SNESGetIterationNumber#

Gets the number of nonlinear iterations completed in the current or most recent SNESSolve()

Synopsis#

#include "petscsnes.h"  
PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)

Not Collective

Input Parameter#

snes - SNES context

Output Parameter#

iter - iteration number

Notes#

For example, during the computation of iteration 2 this would return 1.

This is useful for using lagged Jacobians (where one does not recompute the Jacobian at each SNES iteration). For example, the code

      ierr = SNESGetIterationNumber(snes,&it);
      if (!(it % 2)) {
        [compute Jacobian here]
      }

can be used in your function that computes the Jacobian to cause the Jacobian to be recomputed every second SNES iteration. See also SNESSetLagJacobian()

After the SNES solve is complete this will return the number of nonlinear iterations used.

Level#

intermediate

Location#

src/snes/interface/snes.c

Examples#

src/snes/tutorials/ex2.c
src/ts/tutorials/ex24.c
src/snes/tutorials/ex55.c
src/snes/tutorials/ex59.c
src/snes/tutorials/ex35.c
src/ts/tutorials/ex30.c
src/ts/tutorials/ex14.c
src/snes/tutorials/ex77.c
src/snes/tutorials/ex5.c
src/snes/tutorials/ex48.c

Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages