Transform vector of seconds and a start time to a proper timestamp-CodePudding

Consider the following data

library(lubridate)

df <- data.frame(x_seconds = c(1,2,3,4,5))

start_time <- ymd_hms("2022-01-01 13:45:00")

How do I get the vector of seconds into a vector of timestamps since the start_time?

# A tibble: 5 x 2
  x_seconds z_ts
      <dbl> <dttm>
1         1 2022-01-01 13:45:01
2         2 2022-01-01 13:45:02
3         3 2022-01-01 13:45:03
4         4 2022-01-01 13:45:04
5         5 2022-01-01 13:45:05

Note that a solution should work for an (arbitrary) large vector of seconds.

CodePudding user response：

Simply

library(dplyr)

start_time <- ymd_hms("2022-01-01 13:45:00")
df %>%
  mutate(z_ts = x_seconds   start_time)

  x_seconds                z_ts
1         1 2022-01-01 13:45:01
2         2 2022-01-01 13:45:02
3         3 2022-01-01 13:45:03
4         4 2022-01-01 13:45:04
5         5 2022-01-01 13:45:05

or using base R

df$z_ts = df$x_seconds   start_time
df

  x_seconds                z_ts
1         1 2022-01-01 13:45:01
2         2 2022-01-01 13:45:02
3         3 2022-01-01 13:45:03
4         4 2022-01-01 13:45:04
5         5 2022-01-01 13:45:05