DMTSSetTransientVariable

sets function to transform from state to transient variables into a DMTS

Synopsis

#include "petscts.h" 
PetscErrorCode DMTSSetTransientVariable(DM dm, TSTransientVariableFn *tvar, void *ctx)

Logically Collective

Input Parameters

• dm - DM to be used with TS

• tvar - a function that transforms to transient variables, see TSTransientVariableFn for the calling sequence

• ctx - a context for tvar

Notes

Normally TSSetTransientVariable() is used

This is typically used to transform from primitive to conservative variables so that a time integrator (e.g., TSBDF) can be conservative. In this context, primitive variables P are used to model the state (e.g., because they lead to well-conditioned formulations even in limiting cases such as low-Mach or zero porosity). The transient variable is C(P), specified by calling this function. An IFunction thus receives arguments (P, Cdot) and the IJacobian must be evaluated via the chain rule, as in

\[ dF/dP + shift * dF/dCdot dC/dP. \]

See Also

TS: Scalable ODE and DAE Solvers, DMTS, TS, TSBDF, TSSetTransientVariable(), DMTSGetTransientVariable(), DMTSSetIFunction(), DMTSSetIJacobian(), TSTransientVariableFn

Level

developer

Location

src/ts/utils/dmts.c

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Index of all TS routines
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