#! /usr/bin/env python
from matplotlib import pyplot as plt
from fe_utils import ReferenceTriangle, UnitSquareMesh, \
ReferenceInterval, UnitIntervalMesh
from argparse import ArgumentParser
import numpy as np
[docs]def plot_mesh():
parser = ArgumentParser(
description="""Plot the topological entities in a regular mesh."""
)
parser.add_argument("dimension", type=int, nargs=1, choices=(1, 2),
help="Dimension of the domain.")
parser.add_argument(
"resolution", type=int, nargs=1,
help="The number of cells in each direction of the mesh."
)
args = parser.parse_args()
resolution = args.resolution[0]
cell = (None, ReferenceInterval, ReferenceTriangle)[args.dimension[0]]
if cell is ReferenceTriangle:
mesh = UnitSquareMesh(resolution, resolution)
else:
mesh = UnitIntervalMesh(resolution)
fig = plt.figure()
ax = fig.add_subplot(111)
if cell is ReferenceTriangle:
for e in mesh.edge_vertices:
plt.plot(mesh.vertex_coords[e, 0], mesh.vertex_coords[e, 1], 'k')
else:
for e in mesh.adjacency(1, 0):
plt.plot(
mesh.vertex_coords[e, 0], 0. * mesh.vertex_coords[e, 0], 'k'
)
colours = ["black", "red", "blue"]
for i, x in enumerate(mesh.vertex_coords):
x_ = x if cell.dim == 2 else (x[0], 0.)
ax.annotate('(%s, %s)' % (0, i), xy=x_, xytext=(10, 1),
textcoords='offset points', color=colours[0])
for d in range(1, mesh.dim + 1):
adj = mesh.adjacency(d, 0)
for i, e in enumerate(adj):
x = np.mean(mesh.vertex_coords[e, :], axis=0)
x_ = x if cell.dim == 2 else (x[0], 0.)
ax.annotate('(%s, %s)' % (d, i), xy=x_, xytext=(10, 1),
textcoords='offset points', color=colours[d])
if cell is ReferenceTriangle:
ax.axis(np.add(ax.axis(), [-.1, .1, -.1, .1]))
else:
plt.plot(mesh.vertex_coords[:, 0], 0 * mesh.vertex_coords[:, 0], 'ko')
ax.axis([-.1, 1.1, -.1, .1])
plt.show()
