问题
我有一些数据集,这些数据已经按照以下结构进行处理和导出:
set.seed(123)
library(dplyr)
tb <- tibble(group = rep(c("A", "B"), each = 5),
wkday = rep(c("Mon", "Tue", "Wed", "Thu", "Fri"), times = 2),
sta = sample(-3:2, size = 10, replace = T),
mid = sta + 2,
fin = sta + 5)
问题