_repeat; i++) {
-    MatrixType A = createRandomMatrix<MatrixType>(m.rows());
   testMatrixExponential(A);
   testHyperbolicFunctions(A);
   testGonioFunctions(A);
 }
+
+template<typename MatrixType>
+void testMatrixType(const MatrixType& m)
+{
+  // Matrices with clustered eigenvalue lead to different code paths
+  // in MatrixFunction.h and are thus useful for testing.
+
+  const int size = m.rows();
+  for (int i = 0; i < g_repeat; i++) {
+    testMatrix(MatrixType::Random(size, size).eval());
+    testMatrix(randomMatrixWithRealEivals<MatrixType>(size));
+  }
 }
 
 void test_matrix_function()