[R] sort a data.frame

[Nikhil Kaza]

Try this.

dd[order(gsub("chr","",dd$b)),]

You need regular expressions if chr is not the only characterstring  
that is prepended to the numbers.
look for
?strsplit


Nikhil Kaza
University of North Carolina
nikhil.list at gmail.com



On May 20, 2010, at 8:28 AM, Yuan Jian wrote:

> Hello,
>
> I have a dataframe:
> dd <- data.frame(b = c("chr2", "chr1", "chr15", "chr13"),
>       x = c("A", "D", "A", "C"), y = c(8, 3, 9, 9),
>        z = c(1, 1, 1, 2))
>
>> dd
>       b x y z
> 1  chr2 A 8 1
> 2  chr1 D 3 1
> 3 chr15 A 9 1
> 4 chr13 C 9 2
>
> Now I want to sort them according column "b", but only its number is  
> considered:
>       b x y z
> 1  chr1 D 3 1
> 2 chr13 C 9 2
> 3 chr15 A 9 1
> 4  chr2 A 8 1
>
> thanks
> jian
>
>
>
>
>
>
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>
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