[R] sorting factor levels by data frequency of levels

[Dimitris Rizopoulos]

one way is the following:

tb <- table(state)
statefac <- factor(state,
    levels = names(tb[order(tb, decreasing = TRUE)]))


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
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Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: "Shoaaib Mehmood" <shoaaib at gmail.com>
To: <r-help at stat.math.ethz.ch>; <r-help at r-project.org>
Sent: Friday, November 16, 2007 11:21 AM
Subject: [R] sorting factor levels by data frequency of levels


> using an example from r online help
>
>> state <- c("tas", "sa", "qld", "nsw", "nsw", "nt", "wa", "wa",
>    "qld", "vic", "nsw", "vic", "qld", "qld", "sa", "tas",
>    "sa", "nt", "wa", "vic", "qld", "nsw", "nsw", "wa",
>    "sa", "act", "nsw", "vic", "vic", "act")
>>statefac<-factor(state)
>
> now if i use levels function to print factor levels they are shown
> sorted by alphabetical order. the output is shown below
>
>>levels(statefac)
> [1] "act" "nsw" "nt" "qld" "sa" "tas" "vic" "wa"
>
> I WANT THE FACTOR LEVELS TO BE SORTED IN ORDER OF DESCENDING DATA
> FREQUENCY IN EACH LEVEL. IN OTHER WORDS I WANT THE LEVEL WHICH HAS 
> THE
> HIGHEST FREQUENCY IN STATE TO APPEAR FIRST, FOLLOWED BY ONE WHICH 
> HAS
> THE SECOND HIGHEST FREQUENCY AND SO ON.
>
> Any help will be appreciated
>
>
> -- 
> Regards,
> Rana Shoaaib Mehmood
>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 


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