petsc-3.3-p7 2013-05-11

TSAlphaSetRadius

sets the desired spectral radius of the method (i.e. high-frequency numerical damping)

Synopsis

#include "petscts.h"   
PetscErrorCode  TSAlphaSetRadius(TS ts,PetscReal radius)

Logically Collective on TS

The algorithmic parameters \alpha_m and \alpha_f of the generalized-\alpha method can be computed in terms of a specified spectral radius \rho in [0,1] for infinite time step in order to

control high-frequency numerical damping

alpha_m = 0.5*(3-\rho)/(1+\rho) alpha_f = 1/(1+\rho)

Input Parameter

	ts	- timestepping context
	radius	- the desired spectral radius

Options Database

-ts_alpha_radius <radius> -

Examples