People, What I mean is, is there an elegant way to do this: This: !(1,2,3,4,5) would give this: (2,3,4,5, 6,8,10, 12,15, 20) and this: !(1,2,NA,4,5) would give this: (2,4,5, 8,10, 20) ? Thanks! Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: phil at pricom.com.au
? Wed, 21 Jun 2023 03:13:52 +1000 Philip Rhoades via R-help <r-help at r-project.org> ?????:> This: > > !(1,2,3,4,5) > > would give this: > > (2,3,4,5, 6,8,10, 12,15, 20)Do you mean taking a product of every element of the vector with all following vector elements? A relatively straightforward way would be (given your vector stored in `x`): unlist(lapply(seq_along(x), function(i) x[i] * x[-(1:i)])) (I'm sure it could be golfed further.)> and this: > > !(1,2,NA,4,5) > > would give this: > > (2,4,5, 8,10, 20)The previous solution seems to give your vector interspersed a bunch of NAs, so one way to continue would be to filter it using v[!is.na(v)]. -- Best regards, Ivan
Well, I think this is reasonable elegant, but ymmv. Turning it into a function and removing NA values is left for you.> x <- 1:5 > unlist(sapply(seq(1, length(x) - 1), function(i){x[i] * x[seq(i + 1, length(x))]}))[1] 2 3 4 5 6 8 10 12 15 20> > x <- c(1, 2, NA, 4, 5) > unlist(sapply(seq(1, length(x) - 1), function(i){x[i] * x[seq(i + 1, length(x))]}))[1] 2 NA 4 5 NA 8 10 NA NA 20 Sarah On Tue, Jun 20, 2023 at 1:15?PM Philip Rhoades via R-help <r-help at r-project.org> wrote:> > People, > > What I mean is, is there an elegant way to do this: > > This: > > !(1,2,3,4,5) > > would give this: > > (2,3,4,5, 6,8,10, 12,15, 20) > > and this: > > !(1,2,NA,4,5) > > would give this: > > (2,4,5, 8,10, 20) > > ? > > Thanks! > > Phil. > -- > Philip Rhoades > > PO Box 896 > Cowra NSW 2794 > Australia > E-mail: phil at pricom.com.au > > ______________________________________________ > R-help at 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.-- Sarah Goslee (she/her) http://www.numberwright.com
vf <- function(x){
o <- outer(x, x)
as.vector(na.omit(o[lower.tri(o)]))
}
vf(1:5)
vf(c(1,2,NA,4,5))
Best,
Uwe Ligges
On 20.06.2023 19:13, Philip Rhoades via R-help wrote:> People,
>
> What I mean is, is there an elegant way to do this:
>
> This:
>
> ? !(1,2,3,4,5)
>
> would give this:
>
> ? (2,3,4,5, 6,8,10, 12,15, 20)
>
> and this:
>
> ? !(1,2,NA,4,5)
>
> would give this:
>
> ? (2,4,5, 8,10, 20)
>
> ?
>
> Thanks!
>
> Phil.