I think your idea to remove the warnings is excellent, and a good compromise. Characters already work fine in modeling functions except for the silly warning.

It is interesting how often the defaults for a program reflect the data sets in use at the time the defaults were chosen. There are some such in my own survival package whose proper value is no longer as "obvious" as it was when I chose them. Factors are very handy for variables which have only a few levels and will be used in modeling. Every character variable of every dataset in "Statistical Models in S", which introduced factors, is of this type so auto-transformation made a lot of sense. The "solder" data set there is one for which Helmert contrasts are proper so guess what the default contrast option was? (I think there are only a few data sets in the world for which Helmert makes sense, however, and R eventually changed the default.)

For character variables that should not be factors such as a street adress stringsAsFactors can be a real PITA, and I expect that people's preference for the option depends almost entirely on how often these arise in their own work. As long as there is an option that can be overridden I'm okay. Yes, I'd prefer FALSE as the default, partly because the current value is a tripwire in the hallway that eventually catches every new user.

Terry Therneau

On 02/11/2013 05:00 AM, r-devel-requ...@r-project.org wrote:
Both of these were discussed by R Core.  I think it's unlikely the
default for stringsAsFactors will be changed (some R Core members like
the current behaviour), but it's fairly likely the show.signif.stars
default will change.  (That's if someone gets around to it:  I
personally don't care about that one.  P-values are commonly used
statistics, and the stars are just a simple graphical display of them.
I find some p-values to be useful, and the display to be harmless.)

I think it's really unlikely the more extreme changes (i.e. dropping
show.signif.stars completely, or dropping p-values) will happen.

Regarding stringsAsFactors:  I'm not going to defend keeping it as is,
I'll let the people who like it defend it.  What I will likely do is
make a few changes so that character vectors are automatically changed
to factors in modelling functions, so that operating with
stringsAsFactors=FALSE doesn't trigger silly warnings.

______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel

Reply via email to