[Rd] Feature request: txtProgressBar with ability to write to arbitrary stream

[Duncan Murdoch]

On 15/03/2011 8:46 AM, Matt Shotwell wrote:
> Here's a temporary fix; reassign 'cat' in the environment of
> 'txtProgressBar':
>
> tpbEnv<- new.env()
> assign("cat", function(...) cat(file=stderr(),...), tpbEnv)
> environment(txtProgressBar)<- tpbEnv

I would suggest renaming the function as well.  What's done above 
creates a new function called txtProgressBar, it doesn't modify the 
original one, so depending on scoping issues it may appear to only work 
sometimes.  But if you did

stderrProgressBar <- txtProgressBar
environment(stderrProgressBar) <- tpbEnv

you'll get clear messages if it is out of scope when you try to use it.

Duncan Murdoch

> Best,
> Matt
>
>
> On 03/15/2011 05:37 AM, Andreas Borg wrote:
> >  Hi all,
> >
> >  I use txtProgressBar to monitor progress of large computations. What I
> >  miss is the ability to redirect the progress bar to a stream other than
> >  stdout, specifically to the message stream. This would be useful for
> >  running Sweave scripts: When redirected to stderr, the bar could be
> >  visible even though console output is diverted to the output file (and
> >  there would be no cluttering of the generated latex).
> >
> >  I'd suggest the following changes to txtProgressBar:
> >  - a new argument 'file' (compare to 'cat') which defaults to stderr()
> >  (there might be reasons to use stdout(), but I believe a progress bar is
> >  mostly intended as a diagnostic tool and not for console output, which
> >  is printed or saved in some cases).
> >  - the calls to 'cat' that update the progress bar get 'file = file' as
> >  additional argument so that output is redirected as desired.
> >
> >  In case anyone from the core team is willing to incorparate this idea, I
> >  attached the patch file for the necessary changes below.
> >
> >  Best regards,
> >
> >  Andreas
> >
> >  3c3
> >  <  width = NA, title, label, style = 1)
> >  ---
> >   >  width = NA, title, label, style = 1, file=stderr())
> >  23c23
> >  <  cat(paste(rep.int(char, nb-.nb), collapse=""))
> >  ---
> >   >  cat(paste(rep.int(char, nb-.nb), collapse=""), file = file)
> >  27c27
> >  <  "\r", paste(rep.int(char, nb), collapse=""), sep = "")
> >  ---
> >   >  "\r", paste(rep.int(char, nb), collapse=""), sep = "", file = file)
> >  38c38
> >  <  cat("\r", paste(rep.int(char, nb), collapse=""), sep = "")
> >  ---
> >   >  cat("\r", paste(rep.int(char, nb), collapse=""), sep = "", file = file)
> >  42c42
> >  <  "\r", paste(rep.int(char, nb), collapse=""), sep = "")
> >  ---
> >   >  "\r", paste(rep.int(char, nb), collapse=""), sep = "", file = file)
> >  54c54
> >  <  cat(paste(c("\r |", rep.int(" ", nw*width+6)), collapse=""))
> >  ---
> >   >  cat(paste(c("\r |", rep.int(" ", nw*width+6)), collapse=""), file =
> >  file)
> >  59c59
> >  <  ), collapse=""))
> >  ---
> >   >  ), collapse=""), file = file)
> >  68c68
> >  <  cat("\n")
> >  ---
> >   >  cat("\n", file = file)
> >
>
>