[R] summaryBy: transformed variable on RHS of formula?

[Alexander Shenkin]

Hi Folks,

I'm trying to cut my data inside the summaryBy function.  Perhaps
formulas don't work that way?  I'd like to avoid adding another column
if possible, but if I have to, I have to.  Any ideas?

Thanks,
Allie

    require(doBy)
    df = dataframe(a <- rnorm(100), b <-rnorm(100))
    summaryBy(a ~ cut(b,c(-100,-1,1,100)), data=df) # preferred
solution, but it throws an error
                                                    # Error in
`[.data.frame`(data, , rh.var, drop = FALSE) : undefined columns selected

    df$c = cut(b,c(-100,-1,1,100))
    summaryBy(a ~ c, data=df)       # works fine