How to add progress bar inside dplyr chain in R

Question

I like dplyr\'s \"progress_estimated\" function but I can\'t figure out how to get a progress bar to work inside a dplyr chain. I\'ve put a reproducible example with code at the

Answer 1

I dont really like my solution but it works.

print_tick_function <- function(x, p) {
  p$tick()$print()
  data.frame(x)
}

SunriseSet <- function(dataframe, timezone){
  p <- progress_estimated(nrow(dataframe))
  dataframe %>% 
    rowwise() %>% 
    do(print_tick_function(.,p)) %>%
    mutate(
      datetime = as.POSIXct(substr(cdatetime, 1, 20), tz = timezone),
      sunrise = sunrise.set(latitude, longitude, datetime, timezone, num.days = 1)[1,1]
    )
}
test2 <- SunriseSet(test, "CST6CDT")

Answer 2

Rather than using rowwise(), perhaps try pairing the map* functions from purrr with progress_estimated(). This answer follows the approach from https://rud.is/b/2017/03/27/all-in-on-r%E2%81%B4-progress-bars-on-first-post/.

First, wrap your function in another function that updates the progress bar:

SunriseSet <- function(lat, long, date, timezone, num.days, .pb = NULL) {
  if (.pb$i < .pb$n) .pb$tick()$print()
  sunrise.set(lat, long, date, timezone, num.days)
}

Then, iterate through your inputs with pmap, or pmap_df (to bind the outputs into a dataframe):

library(purrr)
pb <- progress_estimated(nrow(test), 0)
test2 <- test %>% 
  mutate(
    sunrise = pmap_df(
      list(
        lat = latitude, 
        long = longitude,
        date = as.character(cdatetime)
      ),
      SunriseSet,
      timezone = "CST6CDT", num.days = 1, .pb = pb
    )$sunrise
  )