Alec Hammond

It looks like in addition to changing `Expression` to `UserExpression`, you need to initialize the superclass. The child class definition should look like this: ```python class Permeability(UserExpression): def __init__(self, markers,...

> but @profview works and should be able to catch dynamic dispatching. Yup, you're right. Unfortunately, `@profview` doesn't give very much detail regarding where in your code you are dispatching...

Great! Thanks, @albert-de-montserrat! It looks like the current strategy then is to "bootstrap" yourself through the loading process (which I guess is how `ParallelStencil.jl` itself works...) I wonder if there's...

> I would love to be able to also easily get the group index. That would however require multiple frequency points to do a finite difference differentiation on the effective...

> you are talking about this formula, right? Yep that's right. There's lots of ways you can massage it into various forms depending on what the problem looks like and...

@oskooi we might want to look into implementing this as it could save quite a bit of time (by eliminating adjoint solves during the inner iterations).

I'm seeing the same behavior. @stevengj any thoughts on this? I'll try and provide a MWE that quickly reproduces the issue.

Quick drive-by comment (haven't spent too much time digging through this) > Also, just to clarify on the fork approach, I only need to change the for loop on line...

Ya let's close for now, and I can revive it when needed.

Note that there are two ways to discretize the lens (and coating): 1. (the current way) which has uniform steps in the R direction 2. an alternative way involving uniform...