[R] Regular Expressions

[Dimitris Rizopoulos]

try this:

S <- c("World_is_beautiful", "one_two_three_four","My_book")

sapply(strsplit(S, "_"), tail, n = 2)[1, ]
# or
sapply(strsplit(S, "_"), function(x) x[length(x) - 1])


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: "Shubha Vishwanath Karanth" <shubhak at ambaresearch.com>
To: <r-help at stat.math.ethz.ch>
Sent: Tuesday, May 13, 2008 11:02 AM
Subject: [R] Regular Expressions


Hi R,



Again struck with regular expressions...



Suppose,



S=c("World_is_beautiful", "one_two_three_four","My_book")



I need to extract the last but one element of the strings. So, my 
output should look like:

Ans=c("is","three","My")



gsub() can do this...but wondering how do I give the regular 
expression....







Shubha Karanth | Amba Research

Ph +91 80 3980 8031 | Mob +91 94 4886 4510

Bangalore * Colombo * London * New York * San José * Singapore * 
www.ambaresearch.com



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