KSPMonitorSet

Sets an ADDITIONAL function to be called at every iteration to monitor the residual/error etc.

Synopsis

#include "petscksp.h" 
#include "petscmat.h" 
PetscErrorCode KSPMonitorSet(KSP ksp, PetscErrorCode (*monitor)(KSP, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))

Logically Collective

Input Parameters

• ksp - iterative context obtained from KSPCreate()

• monitor - pointer to function (if this is NULL, it turns off monitoring

• mctx - [optional] context for private data for the monitor routine (use NULL if no context is desired)

• monitordestroy - [optional] routine that frees monitor context (may be NULL)

Calling Sequence of monitor

PetscErrorCode  monitor(KSP ksp, PetscInt it, PetscReal rnorm, void *mctx)

• ksp - iterative context obtained from KSPCreate()

• it - iteration number

• rnorm - (estimated) 2-norm of (preconditioned) residual

• mctx - optional monitoring context, as set by KSPMonitorSet()

Calling Sequence of monitordestroy

PetscErrorCode destroy(void *mctx)

Options Database Keys

• -ksp_monitor - sets KSPMonitorResidual()

• -ksp_monitor draw - sets KSPMonitorResidualDraw() and plots residual

• -ksp_monitor draw::draw_lg - sets KSPMonitorResidualDrawLG() and plots residual

• -ksp_monitor_pause_final - Pauses any graphics when the solve finishes (only works for internal monitors)

• -ksp_monitor_true_residual - sets KSPMonitorTrueResidual()

• -ksp_monitor_true_residual draw::draw_lg - sets KSPMonitorTrueResidualDrawLG() and plots residual

• -ksp_monitor_max - sets KSPMonitorTrueResidualMax()

• -ksp_monitor_singular_value - sets KSPMonitorSingularValue()

• -ksp_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to KSPMonitorSet(), but does not cancel those set via the options database.

Notes

The default is to do nothing. To print the residual, or preconditioned residual if KSPSetNormType(ksp,KSP_NORM_PRECONDITIONED) was called, use KSPMonitorResidual() as the monitoring routine, with a PETSCVIEWERASCII as the context.

Several different monitoring routines may be set by calling KSPMonitorSet() multiple times; all will be called in the order in which they were set.

Fortran Notes

Only a single monitor function can be set for each KSP object

See Also

KSP: Linear System Solvers, KSPMonitorResidual(), KSPMonitorCancel(), KSP

Level

beginner

Location

src/ksp/ksp/interface/itfunc.c

Examples

src/ksp/ksp/tutorials/ex2f.F90
src/ksp/ksp/tutorials/ex42.c
src/ksp/ksp/tutorials/ex9.c
src/snes/tutorials/ex30.c
src/ts/tutorials/ex47.c

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