[R] converting the string columns in a data.frame to factors?

[Ivan Calandra]

Hi John,

Use factor():
aframe2$x <- factor(aframe2$x)

Or, for all columns at once (there might be an easier solution):
aframe2 <- as.data.frame(lapply(aframe1, factor))

see ?factor

HTH,
Ivan

Le 2/28/2011 18:13, John Edwards a écrit :
> Dear All,
>
> I'm not sure if I understand the parameter stringsAsFactors correctly. I'm
> trying to convert the string columns in aframe1 to factors. But it
> seems stringsAsFactors=T in as.data.frame() doesn't do anything. Could
> anybody let know what is the correct way to converting strings to factors?
>
>> aframe1=data.frame(x=LETTERS[1:10], y=LETTERS[1:10], stringsAsFactors=F)
>> aframe2=as.data.frame(aframe1, stringsAsFactors=T)
>>
>> str(aframe1)
> 'data.frame': 10 obs. of  2 variables:
>   $ x: chr  "A" "B" "C" "D" ...
>   $ y: chr  "A" "B" "C" "D" ...
>> str(aframe2)
> 'data.frame': 10 obs. of  2 variables:
>   $ x: chr  "A" "B" "C" "D" ...
>   $ y: chr  "A" "B" "C" "D" ...
> Thanks,
> John
>
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>
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-- 
Ivan CALANDRA
PhD Student
University of Hamburg
Biozentrum Grindel und Zoologisches Museum
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+49(0)40 42838 6231
ivan.calandra at uni-hamburg.de

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