[R] extract data for specific levels factor

Dennis Murphy
Tue, 25 Oct 2011 21:32:09 -0000

Are you trying to separate the substrings in cat? If so, one way is to
use the colsplit() function in the reshape2 package, something like
(untested since you did not provide a suitable data format with which
to work):

library('reshape2')
splitcat <- colsplit(mydata$cat, ' ', names = c('fat',
'bat', 'rat'))
moredat <- cbind(mydata, splitcat)

Other options that might pertain to your request include:

(i) subset(mydata, cat == 'por fol pec')
which you can use as a data argument inside ggplot2 - e.g.,

ggplot(subset(mydata, cat == 'por fol pec'), aes(x = age, y = ind)) +
   geom_point()

(ii) use faceting to get individual plots by factor level of cat - e.g.,
ggplot(mydata, aes(x = age, y = ind)) +
   geom_point() +
   facet_grid( ~ cat)

Hope that one of these is close to the bullseye...
Dennis


2011/10/25 Andr?s Arag?n <armandres at gmail.com>:
> Dear all,
>
> I'm trying to analyze data with the following structure:
>
> ind ? ? ? ? ?cat ? ? ? ? ? ?tx ? ? ?age
> 40.2 por fol peq ? ? vh ? ? ? ?35
> 41.9 por fol med ? ? vh ? ? ? ?35
> 68.9 por fol preov ? vh ? ? ? 35
> 71.5 por fol peq ? ? ?ser ? ? ? 37
> 67.5 ?por fol med ? ?ser ? ? ? 37
> 76.9 ?por fol preov ? ser ? ? 37
> 78.7 ?por fol peq ? ? ?otr ? ? ?37
> 78.3 ?por fol med ? ?otr ? ? ? 37
> 82.1 ?por fol preov ? otr ? ? ?37
> 83.9 ?por fol peq ? ? ?vh ? ? ? 37
> 80.6 ?por fol med ? ? ?vh ? ? ?37
> 76.1 ?por fol preov ? ? vh ? ? 37
> 86.9 ?por fol peq ? ? ? ?ser ? ? 35
> 97.7 ?por fol med ? ? ? ser ? ? 35
> 62.3 ?por fol preov ? ? ser ? ? 35
>
>
>
> I want to separate exclusively some of factor levels ?(?por fol peq?
> in the ?cat? colum). I am using ggplot2 ?and I only can plot all of
> factors, not separately. I did try ddply without success.
> Any help is welcome.
>
> Andr?s
>
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