I am not sure if the code below is what you are after out1 <- ds %>% group_by(id) %>% summarise(n = n()) %>% mutate(ncomb2 = choose(n,2)) such that > out1 # A tibble: 3 x 3 id n ncomb2 <dbl> <int> <dbl> 1 1 4 6 2 2 4 6 3 3 4 6 solved … Read more
Introduction Group_by and combinations are two powerful tools in the R programming language. They allow users to quickly and easily manipulate data and create meaningful insights. Group_by allows users to group data by one or more variables, while combinations allow users to create all possible combinations of a set of variables. In this article, we … Read more