I was solving Laplace equation in MATLAB numerically. However I have problems when the domain is not rectangular.
The equation is as follows:
$ \frac{\partial^2 u}{\partial x^2}+\frac{\partial^2 u}{\partial y^2}=0 $
domain is circular
$ x^2 + y^2 < 16 $
and boundary condition $ u(x,y)= x^2y^2 $
How should I start with solving this equation numerically ?