[R] max length of a factor variable

[Richard Mott]

Thanks

I eventually tracked down the problem to something unrelated to this 
question (one out of the millions of character strings happened to be 
"NA" by chance, which of course was parsed as a missing value, breaking 
the code a long way downstream.....)

Richard

On 28/09/2010 04:01, Michael Bedward wrote:
> 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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>>

-- 
----------------------------------------------------
Richard Mott       | Wellcome Trust Centre
tel 01865 287588   | for Human Genetics
fax 01865 287697   | Roosevelt Drive, Oxford OX3 7BN