Current density for conductive media DC problem (2d)

I've solved a multi-domain 2D conductive media DC problem for the potential u. I can plot the electric field E ... it's the gradient of the potential. Now I want to plot the current density, J. This is sigma*E where sigma is the conductivity in a region. But I can't figure out how to access what region a point (x,y) is in. Its clearly possible because the solver can do it, but the solver's methods are private.

How do I find the region that a specified point (x,y) is in? Or, is there a function that will plot J (vector field) directly from the solved model?

Thanks.

[Ollie A]

Still looking for an answer? If so then evaluateCGradient will return you the current density for you model at the requested points.