Stereographic projection flat mathematical functions 1

High res version created locally with openscad and this script: http://jsfiddle.net/threonin/3j2c2pwe/
functions in polar coordinates:
f(x) =x/20+sin(x?50)/15
g(x) =?x/20+sin(x?50)/15
It's a little streched out as the x-axis was wider than the y-axis in the plotter window.