[R] sort a data frame according to roman characters

[Peter Dalgaard]

Luis Ridao Cruz wrote:
> R-help,
>
> I have a data frame with one column containing roman numbers
> The data are not sorted as : I    II   III  IV   V    VI   VII  VIII IX
>   X    XI   XII  XIII XIV  XV
>
> Using data[order(data$Roman),] does not do the job.
>
> How can this be done?
>
>   

Someone went there before you (and me):

library(utils)
data[order(as.roman(data$Roman)),]

(possibly ....as.character(data$Roman).... if it has been read as a factor)

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