[R] Sorting a data frame when you don't know the columns

[michael watson (IAH-C)]

Thanks guys, sorted now :)

________________________________

From: Peter Dalgaard [mailto:P.Dalgaard at biostat.ku.dk]
Sent: Tue 28/11/2006 11:05 AM
To: Gabor Grothendieck
Cc: michael watson (IAH-C); r-help at stat.math.ethz.ch
Subject: Re: [R] Sorting a data frame when you don't know the columns



Gabor Grothendieck wrote:
> DF <- data.frame(a = c(3, 4, 2, 3, 2, 4, 2), b = 7:1))
> DF[do.call(order, DF),]
>
> will sort on all the columns.
... and you can use

DF[do.call(order, DF[names]),]

if you have the column names in a character vector.

>
> On 11/28/06, michael watson (IAH-C) <michael.watson at bbsrc.ac.uk> wrote:
>> Hi
>>
>> Sorry to ask such a well oiled question, but even with multiple google hits I don't think this has been answered very well.
>>
>> It's all well and good doing a sort of a data frame on multiple columns when you know in advance which columns you want to sort on, but what about when the names of the columns you wish to sort on are in a vector?
>>
>> At the minute I'm messing about with paste() to form a string that works for order() and then calling do.call().  Is this really the best way of doing it?
>>
>> Thanks
>> Mick
>>
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>>
>
> ______________________________________________
> 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
> and provide commented, minimal, self-contained, reproducible code.

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