Try something like this: amn <- tapply(a[,i], a[, 1], colSums, na.rm=TRUE))
but since the result of the tapply is a vector, you can also use: amn <- tapply(a[,i], a[, 1],sum, na.rm=TRUE)) On Fri, Nov 14, 2008 at 6:47 PM, Stephanie Shaw <[EMAIL PROTECTED]> wrote: > Hello, > > I am using tapply to pull out data by the day of week and then perform > functions (e.g. mean). I would like to have the number of values used for > the calcuation for the functions, sorted by each day of week. A number of > entries in any given column are NAs. > > I have tried the following code and simple variants with no luck. > > for (i in 1:length(a[1,])){ > x<-tapply(a[,i],a[,1],mean, na.rm=TRUE) > amn<-tapply(a[,i],a[,1],colSums(!is.na),na.rm=T)} > Adding an explicit argument to colSums(!is.na) {e.g. colSums(!is.na(a[,i]))} > produced an error that said colSums was not a function. Trying an > imbedded tapply instead of the colSums didn't work either. Using the sum > function added the values, not the count of the values. > > Thank you for any suggestions, > Stephanie > > [[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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.