Bug in "transform"?
Many thanks for your kind responses.
That's a simple change and will make transform.data.frame behave more consistently with cbind.data.frame and data.frame.
Related to above, I find rather inconsistent following behavior:
aq <- airquality[sample(1:153,6),]
data.frame(aq, list(a=1,b=2))
Error in data.frame(aq, list(a = 1, b = 2)) : arguments imply differing number of rows: 6, 1
cbind(aq,list(a1=1,a2=2))
Error in data.frame(..., check.names = FALSE) :
arguments imply differing number of rows: 6, 1
but,
aq[c("a","b")]<-list(1,2) #works fine
In my understanding all versions above are conceptually similar and should
behave in a same way, and recycling for one row data.frames should be a
default. R is an interactive language and behavior like above is a real
pain.
Just learn to use indexing: transform() is just syntactic sugar that you are not making use of.
I really try to use indexing in code all the time I possibly can. But for interactive use with dozens of data transformations and reshapings per day - with just indexing I would probably see stars at the end of the day. Thanks for existence of such "syntactic sugars" and for packages like Hadley's reshape and plyr. Regards, Vitalie.