Update icosahedron.py

Author: tkoyama010

examples/icosahedron.py

@@ -1,4 +1,12 @@
-"""scikit-gmsh package for 3D mesh generation test."""
+r"""
+Icosahedron geometry example
+----------------------------
+
+Icosahedron geometry example.
+
+"""
+
+# sphinx_gallery_thumbnail_number = 2 # noqa:ERA001
 
 from __future__ import annotations
 
@@ -9,5 +17,9 @@
 edge_source = pv.Icosahedron()
 edge_source.merge(pv.PolyData(edge_source.points), merge_points=True, inplace=True)
 edge_source.plot(show_edges=True)
+
+# %%
+# Generate the mesh.
+
 delaunay_3d = sg.Delaunay3D(edge_source)
 delaunay_3d.mesh.shrink(0.9).plot(show_edges=True)