x-coordinates at which to evaluate the spline basis functions
ord
order of the spline. The order is the number of coefficients in each
polynomial segment so a cubic spline has order 4 (the default).
derivs
order of derivative to evaluate at each of the points. If this vector
is given it must have the same length as
x. The default is a vector of
zeros the same length as
x.
VALUE:
a structure with components
knots
knot vector
order
order of the spline
derivs
vector of derivatives.
design
design matrix for the b-splines determined by the knot vector at the
given
x-values. If
derivs has non-zero components, the indicated
derivatives are evaluated instead.