polyshapeThis example shows how to create a polygonal geometry using the MATLAB polyshape function. Then use the triangulated representation of the geometry as an input mesh for the geometryFromMesh function.
Create and plot a polyshape object of a square with a hole.
t = pi/12:pi/12:2*pi;
pgon = polyshape({[-0.5 -0.5 0.5 0.5], 0.25*cos(t)}, ...
{[0.5 -0.5 -0.5 0.5], 0.25*sin(t)})pgon =
polyshape with properties:
Vertices: [29x2 double]
NumRegions: 1
NumHoles: 1
plot(pgon)
axis equal
Create a triangulation representation of this object.
tr = triangulation(pgon);
Create a PDE model.
model = createpde;
With the triangulation data as a mesh, use the geometryFromMesh function to create a geometry. Plot the geometry.
tnodes = tr.Points'; telements = tr.ConnectivityList'; geometryFromMesh(model,tnodes,telements); pdegplot(model)

Plot the mesh.
figure pdemesh(model)

Because the triangulation data resulted in a low-quality mesh, generate a new finer mesh for further analysis.
generateMesh(model)
ans =
FEMesh with properties:
Nodes: [2x1259 double]
Elements: [6x579 double]
MaxElementSize: 0.0566
MinElementSize: 0.0283
MeshGradation: 1.5000
GeometricOrder: 'quadratic'
Plot the mesh.
figure pdemesh(model)
