[R] Choice of data.frame column by index?

[Moshe Olshansky]

This won't work since it produces a matrix (try this).

What should work is
x[(1:nrow(x)) + nrow(x)*(v-1)]

--- Johannes Graumann <johannes_graumann at web.de>
wrote:

> Thanks!
> 
> Joh
> 
> On Thursday 23 August 2007 12:01:50 you wrote:
> > x[cbind(1:nrow(x), the.vector)]
> >
> > Patrick Burns
> > patrick at burns-stat.com
> > +44 (0)20 8525 0696
> > http://www.burns-stat.com
> > (home of S Poetry and "A Guide for the Unwilling S
> User")
> >
> > Johannes Graumann wrote:
> > >Hello,
> > >
> > >Imagine a data frame like so:
> > >
> > >  Intensity0 Intensity1
> > >1   767432.1   451743.4
> > >2  3998988.0  4642145.0
> > >3   818974.6   552315.8
> > >
> > >and a vector like so:
> > >
> > >[1] 1 2 1
> > >
> > >How can I get R to produce a vector that contains
> the value in one column
> > > or the other depending on the vector? The result
> should look like
> > >
> > >[1] 767432.1 4642145.0 818974.6
> > >
> > >Thanks for any hints!
> > >
> > >Joh
> > >
> > >______________________________________________
> > >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 and
> provide commented,
> > > minimal, self-contained, reproducible code.
> 
> 
> > ______________________________________________
> R-help at stat.math.ethz.ch mailing list
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained,
> reproducible code.
>