Calculate length of night in data frame-CodePudding

I have a some test data with two columns. The column "hour" shows hourly values (p.m.). The column "day" indicates the corresponding day, i.e. on day 1 there are hourly values from 7 to 11 o'clock.

I now want to calculate how big the time span is for each day and store these values in a vector.

Something like:

timespan <- c(5,7,3)

How could I calculate this in a loop? I thought about something like length(unique...)

Thanks in advance!

Here is the code:

day <- c(1,1,1,1,1,2,2,2,2,2,3,3,3,3,3)
hour <- c(7,7,8,10,11,5,6,6,7,11,9,10,10,11,11)

df <- data.frame(day,hour)

CodePudding user response：

library(dplyr)

df %>%
  group_by(day) %>%
  summarise(time_span = max(hour) - min(hour)   1)

## A tibble: 3 x 2
#     day time_span
#   <dbl>     <dbl>
# 1     1         5
# 2     2         7
# 3     3         3