Glacier Recent mention of various curves used by CAD programs leads me to ask what would be the correct curve to use say to plot an Alenema with modest iterations of the co-ordinates. Various CAD and drawing programs offer Bezier, Parametric,Cubic and Parabolic Spline or S Polyline, Quadratic and NURBS. Each curve seems to either follow the nodes exactly as in parabolic or take various approximations with the more sophisticated CAD programs allowing a system variable to set the sensitivity. Obviously the more
