如何在两个日期之间填充日期

如何解决如何在两个日期之间填充日期

这是我当前的数据框的样子：

df <- data.frame(name = c("A","A","B","B")),start_date = c("2020-01-23","2019-10-15","2019-07-28","2020-03-15","2019-04-23")),end_date = c("2020-05-15","2020-01-27","2019-10-17","2020-07-25","2020-02-13")),value = c(8.1,3.3,9.1,9.4,15.3)))



 name start_date   end_date value
    A 2020-01-23 2020-05-15     8
    A 2019-10-15 2020-01-27     3
    A 2019-07-28 2019-10-17     9
    B 2020-03-15 2020-07-25     9
    B 2019-04-23 2020-02-13    15

日期在 POSIXct 中，不一定是连续的，并且可以重叠。

我希望我的输出数据框看起来像这样：

name date  value
A 2020-01-23 8.1
A 2020-01-24 8.1
A ...        8.1
A 2020-05-14 8.1
A 2020-05-15 8.1
A 2019-10-15 3.3
A 2019-10-16 3.3
A ...        3.3
A 2020-01-26 3.3
A 2020-01-27 3.3
A 2019-07-28 9.1
A 2019-07-29 9.1
A ...        9.1
A 2019-10-16 9.1
A 2019-10-17 9.1
B 2020-03-15 9.4
B 2020-03-16 9.4
B ...        9.4
B 2020-07-24 9.4
B 2020-07-25 9.4
B 2019-04-23 15.3
B 2019-04-24 15.3
B ...        15.3
B 2020-02-12 15.3
B 2020-02-13 15.3

这是我一直在尝试的：

 library(data.table)
 setDT(df) [,.(date = seq(as.Date(start_date),as.Date(end_date),by = "day")),by = end_date]

但我一直收到以下错误：

Error in seq.Date(as.Date(start_date),by = "day") : 
  'from' must be of length 1

我该怎么做？如果它们工作得更好，我愿意使用其他包而不是 data.table。

解决方法

这里，我们可能需要使用 by 作为行序列

library(data.table)
setDT(df)[,.(date = seq(as.Date(start_date),as.Date(end_date),by = 'day')),.(rn = seq_len(nrow(df)),name,value)][,rn := NULL][]

---

或者通过循环'start_date'、'end_date'的相应元素来创建一个list列，以在Map中创建一个日期序列，然后在unnest中创建list

library(tidyr)
library(magrittr)
setDT(df)[,.(name,date = Map(seq,MoreArgs = list(by = '1 day'),as.Date(start_date),as.Date(end_date)),value)] %>% 
   unnest(date)
# A tibble: 731 x 3
#   name  date       value
#   <chr> <date>     <dbl>
# 1 A     2020-01-23   8.1
# 2 A     2020-01-24   8.1
# 3 A     2020-01-25   8.1
# 4 A     2020-01-26   8.1
# 5 A     2020-01-27   8.1
# 6 A     2020-01-28   8.1
# 7 A     2020-01-29   8.1
# 8 A     2020-01-30   8.1
# 9 A     2020-01-31   8.1
#10 A     2020-02-01   8.1
# … with 721 more rows

,

另一种使用 purrr

的方法

df <- data.frame(name = c("A","A","B","B"),start_date = c("2020-01-23","2019-10-15","2019-07-28","2020-03-15","2019-04-23"),end_date = c("2020-05-15","2020-01-27","2019-10-17","2020-07-25","2020-02-13"),value = c(8.1,3.3,9.1,9.4,15.3))

library(dplyr)
library(purrr)

# function take in the name,start,end,value and generate a df fill as wanted
generate_fill <- function(name,value) {
  tibble(name = name,date = seq(as.Date(start),as.Date(end),by = "1 day"),value = value)
}

# Map the function to original df and combine the result 
bind_rows(
  pmap(list(df[["name"]],df[["start_date"]],df[["end_date"]],df[["value"]]),generate_fill))

输出

# A tibble: 731 x 3
   name  date       value
   <chr> <date>     <dbl>
 1 A     2020-01-23   8.1
 2 A     2020-01-24   8.1
 3 A     2020-01-25   8.1
 4 A     2020-01-26   8.1
 5 A     2020-01-27   8.1
 6 A     2020-01-28   8.1
 7 A     2020-01-29   8.1
 8 A     2020-01-30   8.1
 9 A     2020-01-31   8.1
10 A     2020-02-01   8.1
# … with 721 more rows