KDL::Path_Circle constructor

Hello,
could someone please explain clearly the use of each of the
KDL::Path_Circle constructor parameters?

KDL::Path_Circle::Path_Circle
<http://docs.ros.org/hydro/api/orocos_kdl/html/classKDL_1_1Path__Circle.html#a2ea743324c49ce71ce07b8add71590ca>
(const Frame
<http://docs.ros.org/hydro/api/orocos_kdl/html/classKDL_1_1Frame.html> &
F_base_start,const Vector
<http://docs.ros.org/hydro/api/orocos_kdl/html/classKDL_1_1Vector.html> &
V_base_center,const Vector
<http://docs.ros.org/hydro/api/orocos_kdl/html/classKDL_1_1Vector.html> &
V_base_p,const Rotation
<http://docs.ros.org/hydro/api/orocos_kdl/html/classKDL_1_1Rotation.html> &
R_base_end,double alpha,RotationalInterpolation
<http://docs.ros.org/hydro/api/orocos_kdl/html/classKDL_1_1RotationalInterpolation.html>
* otraj,double eqradius,bool _aggregate = true

Thanks in advance,
Enrico Corvaglia)