[R] splineDesign and not-a-knot conditions

[Tamas K Papp]

Hi,

I would like to fit an (interpolating) spline to data where the
derivatives at the endpoints of the interval are nonzero, thus the
natural spline endpoint-specification does not make sense.  Books (de
Boor, etc) suggest that in this case I use not-a-knot splines.

I know what not-a-knot splines are (so if I were solving for the
coefficients directly I knew how to do this), but I don't know how to
sensibly enforce this restriction on the B-spline basis.  I would
appreciate any advice, references or example code.

Thanks,

Tamas