prDescGetAndValidateDefaultRef: A helper function for the description stats
Description
A helper function for the description stats
Usage
prDescGetAndValidateDefaultRef(x, default_ref)
Arguments
x
The variable of interest with the levels
default_ref
The default reference, either first,
the level name or a number within the levels. If left out
it defaults to the first value.
Value
integer
The level number of interest