pros/cons of teaching attach()
This thread is interesting. For those who use the subset command, when you extract a variable from a data frame, do you give it the same name as in the data set? For instance, my.data with variables trout, whale trout <- subset(my.data, select=trout, drop=T) I guess if you never attach, then you don't have to worry about masking in the future. Thanks -Laura
On 9/21/2010 11:34 PM, Joshua Wiley wrote:
Hi all, I am wondering if anyone teaches the attach function to new students and if so, why? I have never taught a class using R, but in small tutorials and providing direct help, I have run across this issue several times. I have always avoided it, but a couple of times, students had learned to use it in a class (though without much detail) and were rather grumpy with me for using full variable names or with(). New converts, particularly from GUIs like SPSS, already tend to be leery of R, and I hate to make working at the command line more onerous since any typing is more than they are used to, but at the same time a discussion of environments, which I think is necessary to avoid trouble with attach, does not seem like beginner material either. I have wondered about this many times, but was just reminded again by an R-help post. Thanks, Josh
************************************************ Laura Chihara Professor of Mathematics 507-222-4065 (office) Dept of Mathematics 507-222-4312 (fax) Carleton College 1 North College Street Northfield MN 55057