Hi Steven, Try this:
R> apply(m,1, function(x) ifelse(all(is.na(x)), NA, max(x, na.rm = TRUE))) [1] NA 8 9 See ?ifelse, ?all and ?max for more information. HTH, Jorge On Sun, Apr 18, 2010 at 12:16 AM, steven mosher <> wrote: > Is there a simple way to calculate the maximum for a row or column of a > matrix when there are NA,s present. > > # given a matrix that has any number of NA per row > > m<-matrix(c(seq(1,9)),nrow=3) > > m > [,1] [,2] [,3] > [1,] 1 4 7 > [2,] 2 5 8 > [3,] 3 6 9 > > m[3,1]=NA > > m[1,]=NA > > m > [,1] [,2] [,3] > [1,] NA NA NA > [2,] 2 5 8 > [3,] NA 6 9 > > # applying max to rows doesnt work as max returns > # NA if any of the elements is NA. > > row_max<-apply(m,1,max) > > row_max > [1] NA 8 NA > > # my desired result given m would be: > # NA, 8, 9 > > [[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. > [[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.
