In [1]:

%matplotlib inline

In [2]:

from dolfin import *

In [3]:

# Create mesh and define function space
mesh = UnitSquareMesh(8, 8)
V = FunctionSpace(mesh, "Lagrange", 1)

In [4]:

# Define Dirichlet boundary (x = 0 or x = 1)
def boundary(x):
    return x[0] < DOLFIN_EPS or x[0] > 1.0 - DOLFIN_EPS

In [5]:

from dolfin.common import plotting

In [6]:

# Define boundary condition
u0 = Constant(0.0)
bc = DirichletBC(V, u0, boundary)

In [7]:

# Define variational problem
u = TrialFunction(V)
v = TestFunction(V)
f = Expression("10*exp(-(pow(x[0] - 0.5, 2) + pow(x[1] - 0.5, 2)) / 0.02)", degree=2)
g = Expression("sin(5*x[0])", degree=2)
a = inner(grad(u), grad(v))*dx
L = f*v*dx + g*v*ds

In [8]:

# Compute solution
w = Function(V)
solve(a == L, w, bc)

In [9]:

import matplotlib.pyplot as plt
fig = plt.figure()
plot(w)

Out[9]:

<matplotlib.tri.tricontour.TriContourSet at 0x7f01a9649780>

In [10]:

_.collections

Out[10]:

<a list of 35 mcoll.PathCollection objects>

In [11]:

from matplotlib import animation

def animate(i):
    print("frame %i" % i)
    f = Expression(f"10*exp(-(pow(x[0] - 0.05 * {i}, 2) + pow(x[1] - 0.5, 2)) / 0.02)", degree=2)
    L = f*v*dx + g*v*ds
    # Compute solution
    u = Function(V)
    solve(a == L, u, bc)
    plt.title("x-%.2f" % (.05 * i))
    return plot(u).collections

In [12]:

# construct the animation
fig = plt.gcf()
anim = animation.FuncAnimation(fig, animate,
                               frames=20, interval=50)

# generate the HTML animation
anim.save("anim.html", writer="html")
plt.close(fig)

# display the resulting HTML
from IPython.display import HTML, display
with open("anim.html") as f:
    display(HTML(f.read()))

frame 0
frame 0
frame 1
frame 2
frame 3
frame 4
frame 5
frame 6
frame 7
frame 8
frame 9
frame 10
frame 11
frame 12
frame 13
frame 14
frame 15
frame 16
frame 17
frame 18
frame 19