[R] Simple order() data frame question.

[John Kane]

Ah, this never would have occured to me.  It's rather obvious now but of course, I'll forget it again.  Note to self: Put it in the cribsheet.

Thanks very mcuy

--- On Thu, 5/12/11, Nick Sabbe <nick.sabbe at ugent.be> wrote:

> From: Nick Sabbe <nick.sabbe at ugent.be>
> Subject: RE: [R] Simple order()  data frame question.
> To: "'John Kane'" <jrkrideau at yahoo.ca>, "'R R-help'" <r-help at stat.math.ethz.ch>
> Received: Thursday, May 12, 2011, 8:50 AM
> Try
> (df1[order(-df1[,2]),])
> Adding the minus within the [ leaves out the column (in
> this case column 2).
> See ?"[".
> 
> HTH.
> 
> 
> Nick Sabbe
> --
> ping: nick.sabbe at ugent.be
> link: http://biomath.ugent.be
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> ring: 09/264.59.36
> 
> -- Do Not Disapprove
> 
> 
> 
> 
> -----Original Message-----
> From: r-help-bounces at r-project.org
> [mailto:r-help-bounces at r-project.org]
> On
> Behalf Of John Kane
> Sent: donderdag 12 mei 2011 14:33
> To: R R-help
> Subject: [R] Simple order() data frame question.
> 
> Clearly, I don't understand what order() is doing and as
> ususl the help for
> order seems to only confuse me more. For some reason I just
> don't follow the
> examples there. I must be missing something about the data
> frame sort there
> but what?
> 
> I originally wanted to  reverse-order my data frame
> df1 (see below) by aa (a
> factor) but since this was not working I decided to
> simplify and order by bb
> to see what was haqppening!!
> 
> I'm obviously doing something stupid but what? 
> 
> (df1 <- data.frame(aa=letters[1:10],
>      bb=rnorm(10)))
> # Order in acending order by bb
> (df1[order(df1[,2]),] ) # seems to work fine
> 
> # Order in decending order by bb.
> (df1[order(df1[,-2]),])  # does not seem to work
> 
> 
> ===============================================================
>  sessionInfo()
> R version 2.13.0 (2011-04-13)
> Platform: i386-pc-mingw32/i386 (32-bit)
> 
> locale:
> [1] LC_COLLATE=English_Canada.1252 
> LC_CTYPE=English_Canada.1252
> LC_MONETARY=English_Canada.1252
> [4] LC_NUMERIC=C           
>        
> LC_TIME=English_Canada.1252    
> 
> attached base packages:
>  [1] grid      grDevices datasets 
> splines   graphics  stats 
>    tcltk
> utils 
>    methods   base 
>    
> 
> other attached packages:
> [1]
> ggplot2_0.8.9   proto_0.3-9.2   reshape_0.8.4   plyr_1.5.2
> svSocket_0.9-51 TinnR_1.0.3 
>    R2HTML_2.2     
> [8] Hmisc_3.8-3     survival_2.36-9
> 
> loaded via a namespace (and not attached):
> [1] cluster_1.13.3  lattice_0.19-26
> svMisc_0.9-61   tools_2.13.0   
> >
> 
> ______________________________________________
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