Cubic Spline Derivative

Community Forums/General Help/Cubic Spline Derivative

beanage (Posted 2010) [#1]

Hey, I just came across this problem, and cant really get my head around it. It just exceeds my high-school maths skills :{ What I essentially want to do, is calculating the distance of a point to a spline curve. Naturally, to retrieve the spline interpolation value closest to the point, what I did was creating this equation, which I would solve for s: Anybody a clue of how to retreive Spline' ?

Sauer (Posted 2010) [#2]

Well, Spline is a function, which you should know when defining the spline. Spline' will be the derivative of Spline at point s.

Floyd (Posted 2010) [#3]

There won't be any easy answer to this. It will come down to some kind of numerical approximation. You could start your research here: http://www.google.com/search?hl=en&source=hp&q=%22cubic+spline%22+closest+point

beanage (Posted 2010) [#4]

@Floyd: I must apologize for having been a little upset about your answer :) To my defence, up to this very point in time, there has never been a problem I couldnt find an analytical solution for.. yay, until now. Took my a while to dig through the various approximation methods. A good resource was this PDF. My final solution can be found in the Code Archives.