If both the levels of the starting age factor and the initial.ages vector contain the missing age, then you won’t get any error messages, but the ages after that will be assigned incorrectly. For example, if age 1 is missing, then age 0 will be assigned age 0, age 2 will be assigned age 1, age 3 will be assigned age 2, etc.
If both the levels of the starting age factor and the initial.ages vector skip the missing age(s), then there seem to be no problems. Here is one way to make sure this is the case:
- Code: Select all
bootData1$StartAge=as.factor(as.integer(bootData1$StartAge))
init.ages=as.integer(levels(bootData1$StartAge))
kit.boot.process = process.data(bootData1, model="Burnham", groups=c("Sex", "StartAge"), age.var=2, initial.ages=init.ages)
Hope this helps someone,
Jeff