Try this:
subset(pop, (ave(Area, Area, FUN = length) == 1 | ave(Area, Area, FUN = function(x)cumsum(prop.table(x))) < 0.7 & Area %in% 1:3)) On Fri, Mar 18, 2011 at 2:48 PM, Nicolas Gutierrez <nicol...@uw.edu> wrote: > Hello, > > One more question.. I have the data.frame "pop": > > xloc yloc gonad ind Ene W Area > 1 23 20 516.74 1 0.02 20.21 1 > 2 23 20 1143.20 1 0.02 20.21 1 > 3 23 20 250.00 1 0.02 20.21 1 > 4 22 15 251.98 1 0.02 18.69 2 > 5 22 15 598.08 1 0.02 18.69 2 > 6 21 19 250.00 1 0.02 20.21 3 > 7 22 20 251.98 1 0.02 18.69 4 > 8 22 20 598.08 1 0.02 18.69 4 > > and I need to extract 50% (or rounded) of the rows for each Area (from Area > 1 to 3 only): > > xloc yloc gonad ind Ene W Area > 1 23 20 516.74 1 0.02 20.21 1 > 2 23 20 1143.20 1 0.02 20.21 1 > 4 22 15 251.98 1 0.02 18.69 2 > 6 21 19 250.00 1 0.02 20.21 3 > > I did this within a loop, but considering my data.frame has more than 10,000 > rows and within other loops it makes my code run forever! Any hints? > Thanks!! > > Nico > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.