Thanks you for the quick and helpful replies. Problem solved. Jonny On Tue, Oct 18, 2011 at 11:33 AM, David Winsemius <dwinsem...@comcast.net>wrote:
> > On Oct 18, 2011, at 2:24 PM, Sarah Goslee wrote: > > 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. >>> >> > I could not figure out what you wanted precisely. If "day" is the row > designator, and you want values by 'unit' and 'day' with zeros for the > missing, then that is exactly what `xtab` delivers: > > > xtabs(value ~ day+unit, data=x) > unit > day 1 2 3 4 5 6 7 8 10 12 14 16 > 4 25 34 3 25 38 18 19 33 0 0 0 0 > 6 0 22 0 42 0 37 0 4 12 31 17 28 > > You cannot get much more concise than that. > > -- > david. > >> >> 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 <http://www.functionaldiversity.org> >> >> ______________________________**________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help> >> PLEASE do read the posting guide http://www.R-project.org/** >> posting-guide.html <http://www.R-project.org/posting-guide.html> >> and provide commented, minimal, self-contained, reproducible code. >> > > David Winsemius, MD > West Hartford, CT > > [[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.
