Well, that's a convincing argument, but maybe it's the name that's worrying some of us. Maybe it would be more intuitive if called set.na (sorry, I mean setNA).
Also "is.na<-" cannot be used to create a new variable of NAs, so is not a universal method, which is a shame for its advocates. I note also that for a vector you can assign a new NA using either TRUE or FALSE: > a <- 1:3 > is.na(a[4])<-F > a [1] 1 2 3 NA For a list, assigning F leaves the "new" element set to NULL. Mind you, I suspect this would be a particularly stupid thing to do, so I'm not going to lose any sleep over R's reaction to it. > > -----Original Message----- > From: Prof Brian Ripley [mailto:[EMAIL PROTECTED] > I don't think it can ever `go wrong', but it can do things other than > the > user intends. The intention of is.na<- is clearer, and so > perhaps user > error is less likely? That is the thinking behind the > function, anyway. Simon Fear Senior Statistician Syne qua non Ltd Tel: +44 (0) 1379 644449 Fax: +44 (0) 1379 644445 email: [EMAIL PROTECTED] web: http://www.synequanon.com Number of attachments included with this message: 0 This message (and any associated files) is confidential and\...{{dropped}} ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help