New solver method in fenics_mpi_example.py

fenics_mpi_example.py

@@ -6,10 +6,8 @@
 # Runs with fenics 2019.01
 # The resulting .pvd file can be opened using default settings in ParaView
 
-import matplotlib.pyplot as plt
 import mshr as ms
 import numpy as np
-from scipy.optimize import curve_fit
 
 import random
 from dolfin import *
@@ -55,7 +53,7 @@ y_mesh = 1
 # mesh = UnitSquareMesh.create(x_mesh, y_mesh, CellType.Type.quadrilateral)
 # mesh = RectangleMesh(Point(0, 0), Point(1, 0.02), x_mesh, y_mesh)
 domain = ms.Sphere(Point(0, 0, 0), 1.0)
-mesh = ms.generate_mesh(domain, 20)
+mesh = ms.generate_mesh(domain, 60)
 P1 = FiniteElement("Lagrange", mesh.ufl_cell(), 1)
 ME = FunctionSpace(mesh, P1*P1)
 # Define trial and test functions
@@ -87,7 +85,9 @@ a = derivative(L, u, du)
 # Create nonlinear problem and Newton solver
 problem = CahnHilliardEquation(a, L)
 solver = NewtonSolver()
-solver.parameters["linear_solver"] = "lu"
+solver.parameters["linear_solver"] = "gmres"
+solver.parameters["preconditioner"] = "ilu"
+#solver.parameters["linear_solver"] = "mumps"
 solver.parameters["convergence_criterion"] = "incremental"
 solver.parameters["relative_tolerance"] = 1e-6
 # Output file
@@ -95,9 +95,9 @@ file = File("output.pvd", "compressed")
 
 # Step in time
 t = 0.0
-T = 10*dt
+T = 3*dt
 while (t < T):
     file << (u.split()[0], t)
     t += dt
     u0.vector()[:] = u.vector()
-    solver.solve(problem, u.vector())
\ No newline at end of file
+    solver.solve(problem, u.vector())