我正在尝试对data.table进行条件求和,并设法以杂乱的方式进行.我想知道是否可以更优雅地做到这一点？
考虑以下:
library(data.table)
stock_profile <- data.table(Pcode = c(123456L, 234567L, 345678L, 456789L, 567891L, 678912L, 789123L, 891234L, 912345L, 123456L, 234567L, 345678L, 456789L, 567891L, 678912L, 789123L, 891234L, 912345L),
Value = c(51.96, 89.64, 21.56, 56.04, 47.56,83.68, 42.21, 66.56, 62.72, 35.00, 3.40, 30.82, 59.83, 82.17, 14.02, 25.70, 81.38, 50.33),
Location = c("A", "A", "A", "A", "A", "A", "A", "A", "A","B", "B", "B", "B", "B", "B", "B", "B", "B"),
NoSales = c("","", "Y", "", "", "Y", "", "", "Y", "", "", "Y", "Y", "","", "", "Y", …