[R] Adding values to the end of a vector?

[Daniel Almirall]

I am curious.  How are these suggestions different (better, worse?) from

 x <- NULL
 for (i in 1:5) x <- c(x, i)


Thanks,
Danny



On Tue, 4 Jan 2005, John Fox wrote:

> Dear Dan,
>
> The following also works:
>
> > x <- numeric(0)
> > for (i in 1:5) x[i] <- i
> > x
> [1] 1 2 3 4 5
>
> It's worth noting, however, that extending a vector in this manner can be
> very inefficient for large vectors, since the vector is recopied each time.
> If you can anticipate the number of elements (or place an upper bound on
> it), then it's better to do something like
>
> > x <- numeric(5)
> > for (i in 1:5) x[i] <- i
>
> I hope this helps,
>  John
>
> --------------------------------
> John Fox
> Department of Sociology
> McMaster University
> Hamilton, Ontario
> Canada L8S 4M4
> 905-525-9140x23604
> http://socserv.mcmaster.ca/jfox
> --------------------------------
>
> > -----Original Message-----
> > From: r-help-bounces at stat.math.ethz.ch
> > [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Liaw, Andy
> > Sent: Tuesday, January 04, 2005 8:51 AM
> > To: 'Dan Bolser'; R mailing list
> > Subject: RE: [R] Adding values to the end of a vector?
> >
> > Is this what you're looking for?
> >
> > > x <- numeric(0)
> > > for (i in 1:5) x <- append(x, i)
> > > x
> > [1] 1 2 3 4 5
> >
> > Andy
> >
> >
> > > From: Dan Bolser
> > >
> > > I want to add values onto the end of a vector, for example...
> > >
> > > x <- vector
> > >
> > > for (i in 1:5){
> > >   add_to_end_of_vector(i,x)
> > > }
> > >
> > > I just cant find the answer to this question!
> > >
> > >
> > > Sorry for such a basic question, I tried...
> > >
> > > x <- c()
> > >
> > > for (i in 1:5) x[length(x)] <- i
> > >
> > > but it didn't work.
> > >
> > > ______________________________________________
> > > R-help at stat.math.ethz.ch mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide!
> > > http://www.R-project.org/posting-guide.html
> > >
> > >
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide!
> > http://www.R-project.org/posting-guide.html
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>
>
>