So that's how that works! Thanks. On Fri, Jan 22, 2016 at 1:32 PM, Joe Ceradini <joecerad...@gmail.com> wrote: > Does this do what you want? > > aggregate(Nuclei ~ Slide, example, sum) > > On Fri, Jan 22, 2016 at 12:20 PM, Ed Siefker <ebs15...@gmail.com> wrote: >> >> Aggregate does the right thing with column names when passing it >> numerical coordinates. >> Given a dataframe like this: >> >> Nuclei Positive Nuclei Slide >> 1 133 96 A1 >> 2 96 70 A1 >> 3 62 52 A2 >> 4 60 50 A2 >> >> I can call 'aggregate' like this: >> >> > aggregate(example[1], by=example[3], sum) >> Slide Nuclei >> 1 A1 229 >> 2 A2 122 >> >> But that means I have to keep track of which column is which number. >> If I try it the >> easy way, it doesn't keep track of column names and it forces me to >> coerce the 'by' >> to a list. >> >> > aggregate(example$Nuclei, by=list(example$Slide), sum) >> Group.1 x >> 1 A1 229 >> 2 A2 122 >> >> Is there a better way to do this? Thanks >> -Ed >> >> ______________________________________________ >> 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. > > > > > -- > Cooperative Fish and Wildlife Research Unit > Zoology and Physiology Dept. > University of Wyoming > joecerad...@gmail.com / 914.707.8506 > wyocoopunit.org >
______________________________________________ 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.