pros/cons of teaching attach()
On 09/22/2010 04:36 AM, Gavin Simpson wrote:
I don't use attach() at all; too easy to make mistakes that are difficult to track down. I tend not to use $ either as that encourages people to use it to go fiddling in the bowels of other lists (objects); model$residuals might be OK for lm() models (though not if you've used na.exclude for example) but students might be surprised with what they get with more complex modelling functions with different residuals.
This is going to be a dumb question, but what do you use instead of $ for accessing variables in a list? [[]] allows for the same fiddling. Thanks, Tyler