Add unit-test for reshape

- add unittest for dynamic & fixed-size reshape
- fix fixed-size reshape bugs bugs found while testing

1 files changed, 58 insertions, 0 deletions

diff --git a/test/reshape.cpp b/test/reshape.cpp
new file mode 100644
index 000000000..87ffc835b
--- /dev/null
+++ b/test/reshape.cpp
@@ -0,0 +1,58 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2014 yoco <peter.xiau@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 Eigen::Map;
+using Eigen::MatrixXi;
+
+void dynamic_reshape_all_size(int row, int col) {
+  // create matrix(row, col) and filled with 0, 1, 2, ...
+  Eigen::MatrixXi m(row, col);
+  for(int r = 0; r < row; ++r)
+    for(int c = 0; c < col; ++c)
+      m(r, c) = col * c + r;
+
+  // for all possible shape
+  for(int new_r = 1; new_r <= row * col; ++new_r) {
+    // skip invalid shape
+    if(row * col % new_r != 0)
+      continue;
+
+    // reshape and compare
+    int new_c = row * col / new_r;
+    VERIFY_IS_EQUAL(m.reshape(new_r, new_c),
+                    Map<MatrixXi>(m.data(), new_r, new_c));
+  }
+}
+
+// just test a 4x4 matrix, enumerate all combination manually,
+// so I don't have to do template-meta-programming here.
+void static_reshape_all_size() {
+  // create matrix(row, col) and filled with 0, 1, 2, ...
+  int row = 4;
+  int col = 4;
+  Eigen::MatrixXi m(row, col);
+  for(int r = 0; r < row; ++r)
+    for(int c = 0; c < col; ++c)
+      m(r, c) = col * c + r;
+
+  // reshape and compare
+  VERIFY_IS_EQUAL((m.reshape< 1, 16>()), Map<MatrixXi>(m.data(),  1, 16));
+  VERIFY_IS_EQUAL((m.reshape< 2,  8>()), Map<MatrixXi>(m.data(),  2,  8));
+  VERIFY_IS_EQUAL((m.reshape< 4,  4>()), Map<MatrixXi>(m.data(),  4,  4));
+  VERIFY_IS_EQUAL((m.reshape< 8,  2>()), Map<MatrixXi>(m.data(),  8,  2));
+  VERIFY_IS_EQUAL((m.reshape<16,  1>()), Map<MatrixXi>(m.data(), 16,  1));
+}
+
+void test_reshape()
+{
+  CALL_SUBTEST(dynamic_reshape_all_size(4, 4));
+  CALL_SUBTEST(static_reshape_all_size());
+}