[R] Calculating column differences

[Gerrit Eichner]

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 using math.uni-giessen.de   Justus-Liebig-University Giessen
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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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