There are a zillion resources on splines, but I can't seem to find this.
I need an algorithm for a smoothing (cubic) spline where the endpoint derivatives are specified (the so-called 'clamped spline').
With no smoothing (so just ordinary interpolation), there are many treatments.
With so-called 'natural' endpoints (second derivative is zero) + smoothing, there are many treatments.
Trying to not reinvent the wheel.
Does anyone know a link or a cite?