name scoping within dataframe index
On 1/26/2009 1:46 PM, Alexy Khrabrov wrote:
Every time I have to prefix a dataframe column inside the indexing brackets with the dataframe name, e.g. df[df$colname==value,] -- I am wondering, why isn't there an R scoping rule that search starts with the dataframe names, as if we'd said with(df, df[colname==value,]) -- wouldn't that be a reasonable default to prepend to the name search path?
If you did that, it would be quite difficult to get at a "colname"
variable that *isn't* the column of df. It would be something like
df[get("colname", parent.frame()) == value,]
So just use subset(), or with(), or type the extra 3 chars.
Duncan