"Keep the first values" is imprecise, but mixing an absolute value with a bunch of differences doesn't usually work out well. I frequently choose among
x <- sample( 10 ) dxright <- c( 0, diff(x) ) dxleft <- c( diff(x), 0 ) for calculation purposes depending on my needs. -- Sent from my phone. Please excuse my brevity. On March 4, 2016 3:28:08 AM PST, Olivier Crouzet <olivier.crou...@univ-nantes.fr> wrote: >Hi, > >(1) You should provide a minimal working example; > >(2) But anyway, does... > >x = sample(10) >c(x[1],diff(x)) > >... do what you want? > >Olivier. > > >On Fri, 4 Mar 2016 >13:22:07 +0200 catalin roibu <catalinro...@gmail.com> wrote: > >> Dear all! >> >> I want to calculate difference between successive values (cumulative >> values) with R. I used diff function, but I want to keep the first >> values. >> >> Please help me to solve this problem! >> >> Thank you! >> >> Best regards! >> >> CR >> >> -- >> >> - >> - >> Catalin-Constantin ROIBU >> >> Lecturer PhD, Forestry engineer >> Forestry Faculty of Suceava >> Str. Universitatii no. 13, Suceava, 720229, Romania >> office phone +4 0230 52 29 78, ext. 531 >> mobile phone +4 0745 53 18 01 >> FAX: +4 0230 52 16 64 >> silvic.usv.ro <http://www.usv.ro/> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. > >-- > Olivier Crouzet, PhD > Laboratoire de Linguistique de Nantes -- UMR6310 > CNRS / Université de Nantes > Chemin de la Censive du Tertre -- BP 81227 > 44312 Nantes cedex 3 > France > > http://www.lling.univ-nantes.fr/ > >______________________________________________ >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >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. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.