cb {cuRe} | R Documentation |
Restricted cubic splines
Description
Function for computing the basis matrix for restricted cubic splines
Usage
cb(x, df = NULL, knots = NULL, ortho = FALSE, R.inv = NULL, intercept = FALSE)
Arguments
x |
Values to evaluate the basis functions in. |
df |
Degrees of freedom. One can supply |
knots |
Chosen knots for the spline. |
ortho |
Logical. If |
R.inv |
Matrix or vector containing the values of the R matrix from the QR decomposition of the basis matrix.
This is used for making new predictions based on the initial orthogonalization.
Therefore the default is |
intercept |
Logical. If |
Value
A matrix with containing the basis functions evaluated in x
.
References
Royston P. and Parmar M.K. (2002) Flexible parametric proportional-hazards and proportional-odds models for censored survival data, with application to prognostic modelling and estimation of treatment effects. Statistics in Medicine, 21:15.