[T] Added tests for localDOF()

Tests/NumLib/TestLocalDOF.cpp

+/**
+ * \file
+ *
+ * \copyright
+ * Copyright (c) 2012-2023, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ */
+
+#include <gtest/gtest.h>
+
+#include <numeric>
+#include <random>
+
+#include "NumLib/DOF/LocalDOF.h"
+
+static double testLocalDOFRandom()
+{
+    std::random_device device;
+    std::default_random_engine engine(device());
+    std::uniform_real_distribution<double> distribution(100, 200);
+    return distribution(engine);
+}
+
+template <unsigned NPoints>
+struct MockShapeFunction
+{
+    static constexpr unsigned NPOINTS = NPoints;
+};
+
+TEST(NumLib_LocalDOF, Scalar)
+{
+    using N1 = MockShapeFunction<2>;
+    using N2 = MockShapeFunction<3>;
+    using N3 = MockShapeFunction<4>;
+
+    auto const value = testLocalDOFRandom();
+    auto const x = Eigen::VectorXd::LinSpaced(9, value, value + 8).eval();
+
+    auto const [x1, x2, x3] = NumLib::localDOF<N1, N2, N3>(x);
+
+#ifndef OGS_EIGEN_DYNAMIC_SHAPE_MATRICES
+    static_assert(decltype(x1)::RowsAtCompileTime == 2);
+    static_assert(decltype(x2)::RowsAtCompileTime == 3);
+    static_assert(decltype(x3)::RowsAtCompileTime == 4);
+#endif
+
+    ASSERT_EQ(x.rows(), x1.rows() + x2.rows() + x3.rows());
+    ASSERT_EQ(2, x1.rows());
+    ASSERT_EQ(3, x2.rows());
+    ASSERT_EQ(4, x3.rows());
+
+    EXPECT_DOUBLE_EQ(x[0], x1[0]);
+    EXPECT_DOUBLE_EQ(x[1], x1[1]);
+    EXPECT_DOUBLE_EQ(x[2], x2[0]);
+    EXPECT_DOUBLE_EQ(x[3], x2[1]);
+    EXPECT_DOUBLE_EQ(x[4], x2[2]);
+    EXPECT_DOUBLE_EQ(x[5], x3[0]);
+    EXPECT_DOUBLE_EQ(x[6], x3[1]);
+    EXPECT_DOUBLE_EQ(x[7], x3[2]);
+    EXPECT_DOUBLE_EQ(x[8], x3[3]);
+}
+
+TEST(NumLib_LocalDOF, Vectorial)
+{
+    using N1 = MockShapeFunction<2>;
+    using N2 = MockShapeFunction<3>;
+    using N3 = MockShapeFunction<4>;
+
+    constexpr auto num_dof_total = 2 + 3 * 2 + 4;
+
+    // also works with std::vector
+    auto const value = testLocalDOFRandom();
+    std::vector<double> x(num_dof_total);
+    std::iota(x.begin(), x.end(), value);
+
+    {
+        auto const [x1, x2, x3] =
+            NumLib::localDOF<N1, NumLib::Vectorial<N2, 2>, N3>(x);
+
+#ifndef OGS_EIGEN_DYNAMIC_SHAPE_MATRICES
+        static_assert(decltype(x1)::RowsAtCompileTime == 2);
+        static_assert(decltype(x2)::RowsAtCompileTime == 3 * 2);
+        static_assert(decltype(x3)::RowsAtCompileTime == 4);
+#endif
+
+        ASSERT_EQ(num_dof_total, x1.rows() + x2.rows() + x3.rows());
+        ASSERT_EQ(2, x1.rows());
+        ASSERT_EQ(3 * 2, x2.rows());
+        ASSERT_EQ(4, x3.rows());
+
+        EXPECT_DOUBLE_EQ(x[0], x1[0]);
+        EXPECT_DOUBLE_EQ(x[1], x1[1]);
+
+        EXPECT_DOUBLE_EQ(x[2], x2[0]);
+        EXPECT_DOUBLE_EQ(x[3], x2[1]);
+        EXPECT_DOUBLE_EQ(x[4], x2[2]);
+        EXPECT_DOUBLE_EQ(x[5], x2[3]);
+        EXPECT_DOUBLE_EQ(x[6], x2[4]);
+        EXPECT_DOUBLE_EQ(x[7], x2[5]);
+
+        EXPECT_DOUBLE_EQ(x[8], x3[0]);
+        EXPECT_DOUBLE_EQ(x[9], x3[1]);
+        EXPECT_DOUBLE_EQ(x[10], x3[2]);
+        EXPECT_DOUBLE_EQ(x[11], x3[3]);
+    }
+
+    // same but with vectorial d.o.f. first
+    {
+        auto const [x1, x2, x3] =
+            NumLib::localDOF<NumLib::Vectorial<N2, 2>, N1, N3>(x);
+
+#ifndef OGS_EIGEN_DYNAMIC_SHAPE_MATRICES
+        static_assert(decltype(x1)::RowsAtCompileTime == 3 * 2);
+        static_assert(decltype(x2)::RowsAtCompileTime == 2);
+        static_assert(decltype(x3)::RowsAtCompileTime == 4);
+#endif
+
+        ASSERT_EQ(num_dof_total, x1.rows() + x2.rows() + x3.rows());
+        ASSERT_EQ(3 * 2, x1.rows());
+        ASSERT_EQ(2, x2.rows());
+        ASSERT_EQ(4, x3.rows());
+
+        EXPECT_DOUBLE_EQ(x[0], x1[0]);
+        EXPECT_DOUBLE_EQ(x[1], x1[1]);
+        EXPECT_DOUBLE_EQ(x[2], x1[2]);
+        EXPECT_DOUBLE_EQ(x[3], x1[3]);
+        EXPECT_DOUBLE_EQ(x[4], x1[4]);
+        EXPECT_DOUBLE_EQ(x[5], x1[5]);
+
+        EXPECT_DOUBLE_EQ(x[6], x2[0]);
+        EXPECT_DOUBLE_EQ(x[7], x2[1]);
+
+        EXPECT_DOUBLE_EQ(x[8], x3[0]);
+        EXPECT_DOUBLE_EQ(x[9], x3[1]);
+        EXPECT_DOUBLE_EQ(x[10], x3[2]);
+        EXPECT_DOUBLE_EQ(x[11], x3[3]);
+    }
+}