2009/3/29 baptiste auguie <[email protected]> > Hi, > Thanks Dott. baptiste,
but I wish not the Sum of element but count the numeber of element and obtain a new data.frame. Like your data.frame: myData library(library(plyr) # create a data.frame myData <- data.frame(ID=rep(c(1:4),each=4), count=abs(ceiling(rnorm(16,8,4)))) #count the number of sample in each ID area count_myData <- ddply(myData, .(ID), transform, sum = sum(count >=0, na.rm = T)) ID count sum 1 1 0 4 2 1 9 4 3 1 11 4 4 1 16 4 5 2 9 4 6 2 8 4 7 2 11 4 8 2 10 4 9 3 16 4 10 3 1 4 11 3 0 4 12 3 8 4 13 4 8 4 14 4 10 4 15 4 11 4 16 4 5 4 now I searching to create a new DF like this: ID count 1 4 2 4 3 4 4 4 Thanks Gianni > could you provide an example for the data in "sample"? (incidentally, note > that sample is already the name of a built-in function) > > I'm guessing you could do something like, > > >> library(doBy) >> summaryBy(count~ID, data= count_myData, FUN=sum) >> > > tested with, > > count_myData <- data.frame(ID=rep(c(1:4),each=4), > count=abs(ceiling(rnorm(16,8,4)))) > > > hope this helps, > > baptiste > > > On 29 Mar 2009, at 17:54, gianni lavaredo wrote: > > Dear R user, >> >> Thanks for this sunday attention about my problem. I have a data.frame >> like >> this example: >> >> count_myData >> >> ID: 1,1,1,1,2,2,2,3,3,3,3,3,4,4,4,4,4,4 >> count: 4,4,4,4,3,3,3,5,5,5,5,5,6,6,6,6,6,6 >> >> this data.frame derived from this code >> >> count_myData <- ddply(sample, .(ID), transform, sum = sum(Z >=0, na.rm = >> T)) >> >> with this I have the number of sample inside of area with ID 1, ID 2 ID 3 >> etc etc. >> Now I need a data.frame like this >> >> new_myData >> ID:1,2,3,4 >> count:4,3,5,6 >> >> Thanks Gianni >> >> [[alternative HTML version deleted]] >> >> _______________________________________________ >> R-sig-Geo mailing list >> [email protected] >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >> > > _____________________________ > > Baptiste Auguié > > School of Physics > University of Exeter > Stocker Road, > Exeter, Devon, > EX4 4QL, UK > > Phone: +44 1392 264187 > > http://newton.ex.ac.uk/research/emag > ______________________________ > > [[alternative HTML version deleted]]
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