eliminate = NULL in gnm

[goranbrostrom]

Calling gnm with 'eliminate = NULL' leads to failure despite the fact that NULL is the default value of eliminate. The reason is the code snippet

if (!missing(eliminate)) {
eliminate <- modelData$(eliminate)
if (!is.factor(eliminate))
stop("'eliminate' must be a factor")

Wouldn't it be better to replace the first line with 'if (!is.null(eliminate))'?

[hturner]

Thanks for the report. The fix was slightly more complicated as eliminate is usually specified symbolically and then evaluated as if it were a term in the formula. However, I've just committed an update to the master branch that should work with eliminate = NULL.