PDETOOL - How to find the label of domain?

I am having some problems in the pdetool toolbox (Using Matlab 2017a): My code defines the outer geometry of my system as the domain number 1 for a certain geometry:

However, for a second geometry (similar to the previous), the code labels the outer geometry as a different number (3 in this case).

I need to have different PDE coefficients in the outer domain. Is there a way to know which domain number is the outer rectangle of my system?

Answer 1

[Alan Weiss]

I don't know how to choose the label numbers in a geometry except by creating the geometry using a Geometry Function. See Geometry Function Example with Subdomains and a Hole.

Alan Weiss

MATLAB mathematical toolbox documentation

[Tadeu Fagundes]

Thanks you Mr. Weiss! This was exactly what I needed. I went through the decomposed geometry file and found the labels I needed!