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

From: Ivan Calandra <ivan.calandra_at_uni-hamburg.de>
Date: Mon, 28 Feb 2011 18:22:58 +0100

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
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University of Hamburg
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Abt. Säugetiere
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D-20146 Hamburg, GERMANY
+49(0)40 42838 6231
ivan.calandra_at_uni-hamburg.de

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