Hey AD, I had a look through your code and found that the functions that you have been using currently has no MATLAB documentation and would have previously belonged to R2022b, not to the one I am using R2023a. However here a demo code I can provide to get you started on PDE.
% Define the PDE problem
% Step 1: Define the PDE coefficients, boundary conditions, and initial conditions
% Create a PDE model
model = createpde();
% Step 2: Specify the geometry
% Use either geometryFromEdges or geometryFromMesh to define the geometry
% Step 3: Specify the boundary conditions
% Use applyBoundaryCondition to specify the boundary conditions
% Step 4: Specify the PDE coefficients and source term
% Use specifyCoefficients to specify the PDE coefficients and source term
% Step 5: Solve the PDE
result = solvepde(model);
% Step 6: Extract and analyze the solution
% Extract the solution using the result.Mesh and result.NodalSolution properties
% Analyze the solution as needed (e.g., plot, compute derived quantities)
% Example: Plot the solution
pdeplot(model, 'XYData', result.NodalSolution);
You may need to refer to the PDE Toolbox documentation and examples for more detailed information and specific usage of functions mentioned above.