Gradient along an arbitrary selection.

[QuinB]

After an uncomfortable time with Inkscape's Mesh Gradient, I've come up with a 'this is the sort of thing I mean' image
   

It's neither quick nor accurate to the spec., but it gives an idea. Firstly, it's not a Gimp solution, secondly it's a 'by eye' technique that takes a fair bit of manipulation to implement. 

I'll be happy to check out your scripts: they're always an education – thanks.

Q