xref: /aosp_15_r20/external/eigen/test/inverse.cpp (revision bf2c37156dfe67e5dfebd6d394bad8b2ab5804d4)
1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2008 Gael Guennebaud <[email protected]>
5 // Copyright (C) 2008 Benoit Jacob <[email protected]>
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 <Eigen/LU>
13 
14 template<typename MatrixType>
inverse_for_fixed_size(const MatrixType &,typename internal::enable_if<MatrixType::SizeAtCompileTime==Dynamic>::type * =0)15 void inverse_for_fixed_size(const MatrixType&, typename internal::enable_if<MatrixType::SizeAtCompileTime==Dynamic>::type* = 0)
16 {
17 }
18 
19 template<typename MatrixType>
inverse_for_fixed_size(const MatrixType & m1,typename internal::enable_if<MatrixType::SizeAtCompileTime!=Dynamic>::type * =0)20 void inverse_for_fixed_size(const MatrixType& m1, typename internal::enable_if<MatrixType::SizeAtCompileTime!=Dynamic>::type* = 0)
21 {
22   using std::abs;
23 
24   MatrixType m2, identity = MatrixType::Identity();
25 
26   typedef typename MatrixType::Scalar Scalar;
27   typedef typename NumTraits<Scalar>::Real RealScalar;
28   typedef Matrix<Scalar, MatrixType::ColsAtCompileTime, 1> VectorType;
29 
30   //computeInverseAndDetWithCheck tests
31   //First: an invertible matrix
32   bool invertible;
33   Scalar det;
34 
35   m2.setZero();
36   m1.computeInverseAndDetWithCheck(m2, det, invertible);
37   VERIFY(invertible);
38   VERIFY_IS_APPROX(identity, m1*m2);
39   VERIFY_IS_APPROX(det, m1.determinant());
40 
41   m2.setZero();
42   m1.computeInverseWithCheck(m2, invertible);
43   VERIFY(invertible);
44   VERIFY_IS_APPROX(identity, m1*m2);
45 
46   //Second: a rank one matrix (not invertible, except for 1x1 matrices)
47   VectorType v3 = VectorType::Random();
48   MatrixType m3 = v3*v3.transpose(), m4;
49   m3.computeInverseAndDetWithCheck(m4, det, invertible);
50   VERIFY( m1.rows()==1 ? invertible : !invertible );
51   VERIFY_IS_MUCH_SMALLER_THAN(abs(det-m3.determinant()), RealScalar(1));
52   m3.computeInverseWithCheck(m4, invertible);
53   VERIFY( m1.rows()==1 ? invertible : !invertible );
54 
55   // check with submatrices
56   {
57     Matrix<Scalar, MatrixType::RowsAtCompileTime+1, MatrixType::RowsAtCompileTime+1, MatrixType::Options> m5;
58     m5.setRandom();
59     m5.topLeftCorner(m1.rows(),m1.rows()) = m1;
60     m2 = m5.template topLeftCorner<MatrixType::RowsAtCompileTime,MatrixType::ColsAtCompileTime>().inverse();
61     VERIFY_IS_APPROX( (m5.template topLeftCorner<MatrixType::RowsAtCompileTime,MatrixType::ColsAtCompileTime>()), m2.inverse() );
62   }
63 }
64 
inverse(const MatrixType & m)65 template<typename MatrixType> void inverse(const MatrixType& m)
66 {
67   /* this test covers the following files:
68      Inverse.h
69   */
70   Index rows = m.rows();
71   Index cols = m.cols();
72 
73   typedef typename MatrixType::Scalar Scalar;
74 
75   MatrixType m1(rows, cols),
76              m2(rows, cols),
77              identity = MatrixType::Identity(rows, rows);
78   createRandomPIMatrixOfRank(rows,rows,rows,m1);
79   m2 = m1.inverse();
80   VERIFY_IS_APPROX(m1, m2.inverse() );
81 
82   VERIFY_IS_APPROX((Scalar(2)*m2).inverse(), m2.inverse()*Scalar(0.5));
83 
84   VERIFY_IS_APPROX(identity, m1.inverse() * m1 );
85   VERIFY_IS_APPROX(identity, m1 * m1.inverse() );
86 
87   VERIFY_IS_APPROX(m1, m1.inverse().inverse() );
88 
89   // since for the general case we implement separately row-major and col-major, test that
90   VERIFY_IS_APPROX(MatrixType(m1.transpose().inverse()), MatrixType(m1.inverse().transpose()));
91 
92   inverse_for_fixed_size(m1);
93 
94   // check in-place inversion
95   if(MatrixType::RowsAtCompileTime>=2 && MatrixType::RowsAtCompileTime<=4)
96   {
97     // in-place is forbidden
98     VERIFY_RAISES_ASSERT(m1 = m1.inverse());
99   }
100   else
101   {
102     m2 = m1.inverse();
103     m1 = m1.inverse();
104     VERIFY_IS_APPROX(m1,m2);
105   }
106 }
107 
108 template<typename Scalar>
inverse_zerosized()109 void inverse_zerosized()
110 {
111   Matrix<Scalar,Dynamic,Dynamic> A(0,0);
112   {
113     Matrix<Scalar,0,1> b, x;
114     x = A.inverse() * b;
115   }
116   {
117     Matrix<Scalar,Dynamic,Dynamic> b(0,1), x;
118     x = A.inverse() * b;
119     VERIFY_IS_EQUAL(x.rows(), 0);
120     VERIFY_IS_EQUAL(x.cols(), 1);
121   }
122 }
123 
EIGEN_DECLARE_TEST(inverse)124 EIGEN_DECLARE_TEST(inverse)
125 {
126   int s = 0;
127   for(int i = 0; i < g_repeat; i++) {
128     CALL_SUBTEST_1( inverse(Matrix<double,1,1>()) );
129     CALL_SUBTEST_2( inverse(Matrix2d()) );
130     CALL_SUBTEST_3( inverse(Matrix3f()) );
131     CALL_SUBTEST_4( inverse(Matrix4f()) );
132     CALL_SUBTEST_4( inverse(Matrix<float,4,4,DontAlign>()) );
133 
134     s = internal::random<int>(50,320);
135     CALL_SUBTEST_5( inverse(MatrixXf(s,s)) );
136     TEST_SET_BUT_UNUSED_VARIABLE(s)
137     CALL_SUBTEST_5( inverse_zerosized<float>() );
138     CALL_SUBTEST_5( inverse(MatrixXf(0, 0)) );
139     CALL_SUBTEST_5( inverse(MatrixXf(1, 1)) );
140 
141     s = internal::random<int>(25,100);
142     CALL_SUBTEST_6( inverse(MatrixXcd(s,s)) );
143     TEST_SET_BUT_UNUSED_VARIABLE(s)
144 
145     CALL_SUBTEST_7( inverse(Matrix4d()) );
146     CALL_SUBTEST_7( inverse(Matrix<double,4,4,DontAlign>()) );
147 
148     CALL_SUBTEST_8( inverse(Matrix4cd()) );
149   }
150 }
151