Meshing the Omega aka. BERT logo¶

This is a fun example creating a logo for the BERT software. It illustrates the possibility to hand over matplotlib path objects to the TriangleWrapper.

import matplotlib.pyplot as plt
import matplotlib.textpath
import pygimli as pg

We start by generating a matplotlib path respresenting the \(\Omega\) character.

logo_path = matplotlib.textpath.TextPath((0, 0), r'$\Omega$', size=1)
patch = matplotlib.patches.PathPatch(logo_path)

The vertices of the path are defined as mesh nodes and connected with edges.

nodes = patch.get_verts() * 50
nodes = pg.utils.unique_rows(nodes)  # remove duplicate nodes
poly = pg.Mesh(2)

for node in nodes:
    poly.createNode(node[0], node[1], 0.0)

for i in range(poly.nodeCount() - 1):
    poly.createEdge(poly.node(i), poly.node(i + 1))

poly.createEdge(poly.node(poly.nodeCount() - 1), poly.node(0))

We call the TriangleWrapper to generate the mesh and set the x values as the data for a color transition.

tri = pg.TriangleWrapper(poly)
mesh = pg.Mesh(2)
tri.setSwitches('-pzeAfa5q33')
tri.generate(mesh)

data = []
for cell in mesh.cells():
    data.append(cell.center().x())

Last, we create a BERT caption, visualize the mesh and fine-tune the figure.

fig, ax = plt.subplots(figsize=(4, 3))
ax.axis('off')
offset = -10
t = ax.text(1.7, offset, 'BERT', fontsize=37, fontweight='bold')
pg.show(mesh, data, ax=ax, cmap='RdBu', logScale=False, showLater=True)
pg.show(mesh, ax=ax)
ax.set_ylim(offset, mesh.ymax())

pg.wait()