TSAlphaSetRadius#

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

Synopsis#

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

Logically Collective

Input Parameters#

  • ts - timestepping context

  • radius - the desired spectral radius

Options Database Key#

  • -ts_alpha_radius - set alpha radius

Notes#

The algorithmic parameters αm\alpha_m and αf\alpha_f of the generalized-α\alpha method can be computed in terms of a specified spectral radius ρ\rho in [0, 1] for infinite time step in order to control high-frequency numerical damping:

αm=0.5∗(3−ρ)/(1+ρ)αf=1/(1+ρ) \begin{align*} \alpha_m = 0.5*(3-\rho)/(1+\rho) \\ \alpha_f = 1/(1+\rho) \end{align*}

See Also#

TS: Scalable ODE and DAE Solvers, TS, TSALPHA, TSAlphaSetParams(), TSAlphaGetParams()

Level#

intermediate

Location#

src/ts/impls/implicit/alpha/alpha1.c

Implementations#

TSAlphaSetRadius_Alpha() in src/ts/impls/implicit/alpha/alpha1.c

Index of all TS routines
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Index of all manual pages