How do I convert milliseconds to minutes and seconds?

I want to convert milliseconds values in my data to minutes and seconds (in the format MM:SS e.g. a value of 1772094 should become 29:32).

The toy data looks like this:

df <- data.frame(
  ID = c("ID1", "ID2", "ID3"),
  duration = c(1723456, 1834537, 1945678)
)

The output I want is:

id	duration
ID1	28:43
ID2	30:35
ID3	32:26

I have gotten close but not perfect with the below code.

library(dplyr)
library(lubridate)
library(hms)

df2 <- df %>%
  mutate(duration_ms = seconds_to_period(duration/1000)) %>% 
  mutate(duration_ms = hms::hms(duration_ms))

I divide my millisecond values by a thousand to turn them into seconds so they can be used by the seconds_to_period() function in lubridate and then format them with hms.

But it's currently HH:MM:SS with the seconds having decimal places (not rounded).

How do I turn millisecond values into minutes and seconds values in the format MM:SS in R?

Solution

You can simply round() when you divide duration by 1000:

df %>%
    mutate(duration_ms = seconds_to_period(round(duration / 1000))) %>%
    mutate(duration_ms = hms::hms(duration_ms))

#    ID duration duration_ms
# 1 ID1  1723456    00:28:43
# 2 ID2  1834537    00:30:35
# 3 ID3  1945678    00:32:26

Note that rounding means that your second example, which is in fact 00:30:34.537 seconds, becomes 00:30:35. If you prefer to always round down you can use floor():

df %>%
    mutate(duration_ms = seconds_to_period(floor(duration / 1000))) %>%
    mutate(duration_ms = hms::hms(duration_ms))

#    ID duration duration_ms
# 1 ID1  1723456    00:28:43
# 2 ID2  1834537    00:30:34
# 3 ID3  1945678    00:32:25