Add option to integrate filter to divide by volume
My user wants to add a feature to the integrate filter that allows not just the sum of the items, but sum or integral divided by the total volume.
From my user:
Can we get a version that provides the average of the quantity? That is, currently if you look at variable
f(x)(x \in 3D), we are getting
\int_D f(x) dx-- an integral of f over the domain
D. However, we often want the average of f over the domain,
(\int_D f(x) dx) / (\int_D dx). Setting up a new variable to scale by the volume for every variable and every plot is annoying...