TSARKIMEX#

ODE and DAE solver using additive Runge-Kutta IMEX schemes These methods are intended for problems with well-separated time scales, especially when a slow scale is strongly nonlinear such that it is expensive to solve with a fully implicit method. The user should provide the stiff part of the equation using TSSetIFunction() and the non-stiff part with TSSetRHSFunction().

Options Database Keys#

-ts_arkimex_type <1bee,a2,l2,ars122,2c,2d,2e,prssp2,3,bpr3,ars443,4,5> - Set TSARKIMEX scheme type
-ts_dirk_type - Set TSDIRK scheme type
-ts_arkimex_fully_implicit <true,false> - Solve both parts of the equation implicitly
-ts_arkimex_fastslowsplit <true,false> - Enables the TSARKIMEX solver for a fast-slow system where the RHS is split component-wise, see TSRHSSplitSetIS()
-ts_arkimex_initial_guess_extrapolate - Extrapolate the initial guess for the stage solution from stage values of the previous time step

Notes#

The default is TSARKIMEX3, it can be changed with TSARKIMEXSetType() or -ts_arkimex_type

If the equation is implicit or a DAE, then TSSetEquationType() needs to be set accordingly. Refer to the manual for further information.

Methods with an explicit stage can only be used with ODE in which the stiff part \( G(t,X,\dot{X}) \) has the form \( \dot{X} + \hat{G}(t,X)\).

Consider trying TSROSW if the stiff part is linear or weakly nonlinear.

Level#

beginner

Location#

src/ts/impls/arkimex/arkimex.c

Examples#

src/ts/tutorials/ex31.c
src/ts/tutorials/ex36.c
src/ts/tutorials/extchem.c
src/ts/tutorials/ex29.c
src/ts/tutorials/ex20adj.c
src/ts/tutorials/ex22f_mf.F90
src/ts/tutorials/extchemfield.c
src/ts/tutorials/ex22.c
src/ts/tutorials/ex22f.F90
src/ts/tutorials/ex35.cxx

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