Ispline {ICsurv}

Ispline

Description

Generates the I-spline basis matrix associated with integrated spline basis functions. Created by Cai and Wang in October, 2009.

Usage

Ispline(x, order, knots)

Arguments

x

the predictor variables.

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

Wang, L., McMahan, C., and Hudgens, M. (2014+). A flexible and computationally efficient method for fitting the proportional hazards model to interval censored data. Submitted.

Ramsay, J. (1988). Monotone regression splines in action. Statistical Science 3, 425-441.