Reaction Diffusion in 3D
I am trying to solve a reaction diffusion equation at steady state. This solution generally becomes the Poisson equation. Normally, f can be a function of the spatial variables f(x,y,z). In my specific case this represents the reaction term in my reaction diffusion equation. How can I specify a f that varies with space? I have tried creating a data object with a rank of three to hold all of these values, however this gives me an error saying that the "Expected shape of coefficient is () but actual shape is (25L, 25L, 25L)". Am I just defining my data-set incorrectly?