PyGeo: a dynamic geometry toolkit

sliders

point which can be picked and moved, with movement constrained to a given geometric object

f Slider() ...

factory function returns instance of a classs object representing a point in space which can be interactively picked, with movement constrained to a given geometric object

constructors:
Slider (circle <,angle=numeric> )
point which can be picked and moved, with movement constrained to given circle
Slider (line <ratio=numeric> )
point that can be picked and moved, with movement constrained to given line
Slider (sphere <,theta=numeric><,phi=numeric> )
point which can be picked and moved, with movement constrained to given sphere
Slider (plane <,[numeric,numeric,numeric]> )
point which can be picked and moved, with movement constrained to given plane

See the source for more information.