Just as a way to save a bit of typing, instead of > as.logical(0:4) [1] FALSE TRUE TRUE TRUE TRUE
> !!(0:4) [1] FALSE TRUE TRUE TRUE TRUE DO NOTE that the parentheses in the second expression should never be omitted, a possible reason to prefer the as.logical() construction. Also note that !! "acts [only] on raw, logical and number-like vectors," whereas as.logical() is more general. e.g. (from ?logical): > charvec <- c("FALSE", "F", "False", "false", "fAlse", "0", + "TRUE", "T", "True", "true", "tRue", "1") > as.logical(charvec) [1] FALSE FALSE FALSE FALSE NA NA TRUE TRUE TRUE TRUE NA NA > !!charvec Error in !charvec : invalid argument type Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Wed, Jun 23, 2021 at 8:31 AM Eric Berger <ericjber...@gmail.com> wrote: > In my code, instead of 't', I name a vector of indices with a meaningful > name, such as idxV, to make it obvious. > > Alternatively, a minor change in your style would be to replace your > definition of t by > > t <- as.logical(c(1,1,1,0,0)) > > HTH, > Eric > > > On Wed, Jun 23, 2021 at 6:11 PM Phillips Rogfield <thebudge...@gmail.com> > wrote: > > > I make the same mistake all over again. > > > > In particular, suppose we have: > > > > a = c(1,2,3,4,5) > > > > and a variable that equals 1 for the elements I want to select: > > > > t = c(1,1,1,0,0) > > > > To select the first 3 elements. > > > > The problem is that > > > > a[t] > > > > would repeat the first element 3 times ..... > > > > I have to either convert `t` to boolean: > > > > a[t==1] > > > > Or use `which` > > > > a[which(t==1)] > > > > How can I "spot" this error? > > > > It often happens in long scripts. > > > > Do I have to check the type each time? > > > > Do you have any suggestions? > > > > ______________________________________________ > > 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. > > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.