expand.nested {coxme} | R Documentation |
Expand out the data frame for a nested factor such as (1| a/b).
This is used by the variance function routines of coxme
.
expand.nested(x)
x |
A data frame containing the nesting variables |
The initialize function of a coxme
variance family is
passed, as one of its arguments, a data frame G
containing
the grouping variables, each of which is a factor..
Assume a nested factor (1| a/b)
in the model formula and
a data set whose first few rows are:
a b 1 1 1 2 2 1
The function will replace the second column with a variable named
a/b
and values of 1/1, 1/2, 2/1, etc.
an updated data frame
Terry Therneau