Eric - What you're describing is taking the mean of each row while ignoring missing values:
apply(DF,1,mean,na.rm=TRUE)
[1] 22.60 NaN NaN NaN NaN NaN NaN NaN 102.00 19.20 [11] 19.20 NaN NaN NaN 11.80 7.62 NaN NaN NaN NaN [21] NaN 75.00 NaN 18.00 NaN 12.90 If this isn't suitable for your larger problem, please describe that problem in greater detail. - Phil Spector Statistical Computing Facility Department of Statistics UC Berkeley spec...@stat.berkeley.edu On Fri, 25 Jun 2010, emorway wrote:
Forum, Using the following data: DF<-read.table(textConnection("A B 22.60 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 102.00 NA 19.20 NA 19.20 NA NA NA NA NA NA NA 11.80 NA 7.62 NA NA NA NA NA NA NA NA NA NA NA 75.00 NA NA NA 18.30 18.2 NA NA NA NA 8.44 NA 18.00 NA NA NA 12.90 NA"),header=T) closeAllConnections() The second column is a duplicate reading of the first column, and when two values are available, I would like to average column 1 and 2 (example code below). But if there is only one reading, I would like to retain it, but I haven't found a good way to exclude NA's using the following code: t(as.matrix(aggregate(t(as.matrix(DF)),list(rep(1:1,each=2)),mean)[,-1])) Currently, row 24 is the only row with a returned value. I'd like the result to return column "A" if it is the only available value, and average where possible. Of course, if both columns are NA, NA is the only possible result. The result I'm after would look like this (row 24 is an avg): 22.60 NA NA NA NA NA NA NA 102.00 19.20 19.20 NA NA NA 11.80 7.62 NA NA NA NA NA 75.00 NA 18.25 NA NA 8.44 18.00 NA 12.90 This is a small example from a much larger data frame, so if you're wondering what the deal is with list(), that will come into play for the larger problem I'm trying to solve. Respectfully, Eric -- View this message in context: http://r.789695.n4.nabble.com/Average-2-Columns-when-possible-or-return-available-value-tp2269049p2269049.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
______________________________________________ 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.