将季度年份转换为R中的季度末日期

Question

我使用as.Date(as.yearqtr(test[,1],format ="%qQ%Y"),frac =1)时遇到问题，但返回错误，并且四分之一年至今未更改。错误是：error in as.yearqtr(as.numeric(x)) (list) object cannot be coerced to type 'double'

这是我在R中的数据框。

TIME   VALUE
1Q2019  1
2Q2019  2
3Q2019  3
4Q2019  4

理想的输出是

TIME   VALUE
2019-03-31  1
2019-06-30  2
2019-09-30  3
2019-12-31  4

更新：实际数据是：

structure(list(...1=c("1Q2019","2Q2019","3Q2019","4Q2019"),...4 = c(0.001, 0.9, 0.873, 0.987)), .Names = c("...1","...4"), row.names = c(NA, -4L), class =c("tbl_df","tbl","data.frame"))

Answer 1

我们可以使用Zoo将其转换为Date并使用frac获得该季度的最后日期。我们使用一些RegEx重新以zoo的适当格式重新排列：

df$TIME=as.Date(as.yearqtr(gsub("(\\d)(Q)(\\d{1,})","\\3 Q\\1",df$TIME)),frac = 1)
 df
        TIME VALUE
1 2019-03-31     1
2 2019-06-30     2
3 2019-09-30     3
4 2019-12-31     4

数据：

df <-structure(list(TIME = structure(1:4, .Label = c("1Q2019", "2Q2019", 
"3Q2019", "4Q2019"), class = "factor"), VALUE = 1:4), class = "data.frame", row.names = c(NA, 
-4L))

Answer 2

这里是一个函数，将返回日期向量，给定输入向量的形式为1Q2019 ...

dateStrings <- c("1Q2019","2Q2019","3Q2019","4Q2019","1Q2020")

lastDayOfQuarter <- function(x){
     require(lubridate)
     result <- NULL
     months <-c(3,6,9,12)
     days <- c(31,30,30,31)

     for(i in 1:length(x)) {
          qtr <- as.numeric(substr(x[i],1,1))
          result[i] <- mdy(paste(months[qtr],days[qtr],(substr(x[i],3,6)),sep="-")) 
     }
     as.Date(result)

}
lastDayOfQuarter(dateStrings)

和输出：

>lastDayOfQuarter(dateStrings)
[1] "2019-03-31" "2019-06-30" "2019-09-30" "2019-12-31" "2020-03-31"
>