SNESConvergedCorrectPressure

The regular SNES convergence test that, up on convergence, adds a vector in the nullspace to make the continuum integral of the pressure field equal to zero.

Synopsis

#include "petscdmplex.h" 
#include "petscsnes.h"   
PetscErrorCode SNESConvergedCorrectPressure(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *ctx)

Logically Collective

Input Parameters

• snes - the SNES context

• it - the iteration (0 indicates before any Newton steps)

• xnorm - 2-norm of current iterate

• gnorm - 2-norm of current step

• f - 2-norm of function at current iterate

• ctx - Optional user context

Output Parameter

• reason - SNES_CONVERGED_ITERATING, SNES_CONVERGED_ITS, or SNES_DIVERGED_FNORM_NAN

Options Database Key

• -snes_convergence_test correct_pressure - see SNESSetFromOptions()

Notes

In order to use this convergence test, you must set up several PETSc structures. First fields must be added to the DM, and a PetscDS must be created with discretizations of those fields. We currently assume that the pressure field has index 1. The pressure field must have a nullspace, likely created using the DMSetNullSpaceConstructor() interface. Last we must be able to integrate the pressure over the domain, so the DM attached to the SNES must be a DMPLEX at this time.

Developer Note

This is a total misuse of the SNES convergence test handling system. It should be removed. Perhaps a SNESSetPostSolve() could be constructed to handle this process.

See Also

SNES: Nonlinear Solvers, SNES, DM, SNESConvergedDefault(), SNESSetConvergenceTest(), DMSetNullSpaceConstructor()

Level

advanced

Location

src/snes/utils/dmplexsnes.c

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Index of all SNES routines
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