Hello,
I am trying to get the diameter of a circle inscribing all elements of the mesh. The Circumradius(submesh) call works perfectly well to get the diameter of the circumscribed circle to an element. I tried using the nradius and radius_ratio (to get a measure of the inscribed circle) calls, but I got an error stating that these functions could not be found.
Thank you.
Have you tried inradius, as illustrated below:
from dolfin import *
mesh = UnitSquareMesh(3, 5)
x = SpatialCoordinate(mesh)
f = project(as_vector((x[0], 0.2*cos(pi*x[0]))), VectorFunctionSpace(mesh, "CG", 1))
ALE.move(mesh, f)
plot(mesh)
import matplotlib.patches
import matplotlib.pyplot as plt
ax = plt.gca()
for k, cell in enumerate(cells(mesh)):
Ai = [cell.facet_area(i) for i in range(cell.num_entities(cell.dim()-1))]
vertices = [Vertex(mesh, vertex).point().array() for vertex in cell.entities(0)]
in_center = 1/sum(Ai)*sum([Ai[i]*vertices[i] for i in range(len(vertices))])
in_radius = cell.inradius()
print(k, in_center, in_radius)
ax.add_patch(matplotlib.patches.Circle(in_center, radius=in_radius))
plt.savefig("mesh.png")
producing:
and
0 [ 0.58001903 0.21040681 0. ] 0.0866476344147409
1 [ 0.08489818 0.31847627 0. ] 0.08489818020317372
2 [ 1.24720071 0.0073444 0. ] 0.08613262635439059
3 [ 0.75223957 0.1911881 0. ] 0.08557290042011083
4 [ 1.91615492 -0.11556556 0. ] 0.0838450750292337
5 [ 1.42056823 -0.01151569 0. ] 0.08723489936746424
6 [ 0.58040448 0.41071269 0. ] 0.0862621851307255
7 [ 0.08625982 0.51727716 0. ] 0.08625981604861797
8 [ 1.24864511 0.208154 0. ] 0.08468821873196429
9 [ 0.75181641 0.39196253 0. ] 0.08514974030649528
10 [ 1.91379241 0.0824004 0. ] 0.08620758884569725
11 [ 1.41911596 0.18947733 0. ] 0.0857826299462477
12 [ 0.58058316 0.61091072 0. ] 0.08608350852374855
13 [ 0.08618931 0.71752879 0. ] 0.08618931097831321
14 [ 1.24836467 0.40786445 0. ] 0.08496866054101737
15 [ 0.75163533 0.59213555 0. ] 0.08496866054101723
16 [ 1.91381069 0.28247121 0. ] 0.0861893109783131
17 [ 1.41941684 0.38908928 0. ] 0.08608350852374876
18 [ 0.58088404 0.81052267 0. ] 0.08578262994624765
19 [ 0.08620759 0.9175996 0. ] 0.0862075888456972
20 [ 1.24818359 0.60803747 0. ] 0.08514974030649511
21 [ 0.75135489 0.791846 0. ] 0.08468821873196425
22 [ 1.91374018 0.48272284 0. ] 0.08625981604861775
23 [ 1.41959552 0.58928731 0. ] 0.08626218513072578
24 [ 0.57943177 1.01151569 0. ] 0.08723489936746431
25 [ 0.08384508 1.11556556 0. ] 0.08384507502923377
26 [ 1.24776043 0.8088119 0. ] 0.0855729004201108
27 [ 0.75279929 0.9926556 0. ] 0.08613262635439078
28 [ 1.91510182 0.68152373 0. ] 0.08489818020317355
29 [ 1.41998097 0.78959319 0. ] 0.08664763441474055
Thank you. No haven’t tried it. But would I be able to use the in_radius variable in my variational form?
Put the in_radius variable in the appropriate entries of a DG0 space and you can use it in a variational form. Or you could create your own custom UserExpression.
Sounds good, thank you.