Nice, thanks Petr :)
Ben Gillespie, Research Postgraduate o-------------------------------------------------------------------o School of Geography, University of Leeds, Leeds, LS2 9JT o-------------------------------------------------------------------o Tel: +44(0)113 34 33345 Mob: +44(0)770 868 7641 o-------------------------------o http://www.geog.leeds.ac.uk/ o-------------------------------------o @RiversBenG o--------------o ________________________________________ From: PIKAL Petr [petr.pi...@precheza.cz] Sent: 11 October 2013 14:06 To: Benjamin Gillespie; r-help@R-project.org Subject: RE: Possible loop/ if statement query Hi not sure if it is the most efficient and clever solution ifelse(b<7, NA, cumsum(c(0,diff(!(b<7)))==1)) Regards Petr > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Benjamin Gillespie > Sent: Thursday, October 10, 2013 12:39 AM > To: r-help@R-project.org > Subject: [R] Possible loop/ if statement query > > Dear r genii, > > I hope you can help. > > I have vector 'b': > > b=c((1:10),sort(1:9,decreasing=TRUE),(2:12),sort(6:11,decreasing=TRUE), > (7:13)) > > and, from 'b' I wish to create vector 'c': > > c=c( > NA,NA,NA,NA,NA,NA,1,1,1,1,1,1,1,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA, > 2,2,2,2,2,2,2,2,2,2,2,NA,3,3,3,3,3,3,3) > > The rules I want to use to create 'c' are: > > A numeric of equal to, or over 7 in 'b' needs to result in a numeric > (i.e. not NA) in 'c'; A numeric of less than 7 in 'b' needs to result > in "NA" in 'c'; Where 'groups' of numerics equal to, or over 7 in 'b' > are present (i.e. next to each other in the list), the numerics > produced in 'c' all need to be the same; Each 'group' of numerics in > 'b' must result in a unique numeric in 'c' (and, ideally, they should > run in sequence as in 'c' above (1,2,3...). > > If anyone has any idea where to start on this or can crack it I'll be > most grateful!! > > Many thanks in advance, > > Ben Gillespie, Research Postgraduate > o-------------------------------------------------------------------o > School of Geography, University of Leeds, Leeds, LS2 9JT o------------- > ------------------------------------------------------o > Tel: +44(0)113 34 33345 > Mob: +44(0)770 868 7641 > o-------------------------------o > http://www.geog.leeds.ac.uk/ > o-------------------------------------o > @RiversBenG > o--------------o > ______________________________________________ > 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.
