chrono::modal::ChGeneralizedEigenvalueSolverLanczos Class Reference

Description

Solves the undamped constrained eigenvalue problem with the Lanczos iterative method.

It assumes that K and M matrices are symmetric, hence a real eigenvalue problem. This is an efficient method to compute only the lower n modes, ex. when there are so many degreees of freedom that it would make a full solution impossible. It uses an iterative method and it exploits the sparsity of the matrices.

#include <ChEigenvalueSolver.h>

Inheritance diagram for chrono::modal::ChGeneralizedEigenvalueSolverLanczos:
Collaboration diagram for chrono::modal::ChGeneralizedEigenvalueSolverLanczos:

Public Member Functions

virtual bool Solve (const ChSparseMatrix &M, const ChSparseMatrix &K, const ChSparseMatrix &Cq, ChMatrixDynamic< std::complex< double >> &V, ChVectorDynamic< std::complex< double >> &eig, ChVectorDynamic< double > &freq, ChEigenvalueSolverSettings settings=0) const override
 Solve the constrained eigenvalue problem (-wsquare*M + K)*x = 0 s.t. More...
 

Member Function Documentation

◆ Solve()

bool chrono::modal::ChGeneralizedEigenvalueSolverLanczos::Solve ( const ChSparseMatrix M,
const ChSparseMatrix K,
const ChSparseMatrix Cq,
ChMatrixDynamic< std::complex< double >> &  V,
ChVectorDynamic< std::complex< double >> &  eig,
ChVectorDynamic< double > &  freq,
ChEigenvalueSolverSettings  settings = 0 
) const
overridevirtual

Solve the constrained eigenvalue problem (-wsquare*M + K)*x = 0 s.t.

Cq*x = 0 If n_modes=0, return all eigenvalues, otherwise only the first lower n_modes.

Parameters
Minput M matrix, n_v x n_v
Kinput K matrix, n_v x n_v
Cqinput Cq matrix of constraint jacobians, n_c x n_v
Voutput matrix n x n_v with eigenvectors as columns, will be resized
eigoutput vector with n eigenvalues, will be resized.
freqoutput vector with n frequencies [Hz], as f=w/(2*PI), will be resized.
settingsoptional: settings for the solver, or n. of desired lower eigenvalues. If =0, return all eigenvalues.

Implements chrono::modal::ChGeneralizedEigenvalueSolver.


The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono_modal/ChEigenvalueSolver.h
  • /builds/uwsbel/chrono/src/chrono_modal/ChEigenvalueSolver.cpp