PyGeo: a dynamic geometry toolkit

u_circles

spheric section of the Riemann sphere

f uCircle() ...

factory function returns instance of a class representing a spheric section of the Riemann sphere

constructors:
uCircle (point )
spheric section of Riemann sphere cut by the plane polar to the given point with respect to Riemann sphere
uCircle (plane )
spheric section of Riemann sphere cut by the plane polar to the given point with respect to Riemann sphere
uCircle (zcircle )
spheric section of the Riemann sphere stereographically projected from the given circle of the complex plane
uCircle (upoint1,upoint2,upoint3 )
spheric section of the Riemann sphere through 3 given points on the sphere
uCircle (point1,point2 )
spheric section of the Riemann sphere cut by the plane at the initial point argument and normal to the direction determined by the given 2 point

See the source for more information.