Re: [R] How to turn a string into a variable name ?

From: Ng Stanley <stanleyngkl_at_gmail.com>
Date: Fri, 14 Mar 2008 16:18:44 +0800

Thanks everyone.

On 3/14/08, Simon Blomberg <s.blomberg1_at_uq.edu.au> wrote:
>
> Or maybe use assign?
>
> > assign("natural_nums", 1:10)
> > natural_nums
> [1] 1 2 3 4 5 6 7 8 9 10
> >
>
> Cheers,
>
> Simon.
>
> On Fri, 2008-03-14 at 14:39 +1000, Bill.Venables_at_csiro.au wrote:
> > I'm not sure why you would wish to do so, but it can be done:
> >
> > > natural_nums <- 1:10
> > > even_nums <- seq(2,10, by = 2)
> > > types <- c("natural_nums", "even_nums")
> >
> > > types <- lapply(types, as.name) ## list of variable names
> > > types
> > [[1]]
> > natural_nums
> >
> > [[2]]
> > even_nums
> >
> > > eval(types[[1]])
> > [1] 1 2 3 4 5 6 7 8 9 10
> > > eval(types[[2]])
> > [1] 2 4 6 8 10
> >
> >
> > Bill Venables
> > CSIRO Laboratories
> > PO Box 120, Cleveland, 4163
> > AUSTRALIA
> > Office Phone (email preferred): +61 7 3826 7251
> > Fax (if absolutely necessary): +61 7 3826 7304
> > Mobile: +61 4 8819 4402
> > Home Phone: +61 7 3286 7700
> > mailto:Bill.Venables_at_csiro.au
> > http://www.cmis.csiro.au/bill.venables/
> >
> > -----Original Message-----
> > From: r-help-bounces_at_r-project.org [mailto:r-help-bounces_at_r-project.org]
> > On Behalf Of Ng Stanley
> > Sent: Friday, 14 March 2008 1:27 PM
> > To: r-help
> > Subject: [R] How to turn a string into a variable name ?
> >
> > Hi,
> >
> > For example,
> >
> > natural_nums <- 1:10
> > even_nums <- seq(2,10, by = 2)
> > types <- c("natural_nums", "even_nums")
> >
> > What functions can be performed on types[1] to turn it into a variable
> > name
> > and not a string ?
> >
> > [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > 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.
> --
> Simon Blomberg, BSc (Hons), PhD, MAppStat.
> Lecturer and Consultant Statistician
> Faculty of Biological and Chemical Sciences
> The University of Queensland
> St. Lucia Queensland 4072
> Australia
> Room 320 Goddard Building (8)
> T: +61 7 3365 2506
> http://www.uq.edu.au/~uqsblomb
> email: S.Blomberg1_at_uq.edu.au
>
> Policies:
> 1. I will NOT analyse your data for you.
> 2. Your deadline is your problem.
>
> The combination of some data and an aching desire for
> an answer does not ensure that a reasonable answer can
> be extracted from a given body of data. - John Tukey.
>
>

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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. Received on Fri 14 Mar 2008 - 08:25:50 GMT

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