Create 2-D geometry from decomposed geometry matrix
Create a decomposed solid geometry model and include it in a PDE model.
Create a default scalar PDE model.
model = createpde;
Define a circle in a rectangle, place these in one matrix, and create a set formula that subtracts the circle from the rectangle.
R1 = [3,4,-1,1,1,-1,0.5,0.5,-0.75,-0.75]'; C1 = [1,0.5,-0.25,0.25]'; C1 = [C1;zeros(length(R1) - length(C1),1)]; gm = [R1,C1]; sf = 'R1-C1';
Create the geometry.
ns = char('R1','C1'); ns = ns'; g = decsg(gm,sf,ns);
Include the geometry in the model and plot it.
geometryFromEdges(model,g); pdegplot(model,'EdgeLabels','on') axis equal xlim([-1.1,1.1])
model— Model object
Model object, specified as a
ThermalModel object, or
model = createpde(1)
thermalmodel = createpde('thermal','steadystate')
structuralmodel = createpde('structural','static-solid')
g— Geometry description
Geometry description, specified as a decomposed geometry matrix, as the
name of a geometry function, or as a handle to a geometry function. For
details about a decomposed geometry matrix, see
A geometry function must return the same result for the same input arguments in every function call. Thus, it must not contain functions and expressions designed to return a variety of results, such as random number generators.