Why doesn't this work and is there a better way ? z <-ifelse(t==1 || 2 || 3, 1,0) t <-3 z [1] 1 t <-4 z [1] 1 trying to say ...if t == 1 or if t== 2 or if t ==3 then true, otherwise false -- View this message in context: http://r.789695.n4.nabble.com/Why-doesn-t-this-work-tp3383656p3383656.html Sent from the R help mailing list archive at Nabble.com.
It doesn't work (in R) because it is not written in R. It's written in some other language that looks a bit like R.> t <- 3 > z <- t %in% 1:3 > z[1] TRUE> t <- 4 > z <- t %in% 1:3 > z[1] FALSE>-----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of eric Sent: Thursday, 17 March 2011 1:26 PM To: r-help at r-project.org Subject: [R] Why doesn't this work ? Why doesn't this work and is there a better way ? z <-ifelse(t==1 || 2 || 3, 1,0) t <-3 z [1] 1 t <-4 z [1] 1 trying to say ...if t == 1 or if t== 2 or if t ==3 then true, otherwise false -- View this message in context: http://r.789695.n4.nabble.com/Why-doesn-t-this-work-tp3383656p3383656.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help at 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.
Eric -
What you mean to say is
> t <- 3
> z <- ifelse(t %in% c(1,2,3),1,0)
> z
[1] 1> t <- 4
> z <- ifelse(t %in% c(1,2,3),1,0)
[1] 0
Expressions don't recalculate themselves when you change
the value of a variable that they use. For that, you
would need a function:
> makez = function(t)ifelse(t %in% c(1,2,3),1,0)
> makez(3)
[1] 1> makez(4)
[1] 0
- Phil Spector
Statistical Computing Facility
Department of Statistics
UC Berkeley
spector at stat.berkeley.edu
On Wed, 16 Mar 2011, eric wrote:
> Why doesn't this work and is there a better way ?
>
> z <-ifelse(t==1 || 2 || 3, 1,0)
> t <-3
> z
> [1] 1
> t <-4
> z
> [1] 1
>
> trying to say ...if t == 1 or if t== 2 or if t ==3 then true, otherwise
> false
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/Why-doesn-t-this-work-tp3383656p3383656.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at 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.
>