petsc-3.6.2 2015-10-02
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sets the algorithmic parameters for TSALPHA


#include "petscts.h"   
PetscErrorCode  TSAlphaSetParams(TS ts,PetscReal alpha_m,PetscReal alpha_f,PetscReal gamma)
Not Collective

Second-order accuracy can be obtained so long as

\gamma = 0.5 + alpha_m - alpha_f

Unconditional stability requires

\alpha_m >= \alpha_f >= 0.5

Backward Euler method is recovered when

\alpha_m = \alpha_f = gamma = 1

Input Parameter

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

Options Database

-ts_alpha_alpha_m <alpha_m>- . -ts_alpha_alpha_f <alpha_f>
-ts_alpha_gamma <gamma>- Note: Use of this function is normally only required to hack TSALPHA to use a modified integration scheme. Users should call TSAlphaSetRadius() to set the desired spectral radius of the methods (i.e. high-frequency damping) in order so select optimal values for these parameters.

See Also

TSAlphaSetRadius(), TSAlphaGetParams()

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