[R] Relevel dynamically

R. Michael Weylandt michael.weylandt at gmail.com
Mon Jan 16 16:00:19 CET 2012


If I understand you right: you have an "overall" order you want to
always keep, but need to get only those elements that show up in your
df while keeping them in the right order. I think this works:

factor(df$name, levels = intersect(OVERALL, df$name))

Michael

On Mon, Jan 16, 2012 at 8:53 AM, mails <mails00000 at gmail.com> wrote:
> Dear list,
>
>
> I am running R code which produces a data.frame with variable rows. For
> plotting purposes I need to relevel
> the column called "names" but since the dimension of the data.frame can vary
> I do not know how to dynamically
> revel the data.frame.
>
> Here is an example data.frame called df to illustrate what I try to achieve:
>
>> df <- data.frame(cbind(c("a","b","c","d","e"), c(5,6,4,8,9)))
>> colnames(df) <- c("name", "value")
>> df
>  name value
> 1    a     5
> 2    b     6
> 3    c     4
> 4    d     8
> 5    e     9
>
> Now the releveling:
> df$name <- factor(df$name, levels=c("b","d","c","e","a"))
>
> That was easy. But the plotting goes wrong when the data.frame has less
> rows:
>
>> df
>  name value
> 1    a     5
> 4    d     8
> 5    e     9
>
> Now my script runs the same line again:
> df$name <- factor(df$name, levels=c("b","d","c","e","a"))
>
> R does not throw any errors, however, lattice does not plot the results
> correctly. So I dynamically create
> a line which does the following: df$name <- factor(df$name,
> levels=c("d","e","a"))
>
>
> Thanks for any advice in advance!
>
> Cheers
>
>
>
>
> --
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>
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