The LR.inter.cat.surv function performs a
likelihood ratio test (LRT) for an interaction term
between a categorical variable and a SNP (coded 0,1,2) in
a cox model. The function returns the p-value of the
likelihood ratio test.
Usage
LR.inter.cat.surv(x, formula, data, Z1)
Arguments
x
name or numeric vector corresponding to the SNP
tested.
formula
an object of class "formula" : a symbolic
description of the model to be fitted without the
interaction term.
data
a data frame containing the variables in the
model.
Z1
name of the variable which is tested in
interaction with x (x:Z1).
Value
p-value of the likelihood ratio test for the interaction
term.
providing 
.