如何从年和周中确定月份？

Question

我想从周号和年号中获取月份名称：

date

Week    Year  
  52    2018
  20    2017
  47    2016

Answer 1

我们可以将pasteWeek day，week number和year一起转换为Date，然后使用format来获取月份名称。阅读?strptime格式选项

format(as.Date(paste(1, df$Week, df$Year), "%u %U %Y"), "%B")
#[1] "December" "May"      "November"

数据

df <- structure(list(Week = c(52L, 20L, 47L), Year = 2018:2016), 
     class = "data.frame", row.names = c(NA, -3L))