r functions calling lm with subsets

Question

I was working on some code and I noticed something peculiar. When I run LM on a subset of some panel data I have it works fine, something like this:

library(         


        

Answer 1

The problem doesn't seem to be with the subset. I get the same error from your function when I change to subset = (state == 1). The arguments to your function aren't being passed and evaluated correctly.

I think you'd be better off using do.call

myfunction <- function(formula, data, subset) {
    do.call("lm", as.list(match.call()[-1]))
}

myfunction(log(price) ~ log(pop) + log(ndi), Cigar, state == 1)    
# Call:
# lm(formula = log(price) ~ log(pop) + log(ndi), data = Cigar, 
#     subset = state == 1)
#
# Coefficients:
# (Intercept)     log(pop)     log(ndi)  
#    -26.4919       3.2749       0.4265