From 52e8c78dc4ba049b757aff2347a296d2bd330bf9 Mon Sep 17 00:00:00 2001
From: Daniel Garcia-Sanchez <daniel.garcia-sanchez@insp.upmc.fr>
Date: Wed, 9 Oct 2019 12:42:12 +0200
Subject: [PATCH] Add test integrate_difference_01_complex_04

---
 .../integrate_difference_01_complex_04.cc     | 116 ++++++++++++++++++
 ...1_complex_04.with_complex_values=on.output |   4 +
 2 files changed, 120 insertions(+)
 create mode 100644 tests/vector_tools/integrate_difference_01_complex_04.cc
 create mode 100644 tests/vector_tools/integrate_difference_01_complex_04.with_complex_values=on.output

diff --git a/tests/vector_tools/integrate_difference_01_complex_04.cc b/tests/vector_tools/integrate_difference_01_complex_04.cc
new file mode 100644
index 0000000000..bb750b3f10
--- /dev/null
+++ b/tests/vector_tools/integrate_difference_01_complex_04.cc
@@ -0,0 +1,116 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2003 - 2018 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, 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 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE.md at
+// the top level directory of deal.II.
+//
+// ---------------------------------------------------------------------
+
+
+// Test integrate_difference for complex-valued vectors. This test is
+// like integrate_difference_01_complex_04, but compares the interpolated
+// solution to the exact solution.
+
+#include <deal.II/base/function.h>
+#include <deal.II/base/quadrature_lib.h>
+#include <deal.II/base/signaling_nan.h>
+
+#include <deal.II/dofs/dof_tools.h>
+
+#include <deal.II/fe/fe_q.h>
+#include <deal.II/fe/fe_system.h>
+
+#include <deal.II/grid/grid_generator.h>
+#include <deal.II/grid/grid_refinement.h>
+#include <deal.II/grid/tria.h>
+#include <deal.II/grid/tria_accessor.h>
+
+#include <deal.II/lac/vector.h>
+
+#include <deal.II/numerics/vector_tools.h>
+
+#include "../tests.h"
+
+using namespace dealii;
+
+
+// x+y(+z), x^2+y^2 (, z+xy) times (1+i)/sqrt(2)
+template <int dim>
+class Ref : public Function<dim, std::complex<double>>
+{
+public:
+  Ref()
+    : Function<dim, std::complex<double>>(dim)
+  {}
+
+  std::complex<double>
+  value(const Point<dim> &p, const unsigned int c) const
+  {
+    if (c == 0)
+      return (p[0] + p[1] + ((dim == 3) ? p[2] : 0.0)) *
+             std::complex<double>(1. / std::sqrt(2.), 1. / std::sqrt(2.));
+    if (c == 1)
+      return (p[0] * p[0] + p[1] * p[1]) *
+             std::complex<double>(1. / std::sqrt(2.), 1. / std::sqrt(2.));
+    if (c == 2)
+      return (p[2] + p[0] * p[1]) *
+             std::complex<double>(1. / std::sqrt(2.), 1. / std::sqrt(2.));
+    else
+      return numbers::signaling_nan<double>();
+  }
+};
+
+
+
+template <int dim>
+void
+test(VectorTools::NormType norm, double value)
+{
+  Triangulation<dim> tria;
+  GridGenerator::hyper_cube(tria);
+  tria.refine_global(1);
+
+  FESystem<dim>   fe(FE_Q<dim>(4), dim);
+  DoFHandler<dim> dofh(tria);
+  dofh.distribute_dofs(fe);
+
+  Vector<std::complex<double>> solution(dofh.n_dofs());
+  VectorTools::interpolate(dofh, Ref<dim>(), solution);
+
+  Vector<double> cellwise_errors(tria.n_active_cells());
+  VectorTools::integrate_difference(
+    dofh, solution, Ref<dim>(), cellwise_errors, QGauss<dim>(5), norm);
+
+  const double error = cellwise_errors.l2_norm();
+
+  const double difference = std::abs(error - value);
+  deallog << "computed: " << error << " expected: " << value
+          << " difference: " << difference << std::endl;
+  Assert(difference < 1e-10, ExcMessage("Error in integrate_difference"));
+}
+
+template <int dim>
+void
+test()
+{
+  deallog << "L2_norm:" << std::endl;
+  // sqrt(\int_\Omega f^2) = sqrt(\int (x+y)^2+(x^2+y^2)^2)
+  test<dim>(VectorTools::L2_norm, 0.);
+
+  deallog << "OK" << std::endl;
+}
+
+
+int
+main(int argc, char **argv)
+{
+  initlog();
+  test<2>();
+}
diff --git a/tests/vector_tools/integrate_difference_01_complex_04.with_complex_values=on.output b/tests/vector_tools/integrate_difference_01_complex_04.with_complex_values=on.output
new file mode 100644
index 0000000000..496092bb8e
--- /dev/null
+++ b/tests/vector_tools/integrate_difference_01_complex_04.with_complex_values=on.output
@@ -0,0 +1,4 @@
+
+DEAL::L2_norm:
+DEAL::computed: 2.68836e-16 expected: 0.00000 difference: 2.68836e-16
+DEAL::OK
-- 
2.39.5