I am very new to R programming and kind of stuck in this:
I have a dataframe and I want check if there any value in any of the rows/columns which is in date format, should be stripped off to only time part.
For example a date string of "2015-01-02 10:15:44" should be changed to "10:15:44"
I know, it's very novice approach, but here is what I am trying to take substring of all values.
id<-c(1,2,3,4)
time1<-c("2015-01-02 10:15:44","NA","2015-11-12 00:15:44","2015-01-02 12:15:14")
time2<-c("NA", "2015-01-02 10:15:44","NA","2015-11-12 00:15:44")
..
..
timen ....
print(df)
df<-data.frame(id,time1, time2,..., timen)
df[1:4 ,2: ncol(df)] <- substring(df[1:4 ,2: ncol(df)], 12)
print(df)
Can someone please suggest a way out?
Loop through columns and substring:
df[, 2:3] <- lapply(df[, 2:3], substring, first = 12)
df
# id time1 time2
# 1 1 10:15:44
# 2 2 10:15:44
# 3 3 00:15:44
# 4 4 12:15:14 00:15:44
# input data
df <- data.frame(id = c(1,2,3,4),
time1 = c("2015-01-02 10:15:44","NA","2015-11-12 00:15:44","2015-01-02 12:15:14"),
time2 = c("NA", "2015-01-02 10:15:44","NA","2015-11-12 00:15:44"))