R。 如何用日期替換數字或從數據框中刪除帶數字的行？

Question

我有這樣的數據框：

[701] "38760"      "38788"      "38819"      "38849"      "38880"      "38910"      "38941"     
[708] "38972"      "39002"      "39033"      "39063"      "12/13/2006" "12/14/2006" "12/15/2006"
[715] "12/16/2006" "12/17/2006" "12/18/2006" "12/19/2006" "12/20/2006" "12/21/2006" "12/22/2006"
[722] "12/23/2006" "12/24/2006" "12/25/2006" "12/26/2006" "12/27/2006" "12/28/2006" "12/29/2006"
[729] "12/30/2006" "12/31/2006"

我只想有日期（替換或刪除數字）。 任何人都知道一些合理的快速方法來做到這一點？ 請幫忙。

Answer 1

假設我們在data.frame中有一個“日期”列，它只包含兩種格式 - 1) %m/%d/%Y和 2) 數值 - 然后我們應用as.Date格式%m/%d/%Y在整個“日期”上。 如果值是數字，它將返回NA ，我們單獨執行並在base R中更新

dates1 <- with(df1, as.Date(dates, format = "%m/%d/%Y"))
dates1[is.na(dates1)] <- with(df1, as.Date(as.integer(dates[is.na(dates1)]), 
       origin = "1899-12-30"))
df1$dates <- dates1

-輸出

> df1$dates
 [1] "2006-02-12" "2006-03-12" "2006-04-12" "2006-05-12" "2006-06-12" "2006-07-12" "2006-08-12" "2006-09-12" "2006-10-12" "2006-11-12" "2006-12-12" "2006-12-13"
[13] "2006-12-14" "2006-12-15" "2006-12-16" "2006-12-17" "2006-12-18" "2006-12-19" "2006-12-20" "2006-12-21" "2006-12-22" "2006-12-23" "2006-12-24" "2006-12-25"
[25] "2006-12-26" "2006-12-27" "2006-12-28" "2006-12-29" "2006-12-30" "2006-12-31"

數據

df1 <- structure(list(dates = c("38760", "38788", "38819", "38849", 
"38880", "38910", "38941", "38972", "39002", "39033", "39063", 
"12/13/2006", "12/14/2006", "12/15/2006", "12/16/2006", "12/17/2006", 
"12/18/2006", "12/19/2006", "12/20/2006", "12/21/2006", "12/22/2006", 
"12/23/2006", "12/24/2006", "12/25/2006", "12/26/2006", "12/27/2006", 
"12/28/2006", "12/29/2006", "12/30/2006", "12/31/2006")),
 class = "data.frame", row.names = c(NA, 
-30L))

Answer 2

我假設它是Excel日期。 所以現在你可以使用as.Date的origin參數，即 1899 年 12 月 30 日。

library(dplyr)
df %>% 
  mutate(date = as.Date(date, origin = "1899-12-30"))

       date Przedmiescie Centrum
1 2005-01-01            0       0
2 2005-02-01            0       0
3 2005-03-01            0       0
4 2005-04-01            0       0
5 2005-05-01            0       2
6 2005-06-01            0       0

數據：

structure(list(date = c(38353L, 38384L, 38412L, 38443L, 38473L, 
38504L), Przedmiescie = c(0L, 0L, 0L, 0L, 0L, 0L), Centrum = c(0L, 
0L, 0L, 0L, 2L, 0L)), class = "data.frame", row.names = c("1", 
"2", "3", "4", "5", "6"))

Answer 3

我有這樣的數據框：

date  Przedmieście Centrum
   <chr>        <dbl>   <dbl>
 1 38353            0       0
 2 38384            0       0
 3 38412            0       0
 4 38443            0       0
 5 38473            0       2
 6 38504            0       0

我有數字而不是日期，我需要有日期（從 2005 年到 2006 年）