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 
14 using namespace std;
15 
reverse(const MatrixType & m)16 template<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 
test_array_reverse()109 void 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