petsc-3.10.5 2019-03-28

TSAlpha2SetParams

sets the algorithmic parameters for TSALPHA2

Synopsis

#include "petscts.h"   
PetscErrorCode TSAlpha2SetParams(TS ts,PetscReal alpha_m,PetscReal alpha_f,PetscReal gamma,PetscReal beta)

Logically Collective on TS

Second-order accuracy can be obtained so long as

\gamma = 1/2 + alpha_m - alpha_f \beta = 1/4 (1 + alpha_m - alpha_f)^2

Unconditional stability requires

\alpha_m >= \alpha_f >= 1/2

Input Parameter

	ts	- timestepping context
	\alpha_m	- algorithmic paramenter
	\alpha_f	- algorithmic paramenter
	\gamma	- algorithmic paramenter
	\beta	- algorithmic paramenter

Options Database

Note

Use of this function is normally only required to hack TSALPHA2 to use a modified integration scheme. Users should call TSAlpha2SetRadius() to set the desired spectral radius of the methods (i.e. high-frequency damping) in order so select optimal values for these parameters.

Level

advanced

Location

src/ts/impls/implicit/alpha/alpha2.c

Implementations

TSAlpha2SetParams_Alpha in src/ts/impls/implicit/alpha/alpha2.c

Index of all TS routines
Table of Contents for all manual pages
Index of all manual pages

	-ts_alpha_alpha_m <alpha_m>	- . -ts_alpha_alpha_f <alpha_f>
	-ts_alpha_gamma <gamma>	- - -ts_alpha_beta <beta>