Generate meshes from polar coodinates

Blender has a capability to generate meshes from rectangular equations - Add>Mesh>Math Function>Z Function.

A large class of interesting shapes can be generated from polar coordinate equations.

A new feature would be to add shapes defined from polar coordinates: Add>Mesh>Math Functions>R Function - which would add functions defined in terms of phi and rho. Add?Mesh>Math Functions>R-Rho-Phi