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 [[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.
