[R] Factor Madness

[Tony Plate]

Whoops, it looks like there's a typo in ?cbind (R version 2.6.0 Patched 
(2007-10-11 r43143)), and I blindly copied it into my message.

That should read (emphasis added):

"and convert character columns to factors unless stringsAsFactors = 
***FALSE***"

Here's an example:

 > x <- data.frame(X=1:3)
 > sapply(cbind(x, letters[1:3]), class)
            X letters[1:3]
    "integer"     "factor"
 > sapply(cbind(x, letters[1:3], stringsAsFactors=FALSE), class)
            X letters[1:3]
    "integer"  "character"
 >

Thanks to Mark Leeds for pointing that out to me in a private message!

(I see this still in the source at 
https://svn.r-project.org/R/trunk/src/library/base/man/cbind.Rd -- is that 
the right place to look for the latest source to make sure it hasn't been 
fixed already?)

-- Tony Plate


Tony Plate wrote:
>  From ?cbind:
> 
> Data frame methods
> The cbind data frame method is just a wrapper for data.frame(..., 
> check.names = FALSE). This means that it will split matrix columns in data 
> frame arguments, and convert character columns to factors unless 
> stringsAsFactors = TRUE is passed.
> 
> (I'm guessing 'spectrum' is a data.frame before the code fragment you've shown)
> 
> hope this helps,
> 
> Tony Plate
> 
> Johannes Graumann wrote:
>> Why is class(spectrum[["Ion"]]) after this "factor"?
>>
>> spectrum <- cbind(spectrum,Ion=rep("",
>> nrow(spectrum)),Deviation.AMU=rep(0.0, nrow(spectrum)))
>>
>> slowly going crazy ...
>>
>> Joh
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>