Exercise 28. Flexible parametric survival models in R

library(biostat3)  
library(rstpm2)  # for the flexible parametric model
library(dplyr)   # for data manipulation
data(melanoma)

## Extract subset and create 0/1 outcome variables
melanoma0 <- melanoma %>% filter(stage=="Localised") %>%
             mutate(event = ifelse(status=="Dead: cancer" & surv_mm<120, 1, 0),
                    time = pmin(120, surv_mm)/12,
                    agegrp1 = (agegrp=="0-44")+0,  # used by time-dependent effect
                    agegrp2 = (agegrp=="45-59")+0, # used by time-dependent effect
                    agegrp3 = (agegrp=="60-74")+0, # used by time-dependent effect
                    agegrp4 = (agegrp=="75+")+0)   # used by time-dependent effect

(a)