I am trying to solve a PDE within a rectangular region with the Matlab PDE toolbox. I am facing two problems:
(1) As shown in the example, I can solve the PDE with the commands:
R = solvepde(model);
u = R.NodalSolution;
However, I want the solution to be evaluated at the regular grid points, not at the nodes. How can I get the value of u at specific (x,y) points?
(2) I would also like to evaluate the spatial differentiation of the solution u, that is, I want to calculate du/dx and du/dy at the regular grid points. I can do it numerically, but I just want to do all the things directly from Matlab. Is there any command that can help me?
Thank you very much.