I am neither a programmer nor a professional statistician but this topic interests me because:
1) I remember from long, long ago that S had a way to create labels that could denote multiple ways in which a value could be missing that was sometimes useful to me as my field sometimes has such situations. In R I handle this with a second variable but I can see that using attributes is cleaner and might have real benefits when doing missing value analyses. That might raise questions about whether some of the nice packages that help with missing value analyses would take on board some standardised use of attributes for this. 2) I think Marc's question LDL/UDL is about a very particular sort of value that isn't missing and _is_ censored but not in survival analysis meaning of censored. (At least, it's not the same to my mind, perhaps it is? To me the difference is that I most often hit the LDL/UDL issue in data that don't have much, or any, time frame.) Again, this comes up a lot for me where people are given limited possible answers in questionnaires and I've often wondered if I should explore simulating probability models for an the "off the edge" value on a latent variable beneath/behind the measured responses. I'd be very grateful to hear of any work in R packages (to stay only just "off the edge" of the posting guide). Or of any work a long the lines that Duncan offers, that sort of pulls this toward base R, though that sounds to me as if it would be a huge undertaking. I'm very interested to hear any thoughts on either aspect. Seasonal (mutivalued) greetings to all! Chris ----- Original Message ----- > From: "Duncan Murdoch" <murdoch.dun...@gmail.com> > To: "Marc Girondot" <marc_...@yahoo.fr>, r-help@r-project.org > Sent: Tuesday, 21 December, 2021 10:26:12 > Subject: Re: [R] Creating NA equivalent > On 20/12/2021 11:41 p.m., Marc Girondot via R-help wrote: >> Dear members, >> >> I work about dosage and some values are bellow the detection limit. I >> would like create new "numbers" like LDL (to represent lower than >> detection limit) and UDL (upper the detection limit) that behave like >> NA, with the possibility to test them using for example is.LDL() or >> is.UDL(). >> >> Note that NA is not the same than LDL or UDL: NA represent missing data. >> Here the data is available as LDL or UDL. >> >> NA is built in R language very deep... any option to create new version >> of NA-equivalent ? >> > > There was a discussion of this back in May. Here's a link to one > approach that I suggested: > > https://stat.ethz.ch/pipermail/r-devel/2021-May/080776.html > > Read the followup messages, I made at least one suggested improvement. > I don't know if anyone has packaged this, but there's a later version of > the code here: > > https://stackoverflow.com/a/69179441/2554330 > > Duncan Murdoch > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. -- Chris Evans (he/him) <ch...@psyctc.org> Visiting Professor, UDLA, Quito, Ecuador & Honorary Professor, University of Roehampton, London, UK. Work web site: https://www.psyctc.org/psyctc/ CORE site: https://www.coresystemtrust.org.uk/ Personal site: https://www.psyctc.org/pelerinage2016/ OMbook: https://ombook.psyctc.org/book/ ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
