slepc-3.22.1 2024-10-28

EPSEVSLSetDOSParameters

Defines the parameters used for computing the density of states (DOS) in the EVSL solver.

Synopsis

#include "slepceps.h" 
PetscErrorCode EPSEVSLSetDOSParameters(EPS eps,EPSEVSLDOSMethod dos,PetscInt nvec,PetscInt deg,PetscInt steps,PetscInt npoints)

Logically Collective

Input Parameters

	eps	- the eigensolver context
	dos	- DOS method, either KPM or Lanczos
	nvec	- number of sample vectors
	deg	- polynomial degree (KPM only)
	steps	- number of Lanczos steps (Lanczos only)
	npoints	- number of sample points (Lanczos only)

Options Database Keys

	-eps_evsl_dos_method <dos>	- set the DOS method, either kpm or lanczos
	-eps_evsl_dos_nvec <n>	- set the number of sample vectors
	-eps_evsl_dos_degree <n>	- set the polynomial degree
	-eps_evsl_dos_steps <n>	- set the number of Lanczos steps
	-eps_evsl_dos_npoints <n>	- set the number of sample points

Notes

The density of states (or spectral density) can be approximated with two methods, kernel polynomial method (KPM) or Lanczos. Some parameters for these methods can be set by the user with this function, with some of them being relevant for one of the methods only.

For the integer argumens, you can use PETSC_CURRENT to keep the current value, and PETSC_DETERMINE to set them to a reasonable default.

Level

intermediate

Location

src/eps/impls/external/evsl/evsl.c

Index of all EPS routines
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Index of all manual pages