Thank you Andrew. We will look at that closely.
But if we are solving a linear system using LU then we shouldn't be using snes though should we? That is the error we are getting in convergence.
Hello,
We are trying to solve a 2-layer Quasi-Geostrophic model to determine a steady linear solution, basically building on a demo that we already wrote.
When we try running it we get the following error, copied below.
It seems to have a problem with the nonlinear solver, even though we are solving a linear problem. Can anyone give us some advice on how we might be able to fix this?
Code is attached in case you wanted to see the details.
Cheers, Francis
(firedrake) fpoulin@domlt32:~/Dropbox/Research_Keegan/Code$ python test.py Traceback (most recent call last):File "test.py", line 91, in <module>soln0 = steadylinearQG2d(Ztrial, Ztest, Gwinds, bcs)File "test.py", line 46, in steadylinearQG2dlinear_solver.solve()File "/home/fpoulin/software/firedrake/src/firedrake/ firedrake/variational_solver. py", line 223, in solve solving_utils.check_snes_convergence(self.snes) File "/home/fpoulin/software/firedrake/src/firedrake/ firedrake/solving_utils.py", line 233, in check_snes_convergence %s""" % (snes.getIterationNumber(), msg))firedrake.exceptions.ConvergenceError: Nonlinear solve failed to converge after 0 nonlinear iterations. Reason:Inner linear solve failed to converge after 0 iterations with reason: unknown reason (petsc4py enum incomplete?), try with -snes_converged_reason and -ksp_converged_reason
------------------
Francis Poulin
Associate Professor
Department of Applied Mathematics
University of Waterloo
email: fpoulin@uwaterloo.ca
Web: https://uwaterloo.ca/poulin-research-group/
Telephone: +1 519 888 4567 x32637