Saya tidak sepenuhnya yakin apa yang menyebabkan ini, jadi inilah WE paling minimal yang bisa saya temukan
library(data.table) # Tested on v 1.9.7
dt <- data.table( origin = c("A", "A", "A", "A", "A", "A", "B", "B", "A", "A", "C", "C", "B", "B", "B", "B", "B", "C", "C", "B", "A", "C", "C", "C", "C", "C", "A", "A", "C", "C", "B", "B"),
destination = c("A", "A", "A", "A", "B", "B", "A", "A", "C", "C", "A", "A", "B", "B", "B", "C", "C", "B", "B", "A", "B", "C", "C", "C", "A", "A", "C", "C", "B", "B", "C", "C"),
points_in_dest = c(5, 5, 5, 5, 4, 4, 5, 5, 3, 3, 5, 5, 4, 4, 4, 3, 3, 4, 4, 5, 4, 3, 3, 3, 5,5, 3, 3, 4, 4, 3, 3),
depart_time = c(7, 8, 16, 18, 7, 8, 16, 18, 7, 8, 16, 18, 7, 8, 16, 7, 8, 16, 18, 8, 16, 7, 8, 18, 7, 8, 16, 18, 7, 8, 16, 18),
travel_time = c(0, 0, 0, 0, 70, 10, 70, 10, 10, 10, 70, 70, 0, 0, 0, 70, 10, 10, 70, 70, 10, 0, 0, 0, 10, 70, 10, 70, 10, 70, 70, 10) )
dt[ depart_time<=8 & travel_time < 60, condition1 := TRUE]
dt[ depart_time>=16 & travel_time < 60, condition2 := TRUE]
setkey(dt, origin, destination)
res <- unique(dt[(condition1)])[unique(dt[(condition2)]),
on = c(destination = "origin", origin = "destination"),
nomatch = 0L]
res[, .(points = sum(points_in_dest)), keyby = origin]
# origin points
#1: A 5
#2: A 4
#3: B 4
#4: B 3
#5: C 5
#6: C 4
#7: C 3
Seperti yang Anda lihat, by
tidak berfungsi sebagaimana mestinya dan semua baris dikembalikan. Ini jelas merupakan masalah kunci karena perbaikan berikut ini:
setattr(res, "sorted", NULL)
res[, .(points = sum(points_in_dest)), keyby = origin]
# origin points
#1: A 9
#2: B 7
#3: C 12
Atau, sebagai alternatif, mengklasifikasikan origin
ke suatu faktor
res[, .(points = sum(points_in_dest)), keyby = factor(origin)]
# factor points
#1: A 9
#2: B 7
#3: C 12
Ini diambil dari pertanyaan SO ini http://stackoverflow.com/questions/37239649/aggregate-data-table-based-on-condition-in-another-row
Contoh yang sangat bagus. Akan memperbaiki. Terima kasih.
harus dikatakan, itu cara kreatif untuk mengeja fungsionalitas!
Tetap....
Komentar yang paling membantu
Contoh yang sangat bagus. Akan memperbaiki. Terima kasih.