[R] Pattern match in R

[(Ted Harding)]

On 30-Sep-08 14:36:04, bioinformatics_guy wrote:
> I want to make sure this piece of code I wrote is doing what
> I want it to do.
> 
> ll<-function(string)
> {
>       grep(string,dir(),value=T)
> }
> 
> subdir = ll("Coverage_[1-9][0-9]$")
> 
> I basically wrote a little function that would grab all the
> files of form Coverage_[0-99]
> 
> The way I wrote it, will it grab Coverage_5 or does it have to have 2
> numbers (10-99)?

I think you want "Coverage_[1-9]*[0-9]$", since your form will
only
match "Coverage_mn" where m is one of 1-9 and n is one of 0-9.
The "*" means "zero or any number of ... ".

Example (command-line grep in Linux):

grep 'Coverage_[1-9]*[0-9]$' << EOT
> Coverage
> Coverage_5
> Coverage_01
> Coverage_19
> Coverage_19q
> EOT
Coverage_5
Coverage_19

Note that this does not catch "Coverage_01" because "[1-9]"
does not include "0". Use "[0-9]" here as well if you need this.

Hoping this helps,
Ted.


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Date: 30-Sep-08                                       Time: 16:43:01
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