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

[Gabor Grothendieck]

Try this.  xx and zz are the same as x and z except
they have a sequence number appended.  We then do
a setdiff and remove the sequence numbers.

> xx <- paste(x, seq(x) - match(x, x))
> zz <- paste(z, seq(z) - match(z, z))
> dd <- setdiff(xx, zz)
> as.numeric(sub(" .*", "", dd))
[1] 3 4 4 6 7 8 8 9


On Nov 15, 2007 11:09 AM, Thomas Frööjd <tfrojd at gmail.com> wrote:
> 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
> >
> > ______________________________________________
> > 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.
> >
>
> ______________________________________________
> 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.
>