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rdplyrfiltermutate

how to find the difference from each group-value from the maximum within one group in R?

I have the following data:

data <- data.frame(id_pers=c(1, 2, 3, 4, 5),
                       Birthyear=c(2018, 2009, 2008, 2000, 1998,2005),
                       family=c(Elliot, Elliot, Elliot, Gerrard, Gerrard,Gerrard)

I want to find the maximal difference (in birthyear) in each family, that is the same for all the family-members in the following.

It should look like:

datanew <- data.frame(id_pers=c(1, 2, 3, 4, 5, 6),
                       Birthyear=c(2018, 2009, 2008, 2000, 1998, 2005),
                       family=c(Elliot, Elliot, Elliot, Gerrard, Gerrard, Gerrard),
                       maxdifference=c(10,10,10,7,7,7)
Solution

  • Obligatory base-r one-liner

    data$maxdifference = ave(data$Birthyear, data$family, FUN = \(years) max(years) - min(years))