Hi, One more solution:
new<-"AAAABBBBBABBBABB" resAB<-count(unlist(strsplit(gsub("AB",1,new),""))==1)[2,] resAB # x freq #2 TRUE 3 resBA<-count(unlist(strsplit(gsub("BA",2,new),""))==2)[2,] resBA # x freq #2 TRUE 2 new1<-c("ABABAAABABAAAABABABBA") resAB<-count(unlist(strsplit(gsub("AB",1,new1),""))==1)[2,] resAB # x freq #2 TRUE 7 resBA<-count(unlist(strsplit(gsub("BA",2,new1),""))==2)[2,] resBA # x freq #2 TRUE 7 A.K. ----- Original Message ----- From: rnewbie565 <amy.jacobs...@gmail.com> To: r-help@r-project.org Cc: Sent: Thursday, August 2, 2012 5:27 PM Subject: [R] text search in r I am trying to count the number of times that the characters in a string change For example- new=c(AAAABBBBBABBBABB) I want to find the number of times that B changes to A and the number of times that A changes to B. I tried the grep command but I only figured out the positions of when B changes to A when I only need the number of times it occurs. -- View this message in context: http://r.789695.n4.nabble.com/text-search-in-r-tp4638961.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org 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. ______________________________________________ R-help@r-project.org 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.