Re: [Rd] Getting ordered factor levels from C

From: Mark Lilback <mlilback_at_stat.wvu.edu>
Date: Wed, 24 Oct 2012 17:19:44 -0400

I was banging my head for an hour on this. I just pasted the code into an email and see that I was getting the contents of the SEXP for the factor, not the one returned by getAttrib. Sorry for the waste of time.

On Oct 24, 2012, at 4:16 PM, Simon Urbanek <simon.urbanek_at_r-project.org> wrote:

> 
> On Oct 24, 2012, at 2:14 PM, Mark Lilback wrote:
> 

>> I'm working on an R package in C and can't seem to get the same level information about a factor that the R console displays.
>>
>> If I define a factor as:
>>
>> lvls <- factor(c('red','blue','blue','green','red'), c('blue','green','red'), ordered=TRUE)
>>
>> When I get the "levels" attribute in C, I get back the the first vector, not the second.
> 
> What are you using in C? AFAICS it works just fine:
> 

>> f=cfunction(c(foo="factor"), "return getAttrib(foo, R_LevelsSymbol);")
>> f(lvls)
> [1] "blue" "green" "red"
>
-- 
Mark Lilback
West Virginia University Department of Statistics
mlilback_at_stat.wvu.edu

______________________________________________
R-devel_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
Received on Wed 24 Oct 2012 - 21:21:54 GMT

This quarter's messages: by month, or sorted: [ by date ] [ by thread ] [ by subject ] [ by author ]

All messages

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Thu 25 Oct 2012 - 11:10:49 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-devel. Please read the posting guide before posting to the list.

list of date sections of archive