[R] max length of a factor variable

[Michael Bedward]

Hello Richard,

Since no one else has answered yet I'll venture a guess.

The following works on my little macbook...

x <- as.factor(sapply(letters[1:26], function(x) paste(rep(x, 100000),
collapse="")))

So each of the 26 factor levels in x has a string representation of
100,000 chars.  So I'm *guessing* the limit is only that imposed by
system memory.

Hopefully if that's wrong it will provoke someone to correct me :)

Michael

On 27 September 2010 19:15, Richard Mott <rmott at well.ox.ac.uk> wrote:
> Hi
>
> Is there a maximum length for the character string representing a level of a
> factor?  I have a set of several million variables, each a factor of length
> 19. Each factor level is a character string which in some cases can be many
> thousands of characters long.  I am trying to find out why my analysis fails
> - I just wanted to rule out the possibility that the internal factor
> conversion has a problem parsing long strings.
>
> Thanks
>
> Richard
> --
> ----------------------------------------------------
> Richard Mott       | Wellcome Trust Centre
> tel 01865 287588   | for Human Genetics
> fax 01865 287697   | Roosevelt Drive, Oxford OX3 7BN
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