What is a good way to create a matrix of index variables based on all
possible combinations of a list of factors in a data-frame, say list(age, sex)? "age"
and "sex" are numeric and factor variables in a dataframe, with 99 and 2
values, respectively.
I would like to use these for subsetting the data-frame, apply functions to
subset and collecting the results.
[[alternative HTML version deleted]]
______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
