Tells if the spline is rational or not.
If it is true (rational), then the NURBS is a piecewise rational polynomial function.
If it is false (non-rational), then the NURBS is a piecewise polynomial function.
Namespace: Autodesk.Revit.DBAssembly: RevitAPI (in RevitAPI.dll) Version: 20.0.0.0 (20.0.0.377)
Since: 2016