Alex Jones

`dVx` and `dVy` and `S(x, y)` don't look symmetrical, are you sure the result should be?

I don't actually have any drift diffusion examples, I'd like to get this working so it can be added. Corner points are currently dirichlet 0, but they are not used...

@apekshasingh Were you satisfied that this was working in the end?

@a12591771 DiffEqOperators should work if you manually construct the spherical laplacian from the operators and use a `d_theta` defined in terms of `r` for each unit disk

Seems to boil down to this: Yes good go ahead: ```julia eq = Dτ(g(τ, x)) ~ - λ * (x - xb) * Dx(g(τ, x)) ``` No stop bad: ```julia...

>@YingboMa would it be a bad idea to add array symbolic expressions x ~ 0:Δx:ℓ as observed variables so that sol[x] works? @YingboMa is this a bad idea?

Hi, thanks for your interest. Unfortunately this isn't possible at the moment, and likely won't be for some time until we have better integration with ModelingToolkit, since equations aren't marked...

You could create a variable `u_bc` and use it in a bc equation, as long as a boundary i.e. `u(t, 0)` is referenced in the equation it should work. Try...

The following is equivalent, you could build up a larger ODE system by adding your ODEs to `eqs`. Hopefully you will be able to adapt this to your needs ```julia...

Explicit mixed derivatives are unfortunately not yet supported, though may be solved by defining an auxiliary variable like `Dxx_u(t, x) ~ Dxx(u(t,x))` and doing `Dt(Dxx_u(t, x))` instead.