These two expressions might be what you are looking for -- sum (3 == x[c(-length(x),-(length(x)-1))]+x[c(-1,-length(x))]+x[c(-1,-2)]) sum (-3 == x[c(-length(x),-(length(x)-1))]+x[c(-1,-length(x))]+x[c(-1,-2)])
Ben Fairbank -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of vincent Sent: Monday, April 25, 2005 11:03 AM To: [email protected] Subject: [R] Proba( Ut+2=1 / ((Ut+1==1) && (Ut==1))) ? Dear all, First I apologize if my question is quite simple, but i'm very newbie with R. I have vectors of the form v = c(1,1,-1,-1,-1,1,1,1,1,-1,1) (longer than this one of course). The elements are only +1 or -1. I would like to calculate : - the frequencies of -1 occurences after 2 consecutives -1 - the frequencies of +1 occurences after 2 consecutives +1 It looks probably something like : Proba( Ut+2=1 / ((Ut+1==1) && (Ut==1))) could someone please give me a little hint about how i should/could begin to proceed ? Thanks (Thanks also to the R creators/contributors, this soft seems really great !) ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
