petsc-3.8.4 2018-03-24
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TSComputeIFunctionLinear

Evaluate the left hand side via the user-provided Jacobian, for linear problems only

Synopsis

#include "petscts.h"  
PetscErrorCode TSComputeIFunctionLinear(TS ts,PetscReal t,Vec U,Vec Udot,Vec F,void *ctx)
Collective on TS

Input Arguments

ts - time stepping context
t - time at which to evaluate
U - state at which to evaluate
Udot - time derivative of state vector
ctx - context

Output Arguments

F -left hand side

Notes

The assumption here is that the left hand side is of the form A*Udot (and not A*Udot + B*U). For other cases, the user is required to write their own TSComputeIFunction. This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems. The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().

Note that using this function is NOT equivalent to using TSComputeRHSFunctionLinear() since that solves Udot = A U

See Also

TSSetIFunction(), TSSetIJacobian(), TSComputeIJacobianConstant(), TSComputeRHSFunctionLinear()

Level:intermediate
Location:
src/ts/interface/ts.c
Index of all TS routines
Table of Contents for all manual pages
Index of all manual pages