From 638afe235fcf0535750c270890f4b8aad54a32fc Mon Sep 17 00:00:00 2001
From: Rene Gassmoeller <rene.gassmoeller@mailbox.org>
Date: Mon, 4 Nov 2024 11:03:25 +0100
Subject: [PATCH] Add test

---
 tests/tensors/tensor_33.cc     | 67 ++++++++++++++++++++++++++++++++++
 tests/tensors/tensor_33.output | 20 ++++++++++
 2 files changed, 87 insertions(+)
 create mode 100644 tests/tensors/tensor_33.cc
 create mode 100644 tests/tensors/tensor_33.output

diff --git a/tests/tensors/tensor_33.cc b/tests/tensors/tensor_33.cc
new file mode 100644
index 0000000000..7f3d2c6d46
--- /dev/null
+++ b/tests/tensors/tensor_33.cc
@@ -0,0 +1,67 @@
+// ------------------------------------------------------------------------
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+// Copyright (C) 2017 - 2020 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// Part of the source code is dual licensed under Apache-2.0 WITH
+// LLVM-exception OR LGPL-2.1-or-later. Detailed license information
+// governing the source code and code contributions can be found in
+// LICENSE.md and CONTRIBUTING.md at the top level directory of deal.II.
+//
+// ------------------------------------------------------------------------
+
+
+// Test that we can convert a Tensor of a given rank and dimension to a Tensor
+// of Tensors of rank-1 and dimension dim.
+
+#include <deal.II/base/table_indices.h>
+#include <deal.II/base/tensor.h>
+#include <deal.II/base/utilities.h>
+
+#include "../tests.h"
+
+
+template <int rank, int dim>
+void
+test()
+{
+  std::vector<double> values(Utilities::fixed_power<rank>(dim), 0.0);
+  std::iota(values.begin(), values.end(), 0.0);
+
+  Tensor<rank, dim>  t(make_array_view(values));
+  TableIndices<rank> indices;
+
+  Tensor<1, dim, Tensor<rank - 1, dim>> t2(t);
+
+  // Check for Tensor<rank,dim>
+  deallog << "Rank: " << std::to_string(rank)
+          << ". Dim: " << std::to_string(dim) << ". Tensor1: " << t
+          << std::endl;
+
+  // Check for Tensor<1,dim,Tensor<rank-1,dim>>
+  deallog << "Rank: " << std::to_string(rank)
+          << ". Dim: " << std::to_string(dim) << ". Tensor2: " << t2
+          << std::endl;
+}
+
+int
+main(int argc, char *argv[])
+{
+  initlog();
+
+  test<1, 1>();
+  test<2, 1>();
+  test<3, 1>();
+  test<1, 2>();
+  test<2, 2>();
+  test<3, 2>();
+  test<1, 3>();
+  test<2, 3>();
+  test<3, 3>();
+
+  deallog << "OK" << std::endl;
+
+  return 0;
+}
diff --git a/tests/tensors/tensor_33.output b/tests/tensors/tensor_33.output
new file mode 100644
index 0000000000..8bb86ac0e2
--- /dev/null
+++ b/tests/tensors/tensor_33.output
@@ -0,0 +1,20 @@
+
+DEAL::Rank: 1. Dim: 1. Tensor1: 0.00000
+DEAL::Rank: 1. Dim: 1. Tensor2: 0.00000
+DEAL::Rank: 2. Dim: 1. Tensor1: 0.00000
+DEAL::Rank: 2. Dim: 1. Tensor2: 0.00000
+DEAL::Rank: 3. Dim: 1. Tensor1: 0.00000
+DEAL::Rank: 3. Dim: 1. Tensor2: 0.00000
+DEAL::Rank: 1. Dim: 2. Tensor1: 0.00000 1.00000
+DEAL::Rank: 1. Dim: 2. Tensor2: 0.00000 1.00000
+DEAL::Rank: 2. Dim: 2. Tensor1: 0.00000 1.00000  2.00000 3.00000
+DEAL::Rank: 2. Dim: 2. Tensor2: 0.00000 1.00000 2.00000 3.00000
+DEAL::Rank: 3. Dim: 2. Tensor1: 0.00000 1.00000  2.00000 3.00000   4.00000 5.00000  6.00000 7.00000
+DEAL::Rank: 3. Dim: 2. Tensor2: 0.00000 1.00000  2.00000 3.00000 4.00000 5.00000  6.00000 7.00000
+DEAL::Rank: 1. Dim: 3. Tensor1: 0.00000 1.00000 2.00000
+DEAL::Rank: 1. Dim: 3. Tensor2: 0.00000 1.00000 2.00000
+DEAL::Rank: 2. Dim: 3. Tensor1: 0.00000 1.00000 2.00000  3.00000 4.00000 5.00000  6.00000 7.00000 8.00000
+DEAL::Rank: 2. Dim: 3. Tensor2: 0.00000 1.00000 2.00000 3.00000 4.00000 5.00000 6.00000 7.00000 8.00000
+DEAL::Rank: 3. Dim: 3. Tensor1: 0.00000 1.00000 2.00000  3.00000 4.00000 5.00000  6.00000 7.00000 8.00000   9.00000 10.0000 11.0000  12.0000 13.0000 14.0000  15.0000 16.0000 17.0000   18.0000 19.0000 20.0000  21.0000 22.0000 23.0000  24.0000 25.0000 26.0000
+DEAL::Rank: 3. Dim: 3. Tensor2: 0.00000 1.00000 2.00000  3.00000 4.00000 5.00000  6.00000 7.00000 8.00000 9.00000 10.0000 11.0000  12.0000 13.0000 14.0000  15.0000 16.0000 17.0000 18.0000 19.0000 20.0000  21.0000 22.0000 23.0000  24.0000 25.0000 26.0000
+DEAL::OK
-- 
2.39.5