Question

我们有什么方法可以在if else循环中给出一个条件语句

 a= "06/28/2017 08:45"
 b= "06/28/2017 08:32"
 c= difftime(a,b,units="mins)
`if(a+30 > b)
 { 
  print("you are late")
  }else
  print("on time")`

我的数据框是

      col1                       col2
  6/27/2017 11:00 
  6/27/2017 20:45            
  6/24/2017 19:30               6/24/2017 18:48
  6/27/2017 20:00               6/28/2017 3:16
  6/29/2017 18:30               
  7/4/2017 7:30
  6/24/2017 1:30               6/24/2017 0:21
  6/29/2017 10:00
  6/28/2017 16:30              6/28/2017 18:39
  7/2/2017 19:00

我收到错误

 `1.Error in if (a+30 > b) missing value where TRUE/FALSE needed
  In Ops.factor(a+30 > b) :‘>’ not meaningful for factors
  2: In if (a+30 > b) { : the condition has length > 1 and only the first element will be used`

我要做的是向'a'添加30分钟并与'b'进行比较以确定某些事情是迟到还是准时。

Answer 1

如果您正确格式化日期并在if语句中使用减号而不是加号，那么它可以正常工作：

a= as.Date("06/28/2017 08:45", "%m/%d/%Y %H:%M")
b= as.Date("06/28/2017 08:32", "%m/%d/%Y %H:%M")

if(a-10 > b) { 
        print("you are late")
} else {
    print("on time")
}

将a-10改为-30，你会迟到的。

Answer 2

怎么样：

library(lubridate)
library(dplyr)
a= mdy_hm("06/28/2017 08:20")
b= mdy_hm("06/28/2017 08:32")
if_else(a + minutes(30) > b, "you are late", "on time")

Answer 3

library(lubridate)
a=mdy_hm("06/28/2017 08:45")
b=mdy_hm("06/28/2017 08:32")
c= abs(difftime(a,b,units="mins))
d=ifelse(30>c,"you are late","on time")
print(d)

给予时间条件

3 个答案: