The proportion of sampling completed by a fit writing to progress_dir, as a
number from 0 to 1.
Details
Pass the same directory given as progress_dir to a kb_fit_* function. This
reads fit progress from another R process: for example, a Shiny app can run
the fit in a background task and poll kb_fit_progress() from the main
session to drive a progress indicator. It returns 0 before sampling has
produced any output (or when the directory holds no fit artifact yet) and 1
once every chain has finished.
Examples
progress_dir <- tempfile()
dir.create(progress_dir)
# Before a fit has written anything, progress is 0.
kb_fit_progress(progress_dir)
#> [1] 0