[R] aov and non-categorical variables

[Alexander Sirotkin [at Yahoo]]

It is unclear to me how aov() handles non-categorical
variables.

I mean it works and produces results that I would
expect, but I was under impression that ANOVA is only
defined for categorical variables.

In addition, help(aov) says that it "call to 'lm' for
each  stratum", which  I presume means that it calls
to lm() for every group of the categorical variable,
however I don't quite understand what this means for
non-categorical variable.

Thanks