similar to: Suggestions for 'diff.default'

I found this part in the documentation of 'factor'. 'factor(x, exclude=NULL)' applied to a factor is a no-operation unless there are unused levels: in that case, a factor with the reduced level set is returned. If 'exclude' is used it should also be a factor with the same level set as 'x' or a set of codes for the levels to be excluded.

I apologize if this is not appropriate for this mailing list. In R, there is already functionality to drop unused factor levels. However, I am proposing the code below that I wrote. In some occasions, it was faster than applying function 'factor'. In any case, there is no restriction for anyone to use the code below. droplevels2 <- function(x) { if (is.null(levels(x))) stop("no

In example for function 'stop' in R, there is options(error = expression(NULL)) with comment # don't stop on stop(.) << Use with CARE! >> I was interested, wanted to know how "don't stop on stop(.)" was. So, I tried it. Typing example(stop) at the R prompt and pressing ENTER give this. > example(stop) stop> options(error = expression(NULL))

\b is word boundary. But, unexpectedly, strsplit("dia ma", "\\b") splits character by character. > strsplit("dia ma", "\\b") [[1]] [1] "d" "i" "a" " " "m" "a" > strsplit("dia ma", "\\b", perl=TRUE) [[1]] [1] "d" "i" "a" " "

By "an argument named 'use.names' is included for concatenation", I meant something like this, that someone might try. > c(as.Date("2016-01-01"), use.names=FALSE) use.names "2016-01-01" "1970-01-01" See, 'use.names' is in the output. That's precisely because 'c.Date' doesn't have 'use.names', so

Looking at the code of function 'table' in R devel r71227, I see that the part "remove NA level if it was added only for excluded in factor(a, exclude=.)" is not quite right. In is.na(a) <- match(a0, c(exclude,NA), nomatch=0L) , I think that what is intended is a[a0 %in% c(exclude,NA)] <- NA . So, it should be is.na(a) <- match(a0, c(exclude,NA),

Removal of ans[nas] <- NA from the code of function 'ifelse' in R is not committed (yet). Why? -------------------------------------------- On Mon, 28/11/16, Martin Maechler <maechler at stat.math.ethz.ch> wrote: Subject: Re: [Rd] ifelse() woes ... can we agree on a ifelse2() ? Cc: R-devel at r-project.org, maechler at stat.math.ethz.ch Date: Monday, 28 November, 2016, 10:00

Yes, they work now. I mentioned them partly because the commit description said overflow for large n and partly to be considered for regression tests. -------------------------------------------- On Sat, 19/8/17, Martin Maechler <maechler at stat.math.ethz.ch> wrote: Subject: Re: [Rd] Issues of R_pretty in src/appl/pretty.c Cc: r-devel at r-project.org Date: Saturday, 19 August, 2017,

Here is a patch to function 'stopifnot' that adds 'evaluated' argument and makes 'exprs' argument in 'stopifnot' like 'exprs' argument in 'withAutoprint'. --- stop.R 2019-05-30 14:01:15.282197286 +0000 +++ stop_new.R 2019-05-30 14:01:51.372187466 +0000 @@ -31,7 +31,7 @@ .Internal(stop(call., .makeMessage(..., domain = domain))) }

In R 2.15.2 (and not before), in the definition of function 'diffinv.vector' in package stats, there is difference <- as.integer(differences) I believe differences <- as.integer(differences) is intended, because 'difference' is not referenced anywhere. However, without conversion of 'differences' to integer, 'diffinv.vector' in R 2.15.2 works OK. Also,

I am trying once again. By just changing f <- match(xlevs[f], nlevs) to f <- match(xlevs, nlevs)[f] , function 'factor' in R devel could be made more consistent and back-compatible. Why not picking it? -------------------------------------------- On Sat, 25/11/17, Suharto Anggono Suharto Anggono <suharto_anggono at yahoo.com> wrote: Subject: Re: [Rd] Function

> .Internal(inspect(1:10)) @300e4e8 13 INTSXP g0c0 [NAM(3)] 1 : 10 (compact) > .Internal(inspect(seq(1,10))) @3b6e1f8 13 INTSXP g0c4 [] (len=10, tl=0) 1,2,3,4,5,... > system.time(1:1e7) user system elapsed 0 0 0 > system.time(seq(1,1e7)) user system elapsed 0.05 0.00 0.04 It seems that result of function 'seq' doesn't use compact

useNA <- if (missing(useNA) && !missing(exclude) && !(NA %in% exclude)) "ifany" An example where it change 'table' result for non-factor input, from https://stat.ethz.ch/pipermail/r-help/2005-April/069053.html : x <- c(1,2,3,3,NA) table(as.integer(x), exclude=NaN) I bring the example up, in case that the change in result is not intended.

This is just info. I recently got something like this. > x <- factor(c("A","A","B","B"), levels=c("A","B")) > y <- factor(c("a","b","a","b"), levels=c("a","b")) > table(x, y)[, "a"] / table(x) x A B 0.5 0.5 attr(,"class") [1]

Another possible shortcut definition: assert <- function(exprs) do.call("stopifnot", list(exprs = substitute(exprs), local = parent.frame())) After thinking again, I propose to use ??? ? ? stop(simpleError(msg, call = if(p <- sys.parent()) sys.call(p))) - It seems that the call is the call of the frame where stopifnot(...) is evaluated. Because that is the correct context, I

On 'aggregate data.frame', the URL should be https://stat.ethz.ch/pipermail/r-help/2016-May/438631.html . vector(typeof(ans)) (or vector(storage.mode(ans))) has length zero and can be used to initialize array. Instead of if(missing(default)) , if(identical(default, NA)) could be used. The documentation could then say, for example: "If default = NA (the default), NA of appropriate

>>>>> Martin Maechler <maechler at stat.math.ethz.ch> >>>>> on Mon, 15 Aug 2016 11:07:43 +0200 writes: >>>>> Suharto Anggono Suharto Anggono <suharto_anggono at yahoo.com> >>>>> on Sun, 14 Aug 2016 03:42:08 +0000 writes: >> useNA <- if (missing(useNA) && !missing(exclude) && !(NA %in%

Thanks -- I'll commit a fix after some testing. Best, luke On 04/29/2018 06:22 AM, Duncan Murdoch wrote: > On 28/04/2018 11:11 PM, Suharto Anggono Suharto Anggono via R-devel wrote: >>> .Internal(inspect(1:10)) >> @300e4e8 13 INTSXP g0c0 [NAM(3)]? 1 : 10 (compact) >>> .Internal(inspect(seq(1,10))) >> @3b6e1f8 13 INTSXP g0c4 [] (len=10, tl=0) 1,2,3,4,5,...

In the code for 'aggregate.formula', there is if (as.character(formula[[2L]] == ".")) I believe that it is meant to be if (as.character(formula[[2L]]) == ".") However, if (as.character(formula[[2L]] == ".")) gives the expected result. Tracing: - formula[[2L]] == "." is equivalent to as.character(formula[[2L]]) == "." From the help page for

http://stackoverflow.com/questions/6065724/assigning-value-to-a-variable-that-has-a-dot-in-the-name made me realize this. The context is 'a' is assigned to ret$log.id, but then ret$log returns "a" and ret$l also returns "a". There is a comment from Charles on the question: "Also see options(warnPartialMatchDollar=T) if you want to track these." But, in