我们可以创建一个“日期”序列(“v1”)的向量,split
该向量基于month
和year
。用于lapply
遍历列表并paste
从前四个观察中删除日期部分和日期(使用 提取substr
)。
library(lubridate)
v1 <- seq(as.Date("2004-01-01"), as.Date("2014-01-23"), by = "week")
lst <- split(v1, list(month(v1), year(v1)), drop=TRUE)
days <- substr(v1[1:4],9,10)
v2 <- unlist(lapply(lst, function(x) {
sprintf('%s%s', substr(x[1:4], 1,8), days)}), use.names=FALSE)
v2[1:8]
#[1] "2004-01-01" "2004-01-08" "2004-01-15" "2004-01-22" "2004-02-01"
#[6] "2004-02-08" "2004-02-15" "2004-02-22"
tail(v2,8)
#[1] "2013-12-01" "2013-12-08" "2013-12-15" "2013-12-22" "2014-01-01"
#[6] "2014-01-08" "2014-01-15" "2014-01-22"
或者另一种选择是
v1 <- seq(as.Date('2004-01-01'), length.out=4, by = 'week')
len <- 4*12*10 + 4
v2 <- rep(v1, len/4)
v3 <- do.call(paste, c(d1[do.call(order, d1),][1:484,-3], sep="-"))
res <- paste0(v3, sub('^\\d+-\\d+', '', v2))
head(res,8)
#[1] "2004-01-01" "2004-01-08" "2004-01-15" "2004-01-22" "2004-02-01"
#[6] "2004-02-08" "2004-02-15" "2004-02-22"
tail(res,8)
#[1] "2013-12-01" "2013-12-08" "2013-12-15" "2013-12-22" "2014-01-01"
#[6] "2014-01-08" "2014-01-15" "2014-01-22"