Eigen  3.3.0
 
Loading...
Searching...
No Matches
MatrixBaseEigenvalues.h
1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
5// Copyright (C) 2010 Jitse Niesen <jitse@maths.leeds.ac.uk>
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#ifndef EIGEN_MATRIXBASEEIGENVALUES_H
12#define EIGEN_MATRIXBASEEIGENVALUES_H
13
14namespace Eigen {
15
16namespace internal {
17
18template<typename Derived, bool IsComplex>
19struct eigenvalues_selector
20{
21 // this is the implementation for the case IsComplex = true
22 static inline typename MatrixBase<Derived>::EigenvaluesReturnType const
23 run(const MatrixBase<Derived>& m)
24 {
25 typedef typename Derived::PlainObject PlainObject;
26 PlainObject m_eval(m);
27 return ComplexEigenSolver<PlainObject>(m_eval, false).eigenvalues();
28 }
29};
30
31template<typename Derived>
32struct eigenvalues_selector<Derived, false>
33{
34 static inline typename MatrixBase<Derived>::EigenvaluesReturnType const
35 run(const MatrixBase<Derived>& m)
36 {
37 typedef typename Derived::PlainObject PlainObject;
38 PlainObject m_eval(m);
39 return EigenSolver<PlainObject>(m_eval, false).eigenvalues();
40 }
41};
42
43} // end namespace internal
44
65template<typename Derived>
66inline typename MatrixBase<Derived>::EigenvaluesReturnType
68{
69 typedef typename internal::traits<Derived>::Scalar Scalar;
70 return internal::eigenvalues_selector<Derived, NumTraits<Scalar>::IsComplex>::run(derived());
71}
72
87template<typename MatrixType, unsigned int UpLo>
90{
91 typedef typename SelfAdjointView<MatrixType, UpLo>::PlainObject PlainObject;
92 PlainObject thisAsMatrix(*this);
93 return SelfAdjointEigenSolver<PlainObject>(thisAsMatrix, false).eigenvalues();
94}
95
96
97
120template<typename Derived>
121inline typename MatrixBase<Derived>::RealScalar
123{
124 using std::sqrt;
125 typename Derived::PlainObject m_eval(derived());
126 // FIXME if it is really guaranteed that the eigenvalues are already sorted,
127 // then we don't need to compute a maxCoeff() here, comparing the 1st and last ones is enough.
128 return sqrt((m_eval*m_eval.adjoint())
129 .eval()
130 .template selfadjointView<Lower>()
131 .eigenvalues()
132 .maxCoeff()
133 );
134}
135
151template<typename MatrixType, unsigned int UpLo>
154{
155 return eigenvalues().cwiseAbs().maxCoeff();
156}
157
158} // end namespace Eigen
159
160#endif
internal::traits< Derived >::Scalar Scalar
Definition: DenseBase.h:66
Base class for all dense matrices, vectors, and expressions.
Definition: MatrixBase.h:50
The matrix class, also used for vectors and row-vectors.
Definition: Matrix.h:180
Computes eigenvalues and eigenvectors of selfadjoint matrices.
Definition: SelfAdjointEigenSolver.h:71
const RealVectorType & eigenvalues() const
Returns the eigenvalues of given matrix.
Definition: SelfAdjointEigenSolver.h:282
Expression of a selfadjoint matrix from a triangular part of a dense matrix.
Definition: SelfAdjointView.h:51
NumTraits< Scalar >::Real RealScalar
Definition: SelfAdjointView.h:209
Namespace containing all symbols from the Eigen library.
Definition: Core:287