chrono::modal::ChQuadraticEigenvalueSolverNullspaceDirect Class Reference
Description
Solves the eigenvalue problem with a direct method: first does LU factorization of Cq jacobians to find the null space, then solves the problem using the direct Eigen::EigenSolver.
Note: since intermediate dense matrices are built, the performance is acceptable only for small-sized problems. Note: since the method is direct, all eigenvalues are computed, regardless of n_modes, but only lower n_modes are returned.
#include <ChEigenvalueSolver.h>
Inheritance diagram for chrono::modal::ChQuadraticEigenvalueSolverNullspaceDirect:
Collaboration diagram for chrono::modal::ChQuadraticEigenvalueSolverNullspaceDirect:
Public Member Functions | |
| virtual bool | Solve (const ChSparseMatrix &M, const ChSparseMatrix &R, const ChSparseMatrix &K, const ChSparseMatrix &Cq, ChMatrixDynamic< std::complex< double >> &V, ChVectorDynamic< std::complex< double >> &eig, ChVectorDynamic< double > &freq, ChVectorDynamic< double > &damping_ratio, ChEigenvalueSolverSettings settings=0) const override |
| Solve the quadratic eigenvalue problem (lambda^2*M + lambda*R + K)*x = 0 s.t. More... | |
Member Function Documentation
◆ Solve()
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overridevirtual |
Solve the quadratic eigenvalue problem (lambda^2*M + lambda*R + K)*x = 0 s.t.
Cq*x = 0 If n_modes=0, return all eigenvalues, otherwise only the first lower n_modes.
- Parameters
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M input M matrix R input R matrix K input K matrix Cq input Cq matrix of constraint jacobians V output matrix with eigenvectors as columns, will be resized eig output vector with complex eigenvalues (real part not zero if some damping), will be resized freq output vector with n frequencies [Hz], as f=w/(2*PI), will be resized. damping_ratio output vector with n damping rations r=damping/critical_damping. settings optional: settings for the solver, or n. of desired lower eigenvalues. If =0, return all eigenvalues.
Implements chrono::modal::ChQuadraticEigenvalueSolver.
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
