Here are some examples of data aggregation functions in R: http://www.slideshare.net/djandrija/data-aggregation-in-r
http://www.psychwire.co.uk/2011/04/data-aggregation-in-r-plyr-sqldf-and-data-table/ Andrija On Mon, Feb 4, 2013 at 10:29 AM, Benjamin Gillespie <gy...@leeds.ac.uk>wrote: > Hi guys, > > I hope you can help me with this (probably) simple query: > > I have a data frame: > > -------------------------- > > a=c(1,1,1,1,1,1,2,2,2,2,2,2) > b=c(1,1,1,2,3,4,1,1,2,2,3,4) > c=c(400,200,300,100,500,300,200,100,500,400,200,100) > > > data=data.frame(a=a,b=b,c=c) > > -------------------------- > > And I would like to get the following output: > > -------------------------- > > b > a 1 2 3 4 > 1 900 100 500 300 > 2 300 900 200 100 > > -------------------------- > > The values in the output represent the sum of values "c" in data frame > "data", for each "a" and "b" combination. > > For example, where "a" = 1 and "b" = 1, the output is 400+200+300 = 900. > > Please would anyone be able to provide a script to create my desired > output? > > Many thanks in advance, > > Ben Gillespie > Research Postgraduate > > School of Geography > University of Leeds > Leeds > LS2 9JT > > > ______________________________________________ > R-help@r-project.org mailing list > 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 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.
