R help - Sep 2005 - Sort a data frame with respect to more than one variable

Dear All,
 
How can I sort a data frame with respect to more than one  variable?
 
I know that for one variable X  one may use:   df[order(df$X), ] where df is 
the data frame containing X.
 
Many thanks,
 
Bernard
 
 

		
---------------------------------


	[[alternative HTML version deleted]]

Marc Bernard a ??crit :
> I know that for one variable X  one may use:   
 > df[order(df$X), ] where df is  the data frame containing X.

probably not optimal, but simply why not ?
dfX  = df[order(df$X), ];
dfXY  = dfX[order(dfX$Y), ];
hih

Le 21.09.2005 10:54, Marc Bernard a ??crit :
>Dear All,
> 
>How can I sort a data frame with respect to more than one  variable?
> 
>I know that for one variable X  one may use:   df[order(df$X), ] where df is
the data frame containing X.
> 
>Many thanks,
> 
>Bernard
>  
>
You already know the answer of that question. order() accepts more than 
one variable.

x <- rep(rbinom(5,size=4,prob=.5), 6)
y <- rnorm(30)
cbind(x,y)[ order(x,y) , ]

Romain

-- 
visit the R Graph Gallery : http://addictedtor.free.fr/graphiques
~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~
~~~~~~      Romain FRANCOIS - http://addictedtor.free.fr         ~~~~~~
~~~~        Etudiant  ISUP - CS3 - Industrie et Services           ~~~~
~~                http://www.isup.cicrp.jussieu.fr/                  ~~
~~~~           Stagiaire INRIA Futurs - Equipe SELECT              ~~~~
~~~~~~   http://www.inria.fr/recherche/equipes/select.fr.html    ~~~~~~
~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~

if you need nested sorting then you can still use order(), e.g., in a 
longitudinal setting you may want to sort your data.frame with respect 
to subject's id and time within subject then use,

df[order(df$id, df$time), ]

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: +32/16/336899
Fax: +32/16/337015
Web: http://www.med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: "Marc Bernard" <bernarduse1 at yahoo.fr>
To: <r-help at stat.math.ethz.ch>
Sent: Wednesday, September 21, 2005 10:54 AM
Subject: [R] Sort a data frame with respect to more than one variable

> Dear All,
>
> How can I sort a data frame with respect to more than one  variable?
>
> I know that for one variable X  one may use:   df[order(df$X), ] 
> where df is  the data frame containing X.
>
> Many thanks,
>
> Bernard
>
>
>
>
> ---------------------------------
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
> 

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm