Dear John, The behaviour of R is reasonable, since, in your example, 4 + NA should in general be NA (i.e., missing). You can do what you want by changing NAs to 0s:
> a[is.na(a)] <- 0 > a + b [1] 5 4 8 I hope this helps, John -------------------------------- John Fox Department of Sociology McMaster University Hamilton, Ontario Canada L8S 4M4 905-525-9140x23604 http://socserv.mcmaster.ca/jfox -------------------------------- > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of John Kane > Sent: Monday, May 01, 2006 12:26 PM > To: R R-help > Subject: [R] Adding elements in an array where I have missing data. > > This is a simple question but I cannot seem to find the answer. > I have two vectors but with missing data and I want to add > them together with the NA's being ignored. > > Clearly I need to get the NA ignored. na.action? > > I have done some searching and cannot get na.action to help. > This must be a common enough issue that the answer is staring > me in the face but I just don't see it. > > Simple example > a <- c(2, NA, 3) > b <- c(3,4, 5) > > What I want is > c <- a + b where > c is ( 5 , 4 ,8) > > However I get > c is (5,NA, 8) > > What am I missing? Or do I somehow need to recode the NA's > as missing? > > Thanks > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html