>>>>> Suharto Anggono Suharto Anggono via R-devel <r-devel@r-project.org> >>>>> on Sun, 7 Aug 2016 15:32:19 +0000 writes:
> This is an example from > https://stat.ethz.ch/pipermail/r-help/2007-May/132573.html . > With R 2.7.2: > > a <- c(1, 1, 2, 2, NA, 3); b <- c(2, 1, 1, 1, 1, 1) > > table(a, b, exclude = NULL) > b > a 1 2 > 1 1 1 > 2 2 0 > 3 1 0 > <NA> 1 0 > With R 3.3.1: > > a <- c(1, 1, 2, 2, NA, 3); b <- c(2, 1, 1, 1, 1, 1) > > table(a, b, exclude = NULL) > b > a 1 2 <NA> > 1 1 1 0 > 2 2 0 0 > 3 1 0 0 > <NA> 1 0 0 > > table(a, b, useNA = "ifany") > b > a 1 2 > 1 1 1 > 2 2 0 > 3 1 0 > <NA> 1 0 > > table(a, b, exclude = NULL, useNA = "ifany") > b > a 1 2 <NA> > 1 1 1 0 > 2 2 0 0 > 3 1 0 0 > <NA> 1 0 0 > For the example, in R 3.3.1, the result of 'table' with > exclude = NULL includes NA even if NA is not present. It is > different from R 2.7.2, that comes from factor(exclude = NULL), > that includes NA only if NA is present. I agree that this (R 3.3.1 behavior) seems undesirable and looks wrong, and the old (<= 2.2.7) behavior for table(a,b, exclude=NULL) seems desirable to me. > >From R 3.3.1 help on 'table', in "Details" section: > 'useNA' controls if the table includes counts of 'NA' values: the allowed > values correspond to never, only if the count is positive and even for zero > counts. This is overridden by specifying 'exclude = NULL'. > Specifying 'exclude = NULL' overrides 'useNA' to what value? The > documentation doesn't say. Looking at the code of function 'table', the value > is "always". Yes, it should be documented what happens for this case, (but read on ...) > For the example, in R 3.3.1, the result like in R 2.7.2 can be obtained with > useNA = "ifany" and 'exclude' unspecified. Yes. What should we do? I currently think that we'd want to change the line useNA <- if (!missing(exclude) && is.null(exclude)) "always" to useNA <- if (!missing(exclude) && is.null(exclude)) "ifany" # was "always" which would not even contradict documentation, as indeed you mentioned above, the exact action here had not been documented. The change above at least does not break any of the standard R tests ('make check-all', i.e., including the recommended packages), which for me confirms that it may be "what is best"... ---- Thank you for mentioning the important consequence for summary(<logical>). They can helping insight what a "probably best" behavior should be for these cases of table(). Martin Maechler, ETH Zurich > The result of 'summary' of a logical vector is affected. As mentioned in > http://stackoverflow.com/questions/26775501/r-dropping-nas-in-logical-column-levels > , in the code of function 'summary.default', for logical, table(object, > exclude = NULL) is used. > With R 2.7.2: > > log <- c(NA, logical(4), NA, !logical(2), NA) > > summary(log) > Mode FALSE TRUE NA's > logical 4 2 3 > > summary(log[!is.na(log)]) > Mode FALSE TRUE > logical 4 2 > > summary(TRUE) > Mode TRUE > logical 1 > With R 3.3.1: > > log <- c(NA, logical(4), NA, !logical(2), NA) > > summary(log) > Mode FALSE TRUE NA's > logical 4 2 3 > > summary(log[!is.na(log)]) > Mode FALSE TRUE NA's > logical 4 2 0 > > summary(TRUE) > Mode TRUE NA's > logical 1 0 > In R 3.3.1, "NA's' is always in the result of 'summary' of a logical vector. > It is unlike 'summary' of a numeric vector. > On the other hand, in R 3.3.1, FALSE is not in the result of 'summary' of a > logical vector that doesn't contain FALSE. > I prefer the result of 'summary' of a logical vector like in R 2.7.2, or, > alternatively, the result that always includes all possible values: FALSE, > TRUE, NA. I tend to agree, and strongly prefer the 'R(<=2.7.2)'-behavior for table() {and hence summary(<logical>)}. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
