Divergence of vector in 2D

Comparing the quiver plot of the vector function to the surface plot of its divergence scalar function

Live Script showing an example of a vector valued function w in 2D space (x and y) evaluated as a quiver plot. The divergence of w is a scalar field with values: negative, zero, and positive corresponding to net w flow: sinks (draining), even (conservation), and sources (originating), respectively.