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rdplyrsummarize

is there a simple way to add the dplyr summarize function result to every row?

The following is a simple version of my data:

sample dataset

I want to create a flag for each group if they at least have one item in Column1. I know I can do this in dplyr and then merge it with my original data but I was wondering if there is an easier way.

For example, I can do this: 

df_column <- df %>% filter(!is.na(Column1)) %>% group_by(Group)%>%
  summarize(n=n_distinct(Column1))

and then I can merge this with the original data and create a flag.

Solution

  • Without filtering, we can do this with mutate by creating a logical column based on the number of unique elements (n_distinct) in 'Column1' after groupingby 'Group'

    library(dplyr)
df %>%
     group_by(Group) %>%
     mutate(flag = n_distinct(Column1[!is.na(Column1)]) > 1)