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

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)

CodePudding user response：

Using tidyverse you can first group by family ID, then compute the distance via dist and take the maximum max.

library(tidyverse)
data <- data.frame(id_pers=c(1, 2, 3, 4, 5, 6),
                   Birthyear=c(2018, 2009, 2008, 2000, 1998,2005),
                   family=c(1, 1, 1, 2, 2,2))

data %>% dplyr::group_by(family) %>%
  dplyr::mutate(maxdifference = max(dist(Birthyear)))
# A tibble: 6 × 4
# Groups:   family [2]
  id_pers Birthyear family maxdifference
    <dbl>     <dbl>  <dbl>         <dbl>
1       1      2018      1            10
2       2      2009      1            10
3       3      2008      1            10
4       4      2000      2             7
5       5      1998      2             7
6       6      2005      2             7

CodePudding user response：

Another way is to take the difference of the range:

data %>% 
  group_by(family) %>% 
  mutate(maxdifference = diff(range(Birthyear)))

CodePudding user response：

data %>% group_by(family) %>% mutate(maxdifference = max(Birthyear)-min(Birthyear))

CodePudding user response：

Obligatory base-r one-liner

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