design.matrix {survPen}

Design matrix for the model needed in Gauss-Legendre quadrature

Description

Builds the design matrix for the whole model when the sum-to-zero constraints are specified. The function is called inside model.cons for Gauss-Legendre quadrature.

Usage

design.matrix(
  formula,
  data.spec,
  t1.name,
  Z.smf,
  Z.tensor,
  Z.tint,
  list.smf,
  list.tensor,
  list.tint,
  list.rd
)

Arguments

formula

formula object identifying the model

data.spec

data frame that represents the environment from which the covariate values and knots are to be calculated

t1.name

name of the vector of follow-up times

Z.smf

List of matrices that represents the sum-to-zero constraint to apply for smf splines

Z.tensor

List of matrices that represents the sum-to-zero constraint to apply for tensor splines

Z.tint

List of matrices that represents the sum-to-zero constraint to apply for tint splines

list.smf

List of all smf.smooth.spec objects contained in the model

list.tensor

List of all tensor.smooth.spec objects contained in the model

list.tint

List of all tint.smooth.spec objects contained in the model

list.rd

List of all rd.smooth.spec objects contained in the model

Value

design matrix for the model

Examples

library(survPen)

# standard spline of time with 4 knots

data <- data.frame(time=seq(0,5,length=100),event=1,t0=0)

form <- ~ smf(time,knots=c(0,1,3,5))

t1 <- eval(substitute(time), data)
t0 <- eval(substitute(t0), data)
event <- eval(substitute(event), data)
	
# Setting up the model
model.c <- model.cons(form,lambda=0,data.spec=data,t1=t1,t1.name="time",
t0=rep(0,100),t0.name="t0",event=event,event.name="event",
expected=NULL,expected.name=NULL,type="overall",n.legendre=20,
cl="survPen(form,data,t1=time,event=event)",beta.ini=NULL)
 
# Retrieving the sum-to-zero constraint matrices and the list of knots
Z.smf <- model.c$Z.smf ; list.smf <- model.c$list.smf

# Calculating the design matrix
design.M <- design.matrix(form,data.spec=data,t1.name="time",Z.smf=Z.smf,list.smf=list.smf,
Z.tensor=NULL,Z.tint=NULL,list.tensor=NULL,list.tint=NULL,list.rd=NULL)