Generates the I-spline basis matrix associated with integrated spline basis functions. Created by Cai and Wang in October, 2009. Details can be found in Ramsay (1988).
Usage
Ispline(x, order, knots)
Arguments
x
a vector of observations.
order
the order of the basis functions.
knots
a sequence of increasing points specifying the placement of the knots.
Value
An I-spline basis matrix of dimension c(length(knots)+order-2, length(x)).
References
Ramsay, J. (1988). Monotone regression splines in action. Statistical Science 3, 425-441.