/*@C
SNESMonitorSetRatio - Sets SNES to use a monitor that prints the
ratio of the function norm at each iteration.
Collective on SNES
Input Parameters:
+ snes - the SNES context
- viewer - ASCII viewer to print output
Level: intermediate
.keywords: SNES, nonlinear, monitor, norm
.seealso: SNESMonitorSet(), SNESMonitorSolution(), SNESMonitorDefault()
@*/
PetscErrorCode SNESMonitorSetRatio(SNES snes,PetscViewer viewer)
{
PetscErrorCode ierr;
SNESMonitorRatioContext *ctx;
PetscReal *history;
PetscFunctionBegin;
ierr = PetscNewLog(snes,&ctx);CHKERRQ(ierr);
ierr = SNESGetConvergenceHistory(snes,&history,NULL,NULL);CHKERRQ(ierr);
if (!history) {
ierr = PetscMalloc1(100,&ctx->history);CHKERRQ(ierr);
ierr = SNESSetConvergenceHistory(snes,ctx->history,0,100,PETSC_TRUE);CHKERRQ(ierr);
}
ctx->viewer = viewer;
ierr = SNESMonitorSet(snes,SNESMonitorRatio,ctx,SNESMonitorRatioDestroy);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
/*@C
SNESMonitorRatio - Monitors progress of the SNES solvers by printing the ratio
of residual norm at each iteration to the previous.
Collective on SNES
Input Parameters:
+ snes - the SNES context
. its - iteration number
. fgnorm - 2-norm of residual (or gradient)
- dummy - context of monitor
Level: intermediate
.keywords: SNES, nonlinear, monitor, norm
.seealso: SNESMonitorSet(), SNESMonitorSolution()
@*/
PetscErrorCode SNESMonitorRatio(SNES snes,PetscInt its,PetscReal fgnorm,void *dummy)
{
PetscErrorCode ierr;
PetscInt len;
PetscReal *history;
SNESMonitorRatioContext *ctx = (SNESMonitorRatioContext*)dummy;
PetscFunctionBegin;
ierr = SNESGetConvergenceHistory(snes,&history,PETSC_NULL,&len);CHKERRQ(ierr);
ierr = PetscViewerASCIIAddTab(ctx->viewer,((PetscObject)snes)->tablevel);CHKERRQ(ierr);
if (!its || !history || its > len) {
ierr = PetscViewerASCIIPrintf(ctx->viewer,"%3D SNES Function norm %14.12e \n",its,(double)fgnorm);CHKERRQ(ierr);
} else {
PetscReal ratio = fgnorm/history[its-1];
ierr = PetscViewerASCIIPrintf(ctx->viewer,"%3D SNES Function norm %14.12e %14.12e \n",its,(double)fgnorm,(double)ratio);CHKERRQ(ierr);
}
ierr = PetscViewerASCIISubtractTab(ctx->viewer,((PetscObject)snes)->tablevel);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
/*@C
SNESMonitorSetRatio - Sets SNES to use a monitor that prints the
ratio of the function norm at each iteration.
Collective on SNES
Input Parameters:
+ snes - the SNES context
- viewer - ASCII viewer to print output
Level: intermediate
.keywords: SNES, nonlinear, monitor, norm
.seealso: SNESMonitorSet(), SNESMonitorSolution(), SNESMonitorDefault()
@*/
PetscErrorCode SNESMonitorSetRatio(SNES snes,PetscViewer viewer)
{
PetscErrorCode ierr;
SNESMonitorRatioContext *ctx;
PetscReal *history;
PetscFunctionBegin;
if (!viewer) {
ierr = PetscViewerASCIIOpen(((PetscObject)snes)->comm,"stdout",&viewer);CHKERRQ(ierr);
ierr = PetscObjectReference((PetscObject)viewer);CHKERRQ(ierr);
}
ierr = PetscNewLog(snes,SNESMonitorRatioContext,&ctx);CHKERRQ(ierr);
ierr = SNESGetConvergenceHistory(snes,&history,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
if (!history) {
ierr = PetscMalloc(100*sizeof(PetscReal),&ctx->history);CHKERRQ(ierr);
ierr = SNESSetConvergenceHistory(snes,ctx->history,0,100,PETSC_TRUE);CHKERRQ(ierr);
}
ctx->viewer = viewer;
ierr = SNESMonitorSet(snes,SNESMonitorRatio,ctx,SNESMonitorRatioDestroy);CHKERRQ(ierr);
PetscFunctionReturn(0);
}