[R] having problems with factor()

[Rainer Hurling]

I am afraid the above example will not work. In original dataset of 
Jabez Wilson numerical range is from 0..7.

So try this one:

df<-as.factor(c("0","I","II","III","IV","V","VI","VII")[df$area+1])

Hope this is what you want,
Rainer


Henrique Dallazuanna schrieb:
> Hi,
> 
> df
>     ht area
> 1  320    3
> 2  410    4
> 3  230    2
> 4  360    3
> 5  126    1
> 6  280    2
> 7  260    2
> 8  280    2
> 9  280    2
> 10 260    2
> 
> df$area <- as.factor(df$area)
> levels(df$area) <- c("I", "II", "III", "IV")
 >
 >
 > On 10/08/07, Jabez Wilson <jabezwuk at yahoo.co.uk> wrote:
 >> Dear R Help,
 >> I have a set of data of heights of trees described by area that they 
 >> are in. The areas are numerical (0 to 7).
 >>
 >>     ht    area
 >> 1   320   3
 >> 2   410   4
 >> 3   230   2
 >> 4   360   3
 >> 5   126   1
 >> 6   280   2
 >> 7   260   2
 >> 8   280   2
 >> 9   280   2
 >> 10  260   2
 >> .......
 >> 180 450   4
 >> 181  90   1
 >> 182 120   1
 >> 183 440   4
 >> 184 210   2
 >> 185 330   3
 >> 186 210   2
 >> 187 100   1
 >> 188   0   0
 >>
 >> I want to convert the area column values to factors, to do an anova.
 >> However, if I use:
 >>
 >> df$areaf <- factor(df$area,
 >> labels=c("0","I","II","III","IV","V","VI","VII"))
 >>
 >> it gives the following message:
 >>
 >> Error in factor(df$area, labels = c("0", "I", "II", "III", "IV", "V",
 >> "VI",  :
 >>         invalid labels; length 8 should be 1 or 7
 >>
 >> Can anyone help?
 >>
 >> Jabez