[R] Re gular Expression help

[Peter Dalgaard]

Rajasekaramya wrote:
> hi there
> 
> I have a vector with a set of data.I just wanna seperate them based on the
> first p and q values metioned within the data.
> 
> [1] chr10p15.3 /// chr3q29 /// chr4q35 /// chr9q34.3
> [2] chr1q22-q24                                     
> [3] chr1q22-q24                                     
> [4] chr1pter-q24                                    
> [5] chr1pter-q24                                    
> [6] chr1pter-q24  
> 
> i used a regular expression [+q*] to match up the values but it matches q
> found anywhere i know i have written like that but i jus want it to match
> the first p or q values.
> 
> my result should be for q and 
> [2] chr1q22-q24                                      
> [3] chr1q22-q24  
> 
> for p
> [1] chr10p15.3 /// chr3q29 /// chr4q35 /// chr9q34.3
> [4] chr1pter-q24                                    
> [5] chr1pter-q24                                    
> [6] chr1pter-q24 
> 

Something like

sub("[^pq]*([pq]).*","\\1",x)

should get you the first p or q


-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
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