test <- data.frame('prod_id'= c("shoe", "shoe", "shoe", "shoe", "shoe", "shoe", "boat", "boat","boat","boat","boat","boat"),
'seller_id'= c("a", "b", "c", "d", "e", "f", "a","g", "h", "r", "q", "b"),
'Dich'= c(1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0),
'price' = c(120, 20, 10, 4, 3, 4, 30, 43, 56, 88, 75, 44)
)
test
prod_id seller_id Dich price
1 shoe a 1 120
2 shoe b 0 20
3 shoe c 0 10
4 shoe d 0 4
5 shoe e 0 …