Hi Marc, This may be a helpful link: http://stackoverflow.com/questions/16074384/specify-different-types-of-missing-values-nas > On Nov 9, 2014, at 1:07 PM, Marc Girondot <marc_...@yahoo.fr> wrote: > > Dear member list, > > In many experimental sciences, there is a lower detection limit (LDL) when a > dosage of a product is done. Then some samples are evaluated to be below this > limit. > I search for the best way to indicate in a data.frame that some values are > such LDL. Ideally, an equivalent of NA would be the best. > Until now I manage by indicating all the column in characters. > So the question is: is it possible to define a value that could be named LDL > and that could take place in vectors or data.frame such as: > v <- c(0.2, 0.28, LDL, 0.9) is the same way that NA can be used. > with of course a function is.ldl(v) that would return F F T F > > Thanks a lot for any direction to solve this > > Marc > > ______________________________________________ > 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.
______________________________________________ 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.
