set_loop_timechecker: Print elapsed and remaining time in iterative processes.

Description

set_loop_timechecker returns a function that records and prints processing time in iterative processes.

Usage

set_loop_timechecker(
  n_iter,
  overwrite = TRUE,
  timestep = 0.5,
  show_timestamp = TRUE,
  verbose = TRUE
)

Value

A function loop_timechecker. When placed at the end of the iterations, it records and prints the progress of iteration, elapsed time, and predicted remaining time. You can add arbitrary strings to the printed messages by using char_pre and char_post arguments.

Arguments

n_iter: The number of iterations.
overwrite: Logical. Should the message be overwritten?
timestep: The smallest time step of the output (sec).
show_timestamp: Logical. Should the time stamp be added to the message?
verbose: Logical. Should the progress be printed in the console?

Details

Provided with the number of iterations, this function creates a function named loop_timechecker which records and prints processing time in iterative process. In actual usage, it is recommended to call this function and creating loop_timechecker right before the iteration process, and place the loop_timechecker at the end of the iteration process.

If you want to keep all printed records in your console, please set overwrite = FALSE.

The timestep argument determines the frequency of updating printed information since too fast updates will decrease visibility.

Examples

Run this code

# \donttest{
iters <- 1:1000
ans <- NULL
tc <- set_loop_timechecker(length(iters))
for (i in iters) {
  ans <- c(ans, i)
  Sys.sleep(0.002)
  tc()
}

# For multiple loops, overwrite and char_pre arguments can be used for readability
iters1 <- 1:3
iters2 <- 1:100
ans <- NULL
tc1 <- set_loop_timechecker(length(iters1), overwrite = FALSE)
for (i in iters1) {
  tc2 <- set_loop_timechecker(length(iters2))
  for (j in iters2) {
    ans <- c(ans, i * j)
    Sys.sleep(0.004)
    tc2(char_pre = '-- ')
  }
  tc1()
}

# char_pre or char_post can also be used to check name of current process
iters <- paste0('case', LETTERS[1:10])
tc <- set_loop_timechecker(length(iters))
for (i in iters) {
  Sys.sleep(1)
  tc(char_post = paste0('  Processing ', i))
}
# }