Actually, I’m trying to solve the equation in the from of “(B-rC)w=Bv” based on the ‘cg’ iteration method with the preconditioner ‘ilu’. In the equation, B is a 307724 * 307724 PETScMatrix, and the corresponding code is:
import dolfin as df
D = df.PETScMatrix(B.mat() - C.mat() * r[j])
solver = df.PETScKrylovSolver("cg", "ilu")
solver.parameters["absolute_tolerance"] = 1e-17
solver.parameters["maximum_iterations"] = 10000
After running the code, it reminded me an error shown in the figure.
So I’m thinking whether there is some parameters are set incorrectly or some other parameters like ‘Relaxation factor’ are missed to be set. So I wonder to know all Solver.parameters that should be set in such occasion.
Thanks ahead!