I have the following dt
set.seed(12048)
CC <- c("A", "A", "A", "B", "B", "C", "A", "B")
PO <- c("PO1", "PO2", "PO3", "PO4", "PO5", "PO6", "PO7", "PO8")
Rating <- c(1, 3, 3, 2, 4, 2, 1, 2)
dt <- data.table(CC, PO, Rating)
This shows up like so:
CC PO Rating
1: A PO1 1
2: A PO2 3
3: A PO3 3
4: B PO4 2
5: B PO5 4
6: C PO6 2
7: A PO7 1
8: B PO8 2
My intention is to have a table like so:
dept Rating1 Rating2 Rating3 Rating4
1: A 2 0 2 0
2: B 0 2 0 1
3: C 0 1 0 0
I know about 'melt' family of functions, but is there a Data table way of doing this?
I am trying something around this but apparently it is not correct.
dt[,.(.N,Rating1=nrow(Rating==1),Rating2=nrow(Rating==2),Rating3=nrow(Rating==3),Rating4=nrow(Rating==4)), by=.(CC, Rating)]
Any help is appreciated
