Extended knot sequence for degree > 1

[matthiaskaeding]

Hi,

there is something I do not understand about splines2::bSpline, I tried to get it from the code but couldn`t find it:

If one sets the degree to a value >= 1, additional knots are required. How are they chosen, and is it possible to adjust those?

Cheers
Matthias

[wenjie2wang]

Hi,

If one sets the degree to a value >= 1, additional knots are required. How are they chosen, and is it possible to adjust those?

Do you mean the additional knots placed at the boundary? A simple knot sequence is used internally, where each boundary knot is repeated k+1 times, k represents the degree.

An extended knot sequence can be specified via the Rcpp interface. Or you may want to use splines::splineDesign() instead.

[matthiaskaeding]

Thank, yes I meant the additional knots at the boundary. I think I will use the Rcpp interface then.