[R] How to get assign an vector of words to associative array ?

[Duncan Murdoch]

On 15/04/2008 8:36 PM, Ng Stanley wrote:
> Hi,
> 
> How to get assign an vector of words to associative array ?
> 
>> a[["animal"]] <- c("dog", "cat")
> Error in a[["animal"]] <- c("dog", "cat") :
>   more elements supplied than there are to replace

R uses named lists as associative arrays, but the line above is not 
enough to create one.  You need

a <- list()
a[["animal"]] <- c("dog", "cat")

The error message you saw is probably because "a" already existed, and 
wasn't a list.

Duncan Murdoch