Reputation: 13
I am having troubles understanding why the code below behaves how it behaves. Basically, the filter seems to be applied but then fails to work in subsequent calls.
> library(dplyr)
> library(lubridate)
>
> md1 <- data.frame(no = 1:4, time = c("12:30:00", "13:30:00", "14:30:00", "15:30:00"))
> md1$time <- hms(md1$time)
> md1
no time
1 1 12H 30M 0S
2 2 13H 30M 0S
3 3 14H 30M 0S
4 4 15H 30M 0S
> md2 <- filter(md1, hour(time)<14)
> md2
no time
1 1 12H 30M 0S
2 2 13H 30M 0S
> hour(md2$time)
[1] 12 13 14 15
while I would like / expect to receive [1] 12 13 in the last call
Any suggestions welcome. It behaves the same in 3.3.1 and 3.4.0 versions of R (Windows 7)
Upvotes: 1
Views: 731
Reputation: 1540
md2 <- md1 %>%
+ mutate(time = format(time, format="%H:%M:%S")) %>%
+ filter(time < "14:00:00")
md2
no time
1 1 12H 30M 0S
2 2 13H 30M 0S
md2$time
[1] "12H 30M 0S" "13H 30M 0S"
If you want only the hour
hour(hms(as.character(md2$time)))
[1] 12 13
Upvotes: 1