12.5 Eigenvalue Solution

EIGENVALUE_SOLUTION

EIGENVALUE_SOLUTION Eigensolver_name = list, etc...

Specify the type of eigenvalue solver to use for all equations in all subdomains/element groups belonging to any given solution stagger.

Note	Variable Name	Type	Default	Description
	Number_of_eigenpairs	integer	[0]	Number of eigenpairs requested
	Step_number	integer	[0]	Step number at which eigensolution is to be
				initiated.
	Frequency	integer	[1]	Eigensolution frequency
(1)	Eigensolver_name	list	[*]	Eigenvalue solution procedure:
	determinant_Search			Determinant Search solver
	subspace_Iterations			Subspace Iterations solver
	block_Lanczos_num_type			Block Lanczos solver; number type problem
	block_Lanczos_int_type			Block Lanczos solver; interval type problem
	Equation_type	list	[*]	Equation type (see Chapter 9 for details)
	elliptic			Elliptic problem
	parabolic			Parabolic problem
	hyperbolic			Hyperbolic problem
• Block Lanczos Interval Type Problems
	Lowest_eigenvalue	real	[0.0]	Specify lowest eigenvalue of the interval
	Highest_eigenvalue	real	[0.0]	Specify highest eigenvalue of the interval
• Block Lanczos Number Type Problems
	Select_lowest_eigen	list	[on]	Compute lowest eigenvalues
	on / off
	Select_highest_eigen	list	[off]	Compute highest eigenvalues
	on / off
	Spectrum_inversion	list	[on]	Spectrum inversion option
	on / off
• Block Lanczos Option
	Diagonal_mass	list	[on]	Diagonal mass matrix
	on / off
	Consistent_mass	list	[off]	Consistent mass matrix
	on / off

Notes/

(1) Implementation restricted to symmetric eigenvalue problems.

References / Bibliography

1. Bathe, K.J. and E.L. Wilson, Numerical Methods in Finite Element Analysis, Prentice Hall, Englewood Cliffs, NJ, (1976).

2. Parlett, B.N., The Symmetric Eigenvalue Problem, Prentice-Hall, Englewood Cliffs, N.J., (1980).

3. Parlett, B.N. and D.S. Scott,"The Lanczos Algorithm with Selective Orthogonalization," Mathematics of Computation, 33, 145, (1979), 217-238.