?tapply or better yet
?ave ## a wrapper for tapply allows it to be done without extraction. Cheers, Bert Bert Gunter "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." -- Clifford Stoll On Fri, Sep 11, 2015 at 9:02 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. ______________________________________________ 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.
