length fails in aggregate function

[leecreighton]

This is from some R code that worked at one time, and I can't figure what changed.

I want to use the aggregate() function to find the mean, sd, and length of the columns in the PlantGrowth data table.

library("datasets")
data("PlantGrowth")
aggregate(weight ~ group, data = PlantGrowth, mean)
aggregate(weight ~ group, data = PlantGrowth, sd)
aggregate(weight ~ group, data = PlantGrowth, length)

The first two work, producing the mean and standard deviation. The last one doesn't, giving me the error

Error in get(as.character(FUN), mode = "function", envir = envir) : 
  object 'FUN' of mode 'function' was not found

As far as I know, you can find the lengths (which is the number of observations, 10) using this method...or at least can't figure out why you can't.

[leecreighton]

Glad to know it works, although still not on my system. I have not used length in any way in other places of my script, although I’ve done a day’s worth of computing in this R session.

[mattwarkentin]

Maybe try calling the length function directly with ::

aggregate(weight ~ group, data = PlantGrowth, base::length)