[R] Splitting a categorical variable into multiple variables

[Claus O'Rourke]

Thanks Bert. I guess I was just wondering if there was a way to create
the new factors automatically without me having to hard code the level
names manually in my R code.

Rgds

Claus

On Fri, Aug 9, 2013 at 3:42 PM, Bert Gunter <gunter.berton at gene.com> wrote:
> ... or if you want to keep the unchanged levels the same:
>
> zz <- factor(ifelse( z %in% c("a", "b"),"d" ,levels(z)[z]))
>
> -- Bert
>
> On Fri, Aug 9, 2013 at 7:35 AM, Bert Gunter <bgunter at gene.com> wrote:
>> If I understand what you mean, just recode them.
>>
>> z <- factor(letters[1:3])
>> z
>> zz <- factor(ifelse( z %in% c("a", "b"),"d" ,z))
>> zz
>>
>> Cheers,
>> Bert
>>
>> On Fri, Aug 9, 2013 at 7:10 AM, Claus O'Rourke <claus.orourke at gmail.com> wrote:
>>> Hello R-Help,
>>> I have a variable with > 32 levels and I'd like to split this into two
>>> variables such that both new variables have >= 32 variables. This is
>>> to handle the limit of 32 level predictor variables in R's Random
>>> Forest implementation. Might someone be able to suggest an elegant way
>>> to do this? I've tried googling for this, but haven't hit the right
>>> search terms.
>>>
>>> Regards
>>>
>>> ______________________________________________
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>>
>>
>>
>> --
>>
>> Bert Gunter
>> Genentech Nonclinical Biostatistics
>>
>> Internal Contact Info:
>> Phone: 467-7374
>> Website:
>> http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm
>
>
>
> --
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
>
> Internal Contact Info:
> Phone: 467-7374
> Website:
> http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm