[R] Romoving elements from a vector. Looking for the opposite of c(), New user

Thomas Frööjd tfrojd at gmail.com
Thu Nov 15 17:09:25 CET 2007


Not sure i explained it good enough. Ill try with an example

say

x=[3,3,4,4,4,4,5,5,6,8]
z=[3,4,4,5,5]

what i want to get after removing z from x is something like
x=[3,4,4,6,8]


On Nov 15, 2007 3:29 PM, Charilaos Skiadas <cskiadas at gmail.com> wrote:
>
>
> On Nov 15, 2007, at 9:15 AM, Thomas Frööjd wrote:
>
> > Hi
> >
> > I have three vectors say x, y, z. One of them, x contains observations
> > on a variable. To x I want to append all observations from y and
> > remove all from z. For appending c() is easily used
> >
> > x <- c(x,y)
> >
> > But how do I remove all observations in z from x? You can say I am
> > looking for the opposite of c().
>
> If you are looking for the opposite of c, provided you want to remove
> the first part of things, then perhaps this would work:
>
> z<-c(x,y)
> z[-(1:length(x))]
>
> However, if you wanted to remove all appearances of elements of x
> from c(x,y), regardless of whether those elements appear in the x
> part of in the y part, I think you would want:
>
> z[!z %in% x]
>
> Probably there are other ways.
>
> Welcome to R!
>
> > Best regards
>
> Haris Skiadas
> Department of Mathematics and Computer Science
> Hanover College
>
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