I want to solve the diffusion equations:
Thus, in my case m, a, and f are zero. If we are in Cartesian coordinate then d is one and c, the diffusion constant, is for example 0.001. However, I want to solve the equations in spherical coordinates. Here is a link to Laplacian in spherical coordinate:
How can I solve the diffusion equation in the spherical coordinates in Matlab? or How can I determine the matrix of coefficienct "c" in spherical coordinates?