R 使用带有日期的“小于”运算符

有一个数据框，包括三个日期度量，即date1、date2、date3和标记为s1和s2的附加度量。我正试图根据这些日期和测量值s1和s2创建标记为x1和x2的新列。例如，如果date1小于或等于date2，则列x1的值应为3，否则应保持s1的值。类似地，如果date1小于或等于date3，则列x2的值应为3，否则应保持s2的值。下面是数据的一部分

df <-
structure(
list(
  id = c(1L, 2L, 3L, 4L,5L),
  date1 = c("1/4/2004", "3/8/2004", "NA", "13/10/2004","11/3/2003"),
  date2 = c("8/6/2002", "11/5/2004", "3/5/2004", 
"25/11/2004","21/1/2004"),
  s1=c(1,2,1,"NA","NA"),
  date3=c("23/6/2006", "24/12/2006", "18/2/2006", "NA","NA"),
  s2=c("NA","NA",2,"NA","NA")
 ),
.Names = c("id", "date1","date2","s1","date3","s2"),
 class = "data.frame",
 row.names = c(NA,-5L),
 col_types = c("numeric", "date","date","numeric","date","numeric")
 ) 

---

由此看来，x2列中的NA似乎不响应代码，因为2004年8月3日小于2006年12月24日，因此我预计x2列中的NA将由3代替。有谁能澄清为什么会发生这种情况以及如何解决。非常感谢您的帮助。

日期列是数据中的字符类型

class(df$date1)
#[1] "character"

我们首先需要将它们转换为Date对象，然后进行比较

cols <- paste0("date", 1:3)
df[cols] <- lapply(df[cols], as.Date, "%d/%m/%Y")
df$x1<-ifelse(df$date1 <= df$date2, 3, df$s1)
df$x2<-ifelse(df$date1 <= df$date3, 3, df$s2)

df
#  id      date1      date2 s1      date3 s2   x1 x2
#1  1 2004-04-01 2002-06-08  1 2006-06-23 NA    1  3
#2  2 2004-08-03 2004-05-11  2 2006-12-24 NA    2  3
#3  3       <NA> 2004-05-03  1 2006-02-18  2 <NA> NA
#4  4 2004-10-13 2004-11-25 NA       <NA> NA    3 NA
#5  5 2003-03-11 2004-01-21 NA       <NA> NA    3 NA

class(df$date1)
#[1] "character"

cols <- paste0("date", 1:3)
df[cols] <- lapply(df[cols], as.Date, "%d/%m/%Y")
df$x1<-ifelse(df$date1 <= df$date2, 3, df$s1)
df$x2<-ifelse(df$date1 <= df$date3, 3, df$s2)

df
#  id      date1      date2 s1      date3 s2   x1 x2
#1  1 2004-04-01 2002-06-08  1 2006-06-23 NA    1  3
#2  2 2004-08-03 2004-05-11  2 2006-12-24 NA    2  3
#3  3       <NA> 2004-05-03  1 2006-02-18  2 <NA> NA
#4  4 2004-10-13 2004-11-25 NA       <NA> NA    3 NA
#5  5 2003-03-11 2004-01-21 NA       <NA> NA    3 NA

library(dplyr)
df %>%
  mutate_at(vars(starts_with("date")), as.Date, "%d/%m/%Y") %>%
  mutate(x1 = replace(s1, date1 <= date2, 3), 
         x2 = replace(s2, date1 <= date3, 3))