The duration filed on the Method class is incorrectly reported in summary

[mihaiconstantin]

The duration field of the Method class is determined based on

powerly/R/Method.R

Lines 172 to 179 in d6be4e6

	# Start the clock.
	private$.start_time <- Sys.time()
	# Run the method.
	private$.run(replications, monotone, increasing, df, solver_type, boots, lower_ci, upper_ci)
	# Stop the clock.
	private$.end_time <- Sys.time()

as

powerly/R/Method.R

Lines 184 to 185 in d6be4e6

	# Time elapsed until converged.
	duration = function() { return(private$.end_time - private$.start_time) },

and then reported in the summary as follows:

powerly/R/Method.R

Lines 210 to 211 in d6be4e6

	summary.Method <- function(object, ...) {
	cat("\n", "Method run completed (", as.numeric(round(object$duration, 4)), " sec):", sep = "")

When the method takes more the 60 seconds, the units of the duration field change from seconds to minutes, courtesy of the default difftime function. For example:

start <- Sys.time() - 61
end <- Sys.time()

print(start)
# "2022-04-29 15:22:52 CEST"

print(end)
# "2022-04-29 15:23:53 CEST"

duration <- end - start
cat("Method run completed (", as.numeric(round(duration, 4)), " sec)", sep = "")
# Method run completed (1.0194 sec)

I think it's better to just use the same unit everywhere, e.g.:

duration <- difftime(end, start, units = "secs")
cat("Method run completed (", as.numeric(round(duration, 4)), " sec)", sep = "")
# Method run completed (61.1642 sec)

This applies to other classes that have duration fields as well.