title: number of control points for B spline curve
body: <p>I am trying to use B spline curve fitting. The order of B spline curve is 4. When I have many control points, it works well. However if the number of control points is small such as two, my program will crash. I realize that the number of control points is related to number of knots and the order. Can anyone help me clarify the relationship or give some links on it?</p>