Hi Bert, What troubles me about this is that something like detectable level(s) is determined at a particular time and may change. Censoring in survival tells us that the case lasted "at least this long". While a less than detectable value doesn't give any useful information apart from perhaps "non-zero", an over limit value gives something like censoring with "at least this much". However, it is more difficult to conceptualize and I suspect, to quantify. To me, the important information is that we think there _may be_ a value but we don't (yet?) know it.
Jim On Wed, Dec 22, 2021 at 9:56 AM Bert Gunter <bgunter.4...@gmail.com> wrote: > > But you appear to be missing something, Jim -- see inline below (and > the original post): > > Bert > > > On Tue, Dec 21, 2021 at 2:00 PM Jim Lemon <drjimle...@gmail.com> wrote: > > > > Please pardon a comment that may be off-target as well as off-topic. > > This appears similar to a number of things like fuzzy logic, where an > > instance can take incompatible truth values. > > > > It is known that an instance may have an attribute with a numeric > > value, but that value cannot be determined. > Yes, but **something** about the value is known: that it is > an upper > value or < a lower value. Such information should be used > (censoring!), not characterized as completely unknown. Think about it > in terms of survival time: saying that a person lasted longer than k > months is much more informative than saying that how long they lasted > is completely unknown! > > > > > It seems to me that an appropriate designation for the value is Unk, > > perhaps with an associated probability of determination to distinguish > > it from NA (it is definitely not known). > > > > Jim > > > > On Wed, Dec 22, 2021 at 6:55 AM Avi Gross via R-help > > <r-help@r-project.org> wrote: > > > > > > I wonder if the package Adrian Dușa created might be helpful or point you > > > along the way. > > > > > > It was eventually named "declared" > > > > > > https://cran.r-project.org/web/packages/declared/index.html > > > > > > With a vignette here: > > > > > > https://cran.r-project.org/web/packages/declared/vignettes/declared.pdf > > > > > > I do not know if it would easily satisfy your needs but it may be a step > > > along the way. A package called Haven was part of the motivation and > > > Adrian wanted a way to import data from external sources that had more > > > than one category of NA that sounds a bit like what you want. His > > > functions should allow the creation of such data within R, as well. I am > > > including him in this email if you want to contact him or he has > > > something to say. > > > > > > > > > -----Original Message----- > > > From: R-help <r-help-boun...@r-project.org> On Behalf Of Duncan Murdoch > > > Sent: Tuesday, December 21, 2021 5:26 AM > > > To: Marc Girondot <marc_...@yahoo.fr>; r-help@r-project.org > > > 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. > > > > > > ______________________________________________ > > > 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. > > > > ______________________________________________ > > 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. ______________________________________________ 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.
