Returns the value of RadiusOfCurvature attribute. Radius of curvature is radius of parabola or arc. Positive values imply a CCW direction whereas negative CW.

Returns the value of RadiusOfCurvature attribute.

• For PredefinedType is ARC: the radius of the basis circle for the arc.
• For PredefinedType is PARABOLICARC: the parabola constant (determining the “steepness” of the parabola) is provided by the “minimum parabola radius”, the true radius of a parabola is at its vertical axis (the zero-gradient point of the parabola). The minimum radius is twice the focal length of the parabola (the distance between the focal point and the vertex).
• For PredefinedType that is not either ARC or PARABOLICARC: the value should be empty.