how to count number of occurrences

Nordlund, Dan (DSHS/RDA) · 2011-11-04T07:52:58Z

> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r- > project.org] On Behalf Of uka > Sent: Thursday, November 03, 2011 4:10 PM > To: r-help at r-project.org > Subject: Re: [R] how to count number of occurrences > > This was very helpful. Thank you very much. Just one question, I notice > that > it does not count the number of X's before the first Y. I want the > result be > 1 4 0 0 0 5 0 0 0 0. I tried combining this output with the first value > o

Nordlund, Dan (DSHS/RDA)

Fri, Nov 4, 2011 12:52 AM

You should really provide the relevant context from previous posts so that potential helpers don't need to go looking for it.  That being said, you could try something like

samp <- c("X", "Y", "X", "X", "X", "X", "Y", "Y", "Y", "Y", "X", "X", "X", "X", "X", "Y", "Y", "Y", "Y", "Y")
diff(which(c('Y', samp)=='Y'))-1 


Hope this is helpful,

Dan

Daniel J. Nordlund
Washington State Department of Social and Health Services
Planning, Performance, and Accountability
Research and Data Analysis Division
Olympia, WA 98504-5204

Thread (6 messages)

Sl K how to count number of occurrences Nov 2 Sarah Goslee how to count number of occurrences Nov 2 William Dunlap how to count number of occurrences Nov 2 David Winsemius how to count number of occurrences Nov 2 uka how to count number of occurrences Nov 3 Nordlund, Dan (DSHS/RDA) how to count number of occurrences Nov 4