[petsc-users] Setting a custom predictor in the generalized-alpha time stepper

[David Kamensky]

Hi,

My understanding is that the second-order generalized-alpha time stepper in
PETSc uses a same-displacement predictor as the initial guess for the
nonlinear solver that executes in each time step.  I'd like to be able to
set this to something else, to improve convergence.  However, my
(possibly-naive) attempts to use `TSSetPreStep` and `TSSetPreStage` haven't
worked out.  Is there any way to set a custom predictor?

Thanks,
David Kamensky