Hey everyone! Thank you very much for helping me last time. I really appreciate them.

Right now I have a question. Maybe it is kind of basic but I really want to figure it out. I am converting some of my fenics code in fenicsx. However, I noticed all fenicsx demo use pyvista to plot instead of matplotlib. Since I am solving a 1D problem, matplotlib is enough for me to use. However, it seems that the situation is different in the new version of dolfin. In old fenics. I just write

plot(uh)
plt.show()

and I can get a nice plot from matplotlib. However, with dolfinx, I get an error. The code is

from dolfinx import plot
plot(uh) # uh is the solution, which is uh = problem.solve()
plt.show()

and the error is

Traceback (most recent call last):
File "/home/henryyuan/PycharmProjects/Fenicsx simulation/main.py", line 38, in <module>
plot(uh)
TypeError: 'module' object is not callable

So how can I use matplotlib to plot in this situation? Any help and advice would be appreciated.

We do not have integrated supported for matplotlib, as it is severely limited in plotting unstructured meshes. However, as you are using a 1D mesh, you could simply call

import dolfinx
import numpy as np
from mpi4py import MPI
mesh = dolfinx.mesh.create_unit_interval(MPI.COMM_WORLD, 15)
P = 3
V = dolfinx.fem.FunctionSpace(mesh, ("Lagrange", P))
uh = dolfinx.fem.Function(V)
uh.interpolate(lambda x: np.sin(2*np.pi*x[0]))
x = V.tabulate_dof_coordinates()
x_order = np.argsort(x[:,0])
import matplotlib.pyplot as plt
plt.plot(x[x_order, 0], uh.x.array[x_order])
plt.savefig("u_1d.png")