GenEigsRealShiftSolver.h
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1 // Copyright (C) 2016-2019 Yixuan Qiu <yixuan.qiu@cos.name>
2 //
3 // This Source Code Form is subject to the terms of the Mozilla
4 // Public License v. 2.0. If a copy of the MPL was not distributed
5 // with this file, You can obtain one at https://mozilla.org/MPL/2.0/.
6 
7 #ifndef GEN_EIGS_REAL_SHIFT_SOLVER_H
8 #define GEN_EIGS_REAL_SHIFT_SOLVER_H
9 
10 #include <Eigen/Core>
11 
12 #include "GenEigsBase.h"
13 #include "Util/SelectionRule.h"
15 
16 namespace Spectra {
17 
38 template <typename Scalar = double,
39  int SelectionRule = LARGEST_MAGN,
40  typename OpType = DenseGenRealShiftSolve<double> >
41 class GenEigsRealShiftSolver : public GenEigsBase<Scalar, SelectionRule, OpType, IdentityBOp>
42 {
43 private:
45  typedef std::complex<Scalar> Complex;
47 
48  const Scalar m_sigma;
49 
50  // First transform back the Ritz values, and then sort
51  void sort_ritzpair(int sort_rule)
52  {
53  // The eigenvalues we get from the iteration is nu = 1 / (lambda - sigma)
54  // So the eigenvalues of the original problem is lambda = 1 / nu + sigma
55  ComplexArray ritz_val_org = Scalar(1.0) / this->m_ritz_val.head(this->m_nev).array() + m_sigma;
56  this->m_ritz_val.head(this->m_nev) = ritz_val_org;
58  }
59 
60 public:
79  GenEigsRealShiftSolver(OpType* op, Index nev, Index ncv, Scalar sigma) :
80  GenEigsBase<Scalar, SelectionRule, OpType, IdentityBOp>(op, NULL, nev, ncv),
81  m_sigma(sigma)
82  {
83  this->m_op->set_shift(m_sigma);
84  }
85 };
86 
87 } // namespace Spectra
88 
89 #endif // GEN_EIGS_REAL_SHIFT_SOLVER_H
DenseGenRealShiftSolve.h
Spectra::GenEigsRealShiftSolver::sort_ritzpair
void sort_ritzpair(int sort_rule)
Definition: GenEigsRealShiftSolver.h:51
Eigen::Array
General-purpose arrays with easy API for coefficient-wise operations.
Definition: Array.h:45
sampling::sigma
static const double sigma
Definition: testGaussianBayesNet.cpp:170
Spectra::IdentityBOp
Definition: ArnoldiOp.h:90
Spectra::GenEigsRealShiftSolver::Complex
std::complex< Scalar > Complex
Definition: GenEigsRealShiftSolver.h:45
Spectra::GenEigsRealShiftSolver::Index
Eigen::Index Index
Definition: GenEigsRealShiftSolver.h:44
Spectra::GenEigsBase< double, LARGEST_MAGN, DenseGenRealShiftSolve< double >, IdentityBOp >::m_op
DenseGenRealShiftSolve< double > * m_op
Definition: GenEigsBase.h:61
Spectra::GenEigsRealShiftSolver
Definition: GenEigsRealShiftSolver.h:41
Spectra::DenseGenRealShiftSolve::set_shift
void set_shift(Scalar sigma)
Definition: DenseGenRealShiftSolve.h:66
Spectra::GenEigsBase
Definition: GenEigsBase.h:40
Spectra::LARGEST_MAGN
@ LARGEST_MAGN
Definition: SelectionRule.h:32
Spectra::GenEigsBase::sort_ritzpair
virtual void sort_ritzpair(int sort_rule)
Definition: GenEigsBase.h:214
SelectionRule.h
Spectra
Definition: LOBPCGSolver.h:19
Spectra::GenEigsRealShiftSolver::m_sigma
const Scalar m_sigma
Definition: GenEigsRealShiftSolver.h:48
NULL
#define NULL
Definition: ccolamd.c:609
Spectra::GenEigsBase< double, LARGEST_MAGN, DenseGenRealShiftSolve< double >, IdentityBOp >::m_ritz_val
ComplexVector m_ritz_val
Definition: GenEigsBase.h:71
Spectra::GenEigsBase< double, LARGEST_MAGN, DenseGenRealShiftSolve< double >, IdentityBOp >::m_nev
const Index m_nev
Definition: GenEigsBase.h:64
Spectra::GenEigsRealShiftSolver::GenEigsRealShiftSolver
GenEigsRealShiftSolver(OpType *op, Index nev, Index ncv, Scalar sigma)
Definition: GenEigsRealShiftSolver.h:79
Spectra::GenEigsRealShiftSolver::ComplexArray
Eigen::Array< Complex, Eigen::Dynamic, 1 > ComplexArray
Definition: GenEigsRealShiftSolver.h:46
Scalar
SCALAR Scalar
Definition: bench_gemm.cpp:46
Eigen::Index
EIGEN_DEFAULT_DENSE_INDEX_TYPE Index
The Index type as used for the API.
Definition: Meta.h:74
GenEigsBase.h


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autogenerated on Sun Dec 22 2024 04:11:34