Hey guys,

I'm having problems with the Function.at() function. Below is an example code

from __future__ import division
from firedrake import *
import numpy as np

mesh_base = SquareMesh(8, 8, 1.)
mesh_hierarchy = MeshHierarchy(mesh_base, 6)

fine_msh = mesh_hierarchy[6]       # 512 x 512 mesh
fine_dg_space = FunctionSpace(fine_msh, "DG", 1)

x, y = SpatialCoordinate(fine_dg_space)
q0 = Function(fine_dg_space).interpolate(x)

x_array = np.array([_x / 512.0 for _x in range(513)])  # coordinates
# x_array[0] += 1. / 1000000.0  # a slight nudge away from boundary also fails

for i in x_array:
    for j in x_array:
        print [i, j], q0.at(np.array([i, j]))

My domain is [0, 1], mesh size 512x512. I keep on getting the following PointNotInDomainError when I run the above, where 0.43164062 correspond to 221 of 512. What am I doing wrong?

[0.0, 0.427734375] 0.0
[0.0, 0.4296875] 0.0
[0.0, 0.431640625]
Traceback (most recent call last):
  File "/home/wpan1/PycharmProjects/MyFirstProject/test_at.py", line 22, in <module>
    print [i, j], q0.at(np.array([i, j]))
  File "/home/wpan1/Documents/firedrake/src/firedrake/firedrake/function.py", line 574, in at
    raise PointNotInDomainError(self.function_space().mesh(), points[i].reshape(-1))
firedrake.function.PointNotInDomainError: domain <Mesh #7> does not contain point [ 0.          0.43164062]