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

Simon Blomberg s.blomberg1 at uq.edu.au
Fri Mar 14 05:54:21 CET 2008


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
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> 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]]
> 
> ______________________________________________
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> 
> ______________________________________________
> R-help at r-project.org 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.
-- 
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

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