try something like this: vec <- c(1, 2, 1, NA, NA, 1, 2, NA, NA, NA, 3, 4, NA, NA)
out <- rle(is.na(vec)) table(out$lengths[out$values]) I hope it helps. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student 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: "Marie-Pierre Sylvestre" <[EMAIL PROTECTED]> To: <r-help@r-project.org> Sent: Thursday, October 11, 2007 3:47 PM Subject: [R] Identifying and characterizing strings of NA in a vector > Dear R users, > > I was wondering if someone could suggest a few lines of code for my > problem. > > I want to count the number and the length of strings of NA in a > vector. > For example: > > vec <- c(1, 2, 1, NA, NA, 1, 2, NA, NA, NA, 3, 4, NA, NA) > > has 2 strings of NA's of length 2 and 1 string of NA' of length 3. > > I can easily count the number of NA's per vector, but I am having a > hard > time counting the number and length of strings of NA's per vector > without relying heavily on loops. I will have to perform this task > for > many vectors. > > Can somebody help? > > many thanks, > > Marie-Pierre > > ______________________________________________ > 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. > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm ______________________________________________ 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.
