Message-ID: <08539cf0-1a49-1ac9-34e2-8006e8f90941@math.uni-giessen.de>
Date: 2021-03-24T16:52:38Z
From: Gerrit Eichner
Subject: Calculating column differences
In-Reply-To: <002b01d720cd$868cfc10$93a6f430$@sbcglobal.net>
Dear Jeff,
read diff's help page, and you'll find out
what is wrong with your expectation.
What do think diff(df$Score) should give for
the first element in df$Score??
Hth -- Gerrit
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Dr. Gerrit Eichner Mathematical Institute, Room 212
gerrit.eichner at math.uni-giessen.de Justus-Liebig-University Giessen
Tel: +49-(0)641-99-32104 Arndtstr. 2, 35392 Giessen, Germany
http://www.uni-giessen.de/eichner
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Am 24.03.2021 um 17:48 schrieb Jeff Reichman:
> r-help forum
>
>
>
> I'm trying to calculate the diff between two rows and them mutate the
> difference into a new column. I'm using the diff function but not giving me
> what I want.
>
>
>
> df <- data.frame(ID=1:5,Score=4*2:6)
>
>
>
> What a want where
>
> ID Score diff
>
> 1 1 8 8
>
> 2 2 12 4
>
> 3 3 16 4
>
> 4 4 20 4
>
> 5 5 24 4
>
>
>
> What I am getting
>
> ID Score diff
>
> 1 1 8 NA
>
> 2 2 12 4
>
> 3 3 16 4
>
> 4 4 20 4
>
> 5 5 24 4
>
>
>
> Jeff
>
>
>
>
> [[alternative HTML version deleted]]
>
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