[R] difference between successive values

[catalin roibu]

I mean the first row value

În Vin, 4 mar. 2016, 16:15 Jeff Newmiller, <jdnewmil at dcn.davis.ca.us> a
scris:

> "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.crouzet at 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 <catalinroibu at 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 at 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 at 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 at 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.

-- 

-
-
Catalin-Constantin ROIBU
​
Lecturer PhD, Forestry engineer
​
Forestry Faculty of Suceava
Str. Universitatii no. 13, Suceava, 720229,
office phone     +4 0230 52 29 78, ext. 531
mobile phone   +4 0745 53 18 01
                       +4 0766 71 76 58
FAX:                +4 0230 52 16 64
silvic.usv.ro <http://www.usv.ro/>

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