(formula) the formula of the basic model that is going
to be fitted. Depending on resptype it will be the formula corresponding
to a coxph model or to a glm model. In the case of "survival" a formula like
Surv(time, status) ~ trt would be expected and in the "binary" case a
formula like y ~ trt.
subgroup_model
(formula) the formula with all the subgroup
variables.
data
(data frame) the data frame with the variables.
resptype
(string) the type of data used. Can be "survival"
or "binary".