Report on Progress while Evaluating an R Expression

with_progress(
  expr,
  handlers = progressr::handlers(),
  cleanup = TRUE,
  delay_terminal = NULL,
  delay_stdout = NULL,
  delay_conditions = NULL,
  interval = NULL,
  enable = NULL
)

without_progress(expr)

Arguments

expr

An R expression to evaluate.

handlers

A progression handler or a list of them. If NULL or an empty list, progress updates are ignored.

cleanup

If TRUE, all progression handlers will be shutdown at the end regardless of the progression is complete or not.

delay_terminal

If TRUE, output and conditions that may end up in the terminal will delayed.

delay_stdout

If TRUE, standard output is captured and relayed at the end just before any captured conditions are relayed.

delay_conditions

A character vector specifying base::condition classes to be captured and relayed at the end after any captured standard output is relayed.

interval

(numeric) The minimum time (in seconds) between successive progression updates from handlers.

enable

(logical) If FALSE, then progress is not reported. The default is to report progress in interactive mode but not batch mode. See below for more details.

Value

Returns the value of the expression.

Details

IMPORTANT: This function is meant for end users only. It should not be used by R packages, which only task is to signal progress updates, not to decide if, when, and how progress should be reported.

without_progress() evaluates an expression while ignoring all progress updates.

Progression handler functions

Formally, progression handlers are calling handlers that are called when a progression condition is signaled. These handlers are functions that takes one argument which is the progression condition.

Progress updates in batch mode

When running R from the command line, R runs in a non-interactive mode (interactive() returns FALSE). The default behavior of with_progress() is to not report on progress in non-interactive mode. To have progress being reported on also then, set R options progressr.enable or environment variable R_PROGRESSR_ENABLE to TRUE. Alternatively, one can set argument enable=TRUE when calling with_progress(). For example,

$ Rscript -e "library(progressr)" -e "with_progress(slow_sum(1:5))"

will not report on progress, whereas:

$ export R_PROGRESSR_ENABLE=TRUE
$ Rscript -e "library(progressr)" -e "with_progress(slow_sum(1:5))"

will.

See also

Examples

## The slow_sum() example function slow_sum <- progressr::slow_sum print(slow_sum)
#> function (x, delay = getOption("progressr.demo.delay", 1), stdout = FALSE, #> message = TRUE) #> { #> p <- progressor(along = x) #> sum <- 0 #> for (kk in seq_along(x)) { #> p(amount = 0) #> Sys.sleep(0.2 * delay) #> if (stdout) #> cat(sprintf("O: Element #%d\n", kk)) #> p(amount = 0) #> Sys.sleep(0.2 * delay) #> p(amount = 0) #> Sys.sleep(0.2 * delay) #> sum <- sum + x[kk] #> p(message = sprintf("P: Adding %g", kk)) #> Sys.sleep(0.2 * delay) #> if (message) #> message(sprintf("M: Added value %g", x[kk])) #> p(amount = 0) #> Sys.sleep(0.2 * delay) #> } #> p(amount = 0) #> sum #> } #> <bytecode: 0x5596775fe2a8> #> <environment: namespace:progressr>
x <- 1:10 ## Without progress updates y <- slow_sum(x)
#> M: Added value 1
#> M: Added value 2
#> M: Added value 3
#> M: Added value 4
#> M: Added value 5
#> M: Added value 6
#> M: Added value 7
#> M: Added value 8
#> M: Added value 9
#> M: Added value 10
## Progress reported via txtProgressBar (default) handlers("txtprogressbar") ## default with_progress({ y <- slow_sum(x) })
#> M: Added value 1
#> M: Added value 2
#> M: Added value 3
#> M: Added value 4
#> M: Added value 5
#> M: Added value 6
#> M: Added value 7
#> M: Added value 8
#> M: Added value 9
#> M: Added value 10
## Progress reported via tcltk::tkProgressBar if (capabilities("tcltk") && requireNamespace("tcltk", quietly = TRUE)) { handlers("tkprogressbar") with_progress({ y <- slow_sum(x) }) }
#> M: Added value 1
#> M: Added value 2
#> M: Added value 3
#> M: Added value 4
#> M: Added value 5
#> M: Added value 6
#> M: Added value 7
#> M: Added value 8
#> M: Added value 9
#> M: Added value 10
## Progress reported via progress::progress_bar) if (requireNamespace("progress", quietly = TRUE)) { handlers("progress") with_progress({ y <- slow_sum(x) }) }
#> M: Added value 1
#> M: Added value 2
#> M: Added value 3
#> M: Added value 4
#> M: Added value 5
#> M: Added value 6
#> M: Added value 7
#> M: Added value 8
#> M: Added value 9
#> M: Added value 10
## Progress reported via txtProgressBar and beepr::beep if (requireNamespace("beepr", quietly = TRUE)) { handlers("beepr", "txtprogressbar") with_progress({ y <- slow_sum(x) }) }
#> M: Added value 1
#> M: Added value 2
#> M: Added value 3
#> M: Added value 4
#> M: Added value 5
#> M: Added value 6
#> M: Added value 7
#> M: Added value 8
#> M: Added value 9
#> M: Added value 10
## Progress reported via customized utils::txtProgressBar and beepr::beep, ## if available. handlers(handler_txtprogressbar(style = 3L)) if (requireNamespace("beepr", quietly = TRUE)) { handlers("beepr", append = TRUE) } with_progress({ y <- slow_sum(1:30) })
#> M: Added value 1
#> M: Added value 2
#> M: Added value 3
#> M: Added value 4
#> M: Added value 5
#> M: Added value 6
#> M: Added value 7
#> M: Added value 8
#> M: Added value 9
#> M: Added value 10
#> M: Added value 11
#> M: Added value 12
#> M: Added value 13
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#> M: Added value 15
#> M: Added value 16
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#> M: Added value 21
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#> M: Added value 30