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]]

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

eval(types[[1]])

eval(types[[2]])

assign("natural_nums", 1:10)
natural_nums

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
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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]]