Hi Jonny, On Tue, Oct 18, 2011 at 1:02 PM, Jonny Armstrong <jonny5armstr...@gmail.com> wrote: > I am analyzing the spatial distribution of fish in a stream. The stream is > divided into equally sized units, and the number of fish in each unit is > counted. My problem is that my dataset is missing rows where the count in a > unit equals zero. I need to create zero data for the missing units. > > For example: > day<-(c(rep(4,8),rep(6,8))) > unit<-c(seq(1,8,1),seq(2,16,2)) > value<-floor(rnorm(16,25,10)) > x<-cbind(day,unit,value)
Thanks for the actual reproducible example. > x > day unit value > [1,] 4 1 19 > [2,] 4 2 15 > [3,] 4 3 16 > [4,] 4 4 20 > [5,] 4 5 17 > [6,] 4 6 15 > [7,] 4 7 14 > [8,] 4 8 29 > [9,] 6 2 18 > [10,] 6 4 22 > [11,] 6 6 27 > [12,] 6 8 16 > [13,] 6 10 45 > [14,] 6 12 36 > [15,] 6 14 34 > [16,] 6 16 13 > > Lets say the stream has 16 units. For each day, I want to fill in rows for > any missing units (e.g., units 9-16 for day 4, the odd numbered units on day > 6) with values of zero. Here's one option, though it may not be terribly concise: all.samples <- expand.grid(day=unique(x[,"day"]), unit=1:16) all.samples <- all.samples[order(all.samples[,"day"], all.samples[,"unit"]),] x.final <- merge(x, all.samples, all.y=TRUE) x.final[is.na(x.final[,"value"]), "value"] <- 0 Sarah > Does anyone know a relatively concise way to do this? > Thank you. > > [[alternative HTML version deleted]] > -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ 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.
