Blender Analytical Geometry - BAG 0.0.1
With this script you can write in any curve as parametric
(x(u),y(u),z(u)) function or any surface as (x(u,v),y(u,v),z(u,v))
and draw it!
It is not limited to cartesian coords
Here is script -> http://www.selleri.org/Blender/scripts/BAG-0.0.1.zip
Here is demo image (with formula) -> http://www.selleri.org/Blender/buffer/bag1.png
No syntax checking (yet) if formula is wrong script crashes
No save/load functions (yet) this will be fixed in next release, which will also hold some demo functions.