seq
在一个日期上获取日期序列
from <- as.Date( "2018-01-01" )
to <- as.Date( "2019-01-01" )
seq( from, to, by = "1 month")
# [1] "2018-01-01" "2018-02-01" "2018-03-01" "2018-04-01" "2018-05-01" "2018-06-01" "2018-07-01" "2018-08-01" "2018-09-01" "2018-10-01"
# [11] "2018-11-01" "2018-12-01" "2019-01-01"
seq( from, to, by = "1 quarter")
#[1] "2018-01-01" "2018-04-01" "2018-07-01" "2018-10-01" "2019-01-01"
seq( from, to, by = "6 month")
#[1] "2018-01-01" "2018-07-01" "2019-01-01"
seq( from, to, by = "1 year")
# [1] "2018-01-01" "2019-01-01"