slope {frailtypack} | R Documentation |
Identify variable associated with the random slope
Description
This is a special function used in the context of survival additive models.
It identifies the variable which is in interaction with the random slope
(). Generally, this variable is the treatment variable.
Using
interaction()
in a formula implies that an additive frailty
model is fitted.
Usage
slope(x)
Arguments
x |
A factor, a character or a numerical variable |
Value
x |
The variable in interaction with the random slope |
Note
It is necessary to specify which variable is in interaction with the random slope, even if only one explanatory variable is included in the model.
See Also
Examples
data(dataAdditive)
##-- Additive with one covariate --##
modAdd1cov <- additivePenal(Surv(t1,t2,event)~cluster(group)+var1+
slope(var1),data=dataAdditive,n.knots=8,kappa=10000,hazard="Splines")
##-- Additive with two covariates --##
set.seed(1234)
dataAdditive$var2 <- rbinom(nrow(dataAdditive),1,0.5)
modAdd2cov <- additivePenal(Surv(t1,t2,event)~cluster(group)+var1+
var2+slope(var1),data=dataAdditive,n.knots=8,kappa=10000,
hazard="Splines")
##-- Additive with 2 covariates and stratification --##
dataAdditive$var2 <- rbinom(nrow(dataAdditive),1,0.5)
modAddstrat <- additivePenal(Surv(t1,t2,event)~cluster(group)+
strata(var2)+var1+slope(var1),data=dataAdditive,n.knots=8,
kappa=c(10000,10000),hazard="Splines")
[Package frailtypack version 3.6.2 Index]