This might be an easy question but I am a bit stuck on it. The function gradient yields xy gradients of a 2D field:
But how do I move the other way? I.e.: z=f(px,py) where I have px and py and f is the unknown function/mechanism. My first thought revolves around using filter2 but I can't seem to figure it out.
Secondly: What would be an easy way to determine whether a region is subject to convergence/divergence?