array_reverse.cpp revision c981c48f5bc9aefeffc0bcb0cc3934c2fae179dd 
1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
5// Copyright (C) 2009 Ricard Marxer <email@ricardmarxer.com>
6//
7// This Source Code Form is subject to the terms of the Mozilla
8// Public License v. 2.0. If a copy of the MPL was not distributed
9// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
10
11#include "main.h"
12#include <iostream>
13
14using namespace std;
15
16template<typename MatrixType> void reverse(const MatrixType& m)
17{
18  typedef typename MatrixType::Index Index;
19  typedef typename MatrixType::Scalar Scalar;
20  typedef Matrix<Scalar, MatrixType::RowsAtCompileTime, 1> VectorType;
21
22  Index rows = m.rows();
23  Index cols = m.cols();
24
25  // this test relies a lot on Random.h, and there's not much more that we can do
26  // to test it, hence I consider that we will have tested Random.h
27  MatrixType m1 = MatrixType::Random(rows, cols);
28  VectorType v1 = VectorType::Random(rows);
29
30  MatrixType m1_r = m1.reverse();
31  // Verify that MatrixBase::reverse() works
32  for ( int i = 0; i < rows; i++ ) {
33    for ( int j = 0; j < cols; j++ ) {
34      VERIFY_IS_APPROX(m1_r(i, j), m1(rows - 1 - i, cols - 1 - j));
35    }
36  }
37
38  Reverse<MatrixType> m1_rd(m1);
39  // Verify that a Reverse default (in both directions) of an expression works
40  for ( int i = 0; i < rows; i++ ) {
41    for ( int j = 0; j < cols; j++ ) {
42      VERIFY_IS_APPROX(m1_rd(i, j), m1(rows - 1 - i, cols - 1 - j));
43    }
44  }
45
46  Reverse<MatrixType, BothDirections> m1_rb(m1);
47  // Verify that a Reverse in both directions of an expression works
48  for ( int i = 0; i < rows; i++ ) {
49    for ( int j = 0; j < cols; j++ ) {
50      VERIFY_IS_APPROX(m1_rb(i, j), m1(rows - 1 - i, cols - 1 - j));
51    }
52  }
53
54  Reverse<MatrixType, Vertical> m1_rv(m1);
55  // Verify that a Reverse in the vertical directions of an expression works
56  for ( int i = 0; i < rows; i++ ) {
57    for ( int j = 0; j < cols; j++ ) {
58      VERIFY_IS_APPROX(m1_rv(i, j), m1(rows - 1 - i, j));
59    }
60  }
61
62  Reverse<MatrixType, Horizontal> m1_rh(m1);
63  // Verify that a Reverse in the horizontal directions of an expression works
64  for ( int i = 0; i < rows; i++ ) {
65    for ( int j = 0; j < cols; j++ ) {
66      VERIFY_IS_APPROX(m1_rh(i, j), m1(i, cols - 1 - j));
67    }
68  }
69
70  VectorType v1_r = v1.reverse();
71  // Verify that a VectorType::reverse() of an expression works
72  for ( int i = 0; i < rows; i++ ) {
73    VERIFY_IS_APPROX(v1_r(i), v1(rows - 1 - i));
74  }
75
76  MatrixType m1_cr = m1.colwise().reverse();
77  // Verify that PartialRedux::reverse() works (for colwise())
78  for ( int i = 0; i < rows; i++ ) {
79    for ( int j = 0; j < cols; j++ ) {
80      VERIFY_IS_APPROX(m1_cr(i, j), m1(rows - 1 - i, j));
81    }
82  }
83
84  MatrixType m1_rr = m1.rowwise().reverse();
85  // Verify that PartialRedux::reverse() works (for rowwise())
86  for ( int i = 0; i < rows; i++ ) {
87    for ( int j = 0; j < cols; j++ ) {
88      VERIFY_IS_APPROX(m1_rr(i, j), m1(i, cols - 1 - j));
89    }
90  }
91
92  Scalar x = internal::random<Scalar>();
93
94  Index r = internal::random<Index>(0, rows-1),
95        c = internal::random<Index>(0, cols-1);
96
97  m1.reverse()(r, c) = x;
98  VERIFY_IS_APPROX(x, m1(rows - 1 - r, cols - 1 - c));
99
100  /*
101  m1.colwise().reverse()(r, c) = x;
102  VERIFY_IS_APPROX(x, m1(rows - 1 - r, c));
103
104  m1.rowwise().reverse()(r, c) = x;
105  VERIFY_IS_APPROX(x, m1(r, cols - 1 - c));
106  */
107}
108
109void test_array_reverse()
110{
111  for(int i = 0; i < g_repeat; i++) {
112    CALL_SUBTEST_1( reverse(Matrix<float, 1, 1>()) );
113    CALL_SUBTEST_2( reverse(Matrix2f()) );
114    CALL_SUBTEST_3( reverse(Matrix4f()) );
115    CALL_SUBTEST_4( reverse(Matrix4d()) );
116    CALL_SUBTEST_5( reverse(MatrixXcf(3, 3)) );
117    CALL_SUBTEST_6( reverse(MatrixXi(6, 3)) );
118    CALL_SUBTEST_7( reverse(MatrixXcd(20, 20)) );
119    CALL_SUBTEST_8( reverse(Matrix<float, 100, 100>()) );
120    CALL_SUBTEST_9( reverse(Matrix<float,Dynamic,Dynamic,RowMajor>(6,3)) );
121  }
122#ifdef EIGEN_TEST_PART_3
123  Vector4f x; x << 1, 2, 3, 4;
124  Vector4f y; y << 4, 3, 2, 1;
125  VERIFY(x.reverse()[1] == 3);
126  VERIFY(x.reverse() == y);
127#endif
128}
129