chrono::modal::ChGeneralizedEigenvalueSolver< ScalarT > Class Template Reference

Description

template<typename ScalarT>
class chrono::modal::ChGeneralizedEigenvalueSolver< ScalarT >

Base interface class for generalized eigenvalue solvers A*x = lambda*B*x.

Currently it is implied that the derived eigensolvers are iterative.

#include <ChGeneralizedEigenvalueSolver.h>

Collaboration diagram for chrono::modal::ChGeneralizedEigenvalueSolver< ScalarT >:

Public Types
using	ScalarType = ScalarT

Public Member Functions
double	GetTimeMatrixAssembly () const
	Get cumulative time for matrix assembly.
double	GetTimeEigenSetup () const
	Get cumulative time for the eigensolver setup.
double	GetTimeEigenSolver () const
	Get cumulative time for the eigensolver solution.
double	GetTimeSolutionPostProcessing () const
	Get cumulative time for post-solver solution postprocessing.

Static Public Member Functions
static void	SortRitzPairs (ChVectorDynamic< ScalarType > &eigvals, ChMatrixDynamic< ScalarType > &eigvects, std::function< bool(const ChVectorDynamic< ScalarType > &, int, int)> ordering_fun=[](const ChVectorDynamic< std::complex< double >> &eigv, int a, int b) { return std::abs(eigv(a))< std::abs(eigv(b));})
	Sort the eigenvalues and eigenvectors in the order specified by the ordering function in-place.
static double	GetMaxResidual (const ChSparseMatrix &A, const ChSparseMatrix &B, const ChMatrixDynamic< ScalarType > &eigvects, const ChVectorDynamic< ScalarType > &eigvals)
static double	GetMaxResidual (const ChSparseMatrix &K, const ChSparseMatrix &M, const ChSparseMatrix &Cq, const ChMatrixDynamic< ScalarType > &eigvects, const ChVectorDynamic< ScalarType > &eigvals)
static double	GetMaxResidual (const ChSparseMatrix &K, const ChSparseMatrix &R, const ChSparseMatrix &M, const ChSparseMatrix &Cq, const ChMatrixDynamic< ScalarType > &eigvects, const ChVectorDynamic< ScalarType > &eigvals)
static double	BuildUndampedSystem (const ChSparseMatrix &M, const ChSparseMatrix &K, const ChSparseMatrix &Cq, ChSparseMatrix &A, ChSparseMatrix &B, bool scaleCq)
	Build the quadratic eigenvalue problem matrix for the undamped case. More...
static double	BuildDampedSystem (const ChSparseMatrix &M, const ChSparseMatrix &R, const ChSparseMatrix &K, const ChSparseMatrix &Cq, ChSparseMatrix &A, ChSparseMatrix &B, bool scaleCq)
	Build the quadratic eigenvalue problem matrix for the damped case. More...
static void	InsertUniqueRitzPairs (const ChVectorDynamic< ScalarType > &eigvals_source, const ChMatrixDynamic< ScalarType > &eigvects_source, ChVectorDynamic< ScalarType > &eigvals_total, ChMatrixDynamic< ScalarType > &eigvects_total, std::function< double(ScalarType)> freq_from_eigval_fun, int &found_eigs, int num_eigvals_source, double equal_freq_tolerance=1e-4)
	Add unique ritz pairs to a wider set of ritz pairs. More...

Public Attributes
double	tolerance = 1e-6
	tolerance for the iterative solver.
int	max_iterations = 500
	upper limit for the number of iterations. If too low might not converge.
bool	verbose = false
	turn to true to see some diagnostic.
bool	sort_ritz_pairs = true
	sort the eigenvalues based on the smallest absolute value

Static Protected Member Functions
static Eigen::PermutationMatrix< Eigen::Dynamic, Eigen::Dynamic >	GetPermutationMatrix (int num_elements, std::function< bool(int, int)> ordering_fun)
	Returns the permutation matrix to sort the given elements based on the ordering function.

Protected Attributes
ChTimer	m_timer_matrix_assembly
	timer for matrix assembly
ChTimer	m_timer_eigen_setup
	timer for eigensolver setup
ChTimer	m_timer_eigen_solver
	timer for eigensolver solution
ChTimer	m_timer_solution_postprocessing
	timer for conversion of eigensolver solution
const int	m_min_subspace_size = 30

Friends
template<typename EigSolverType >
int	Solve (EigSolverType &eig_solver, ChSparseMatrix &A, ChSparseMatrix &B, ChMatrixDynamic< typename EigSolverType::ScalarType > &eigvects, ChVectorDynamic< typename EigSolverType::ScalarType > &eigvals, const std::list< std::pair< int, typename EigSolverType::ScalarType >> &eig_requests, bool uniquify, int eigvects_clipping_length)

Member Function Documentation

BuildDampedSystem()

template<typename ScalarT>

static double chrono::modal::ChGeneralizedEigenvalueSolver< ScalarT >::BuildDampedSystem ( const ChSparseMatrix &  M, const ChSparseMatrix &  R, const ChSparseMatrix &  K, const ChSparseMatrix &  Cq, ChSparseMatrix &  A, ChSparseMatrix &  B, bool  scaleCq  )

inlinestatic

Build the quadratic eigenvalue problem matrix for the damped case.

The optional scaling of the Cq matrix improves the conditioning of the eigenvalue problem. If enabled, the user must take care of rescaling back the eigenvectors; e.g. eigvects.bottomRows(Cq.rows()) *= scaling The scaling value is returned by the function.

BuildUndampedSystem()

template<typename ScalarT>

static double chrono::modal::ChGeneralizedEigenvalueSolver< ScalarT >::BuildUndampedSystem ( const ChSparseMatrix &  M, const ChSparseMatrix &  K, const ChSparseMatrix &  Cq, ChSparseMatrix &  A, ChSparseMatrix &  B, bool  scaleCq  )

inlinestatic

Build the quadratic eigenvalue problem matrix for the undamped case.

The optional scaling of the Cq matrix improves the conditioning of the eigenvalue problem. If enabled, the user must take care of rescaling back the eigenvectors; e.g. eigvects.bottomRows(Cq.rows()) *= scaling The scaling value is returned by the function.

InsertUniqueRitzPairs()

template<typename ScalarT>

static void chrono::modal::ChGeneralizedEigenvalueSolver< ScalarT >::InsertUniqueRitzPairs ( const ChVectorDynamic< ScalarType > &  eigvals_source, const ChMatrixDynamic< ScalarType > &  eigvects_source, ChVectorDynamic< ScalarType > &  eigvals_total, ChMatrixDynamic< ScalarType > &  eigvects_total, std::function< double(ScalarType)>  freq_from_eigval_fun, int &  found_eigs, int  num_eigvals_source, double  equal_freq_tolerance = 1e-4  )

inlinestatic

Add unique ritz pairs to a wider set of ritz pairs.

The ('eigvals_source', 'eigvects_source') are going to be added to the ('eigvals_total', 'eigvects_total') set only if the frequency of the modes are unique with respect to the ones already stored. The 'freq_from_eigval_fun' function is used to extract the frequency from the eigenvalues. 'found_eigs' is the number of eigenvalues already stored in the ('eigvals_total', 'eigvects_total') set. Most of the times is equal to eigvects_total.cols(), but it might be less if some exceeding eigenvalues have been found. Similar consideration for 'num_eigvals_source'. 'equal_freq_tolerance' is the tolerance used to consider two frequencies as equal.

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The documentation for this class was generated from the following file:

• /builds/uwsbel/chrono/src/chrono_modal/ChGeneralizedEigenvalueSolver.h