massmatics, You are trying to take the mean/sd of an entire data.frame and therefore you receive an error. You must do some form of subset and take the mean of the 'breaks' column. This can be done a few ways (as with almost anything in R).
AM.warpbreaks2 <- subset(AM.warpbreaks, breaks <= 30) mean(AM.warpbreaks2$breaks) or mean(AM.warpbreaks$breaks[Am.warpbreaks$breaks <= 30]) or more concisely with(AM.warpbreaks, mean(breaks[breaks <= 30])) Again, the main point here is that you need to specify the column when working with a data.frame object. Regards, Charles On Fri, Sep 11, 2015 at 11:02 AM, Tom Wright <t...@maladmin.com> wrote: > On Fri, 2015-09-11 at 07:48 -0700, massmatics wrote: > > AM.warpbreaks<=30 > > The above command is not returning what you expected, what part of the > AM.warpbreaks dataframe is expected to be <= 30? > > Effectively you are using a two stage process. > 1) Create a logical vector identifying rows in the dataframe with a > breaks value <= 30 > 2) use the vector in 1. to extract just the rows you are interested in > and use that to calculate the mean of the breaks column. > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
