How to get the spacial poisiton
 

Is there an easy way to get the spacial position of a node?

For example, on a 2D mesh that's 1m x 1m, I need to multiply a diffusivity by its distance between the current location on the mesh and from the origin (ie. x=0,y=0,z=0).

So I need something like:

I'm not sure how to get the distance_x[i] and distance_y[i] parts.