[R] Group by and duplicate a value/dplyr

[Gerrit Eichner]

Homework?

Try maybe

mutate(MinValue = min(Value[Value != 0]) )

or

mutate(MinValue = sort(unique(Value))[2])

  Hth  --  Gerrit

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Dr. Gerrit Eichner                   Mathematical Institute, Room 212
gerrit.eichner using 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 11.05.2021 um 13:11 schrieb Elahe chalabi via R-help:
> Hi all,
> 
> I have the following data frame
> 
> 
> dput(df)
>      structure(list(Department = c("A", "A", "A", "A", "A", "A", "A",
> "A", "B", "B", "B", "B", "B", "B", "B", "B"), Class = c(1L, 1L,
> 1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L), Value = c(0L,
> 100L, 800L, 800L, 0L, 300L, 1200L, 1200L, 0L, 0L, 400L, 400L,
> 200L, 800L, 1200L, 1200L)), class = "data.frame", row.names = c(NA,
> -16L))
> 
> 
> I would like to group by "Department" and "Class" and repeat the minimum value of "Valule" excluding zeros or get the second minimum value. The desired output is:
> 
> 
>      dput(df)
>      structure(list(Department = c("A", "A", "A", "A", "A", "A", "A",
> "A", "B", "B", "B", "B", "B", "B", "B", "B"), Class = c(1L, 1L,
> 1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L), Value = c(0L,
> 100L, 800L, 800L, 0L, 300L, 1200L, 1200L, 0L, 0L, 400L, 400L,
> 200L, 800L, 1200L, 1200L), MinValue = c(100L, 100L, 100L, 100L,
> 300L, 300L, 300L, 300L, 400L, 400L, 400L, 400L, 200L, 200L, 200L,
> 200L)), class = "data.frame", row.names = c(NA, -16L))
> 
>     
> how should I change the following dplyr to give me the desired output?
> 
> 
>     df <-
>    df %>%
>    group_by(Department,Class) %>%
>    mutate(MinValue=min(Value) )
> 
> 
> Thanks for any help.
> Elahe
> 
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