R help - Mar 2006 - cat(), Rgui, and support for carriage return \r...

Hi, and thanks in advance for your time.

Background - I am working on a package and wish to have a routine's
progress reported. The routine can take some time, and I would like to
inform the user about the routine's progress. I have scoured the
archives but to no avail, so would like to solicit input from this list.

I am successfully using

cat("\rBootstrap replication ", i, " of ", boot.num,)
flush.console() # To flush stdout on windows systems

which works as expected on *NIX systems and using Rterm under windows.
However, under Rgui the carriage return \r is ignored, and I certainly
don't want to use the newline escape sequence \n. Under Rgui it appears
as

Bootstrap replication 1 of 399Bootstrap replication 2 of 399Bootstrap...

but I want it to function properly if at all possible.

My question is simply whether there is a portable way to implement this
so that it works regardless of the R platform the user may be working
on?

Many thanks for any/all suggestions.

-- Jeff

-- 
Professor J. S. Racine         Phone:  (905) 525 9140 x 23825
Department of Economics        FAX:    (905) 521-8232
McMaster University            e-mail: racinej at mcmaster.ca
1280 Main St. W.,Hamilton,     URL:
http://www.economics.mcmaster.ca/racine/
Ontario, Canada. L8S 4M4

`The generation of random numbers is too important to be left to

Here is a snip of code I used in a program that was looping for a really
long time, maybe this can be helpful. You will need the svMisc package.

print(i) 
progress(i)
Sys.sleep(.05) 

-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Jeffrey Racine
Sent: Friday, March 17, 2006 9:45 AM
To: r-help at stat.math.ethz.ch
Subject: [R] cat(), Rgui, and support for carriage return \r...

Hi, and thanks in advance for your time.

Background - I am working on a package and wish to have a routine's
progress reported. The routine can take some time, and I would like to
inform the user about the routine's progress. I have scoured the
archives but to no avail, so would like to solicit input from this list.

I am successfully using

cat("\rBootstrap replication ", i, " of ", boot.num,)
flush.console() # To flush stdout on windows systems

which works as expected on *NIX systems and using Rterm under windows.
However, under Rgui the carriage return \r is ignored, and I certainly
don't want to use the newline escape sequence \n. Under Rgui it appears
as

Bootstrap replication 1 of 399Bootstrap replication 2 of 399Bootstrap...

but I want it to function properly if at all possible.

My question is simply whether there is a portable way to implement this
so that it works regardless of the R platform the user may be working
on?

Many thanks for any/all suggestions.

-- Jeff

-- 
Professor J. S. Racine         Phone:  (905) 525 9140 x 23825
Department of Economics        FAX:    (905) 521-8232
McMaster University            e-mail: racinej at mcmaster.ca
1280 Main St. W.,Hamilton,     URL:
http://www.economics.mcmaster.ca/racine/
Ontario, Canada. L8S 4M4

`The generation of random numbers is too important to be left to

______________________________________________
R-help at stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html

You could try this:

eol <- if (Platform$OS.type == "windows") "\n" else
"\r"

and then use the eol variable in your cat statement.

On 3/17/06, Jeffrey Racine <racinej at mcmaster.ca>
wrote:
> Hi, and thanks in advance for your time.
>
> Background - I am working on a package and wish to have a routine's
> progress reported. The routine can take some time, and I would like to
> inform the user about the routine's progress. I have scoured the
> archives but to no avail, so would like to solicit input from this list.
>
> I am successfully using
>
> cat("\rBootstrap replication ", i, " of ", boot.num,)
> flush.console() # To flush stdout on windows systems
>
> which works as expected on *NIX systems and using Rterm under windows.
> However, under Rgui the carriage return \r is ignored, and I certainly
> don't want to use the newline escape sequence \n. Under Rgui it appears
> as
>
> Bootstrap replication 1 of 399Bootstrap replication 2 of 399Bootstrap...
>
> but I want it to function properly if at all possible.
>
> My question is simply whether there is a portable way to implement this
> so that it works regardless of the R platform the user may be working
> on?
>
> Many thanks for any/all suggestions.
>
> -- Jeff
>
> --
> Professor J. S. Racine         Phone:  (905) 525 9140 x 23825
> Department of Economics        FAX:    (905) 521-8232
> McMaster University            e-mail: racinej at mcmaster.ca
> 1280 Main St. W.,Hamilton,     URL:
> http://www.economics.mcmaster.ca/racine/
> Ontario, Canada. L8S 4M4
>
> `The generation of random numbers is too important to be left to
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>

On 3/17/2006 9:44 AM, Jeffrey Racine wrote:
> Hi, and thanks in advance for your time.
> 
> Background - I am working on a package and wish to have a routine's
> progress reported. The routine can take some time, and I would like to
> inform the user about the routine's progress. I have scoured the
> archives but to no avail, so would like to solicit input from this list.
> 
> I am successfully using
> 
> cat("\rBootstrap replication ", i, " of ", boot.num,)
> flush.console() # To flush stdout on windows systems
> 
> which works as expected on *NIX systems and using Rterm under windows.
> However, under Rgui the carriage return \r is ignored, and I certainly
> don't want to use the newline escape sequence \n. Under Rgui it appears
> as
> 
> Bootstrap replication 1 of 399Bootstrap replication 2 of 399Bootstrap...
> 
> but I want it to function properly if at all possible.
> 
> My question is simply whether there is a portable way to implement this
> so that it works regardless of the R platform the user may be working
> on?
> 
> Many thanks for any/all suggestions.
This looks like it would be a useful addition to Rgui to support this. 
The problem is that on Unix or Rterm, it isn't actually R that does 
anything, it's the display that handles the CR with no LF.  Rgui uses a 
different mechanism for putting text on the screen, so this would have 
to be implemented specially.

Just out of interest:  does the Mac OS X gui handle this like the ascii 
terminals or like Windows Rgui?

Duncan Murdoch

On 3/17/2006 9:44 AM, Jeffrey Racine wrote:
> Hi, and thanks in advance for your time.
> 
> Background - I am working on a package and wish to have a routine's
> progress reported. The routine can take some time, and I would like to
> inform the user about the routine's progress. I have scoured the
> archives but to no avail, so would like to solicit input from this list.
> 
> I am successfully using
> 
> cat("\rBootstrap replication ", i, " of ", boot.num,)
> flush.console() # To flush stdout on windows systems
> 
> which works as expected on *NIX systems and using Rterm under windows.
> However, under Rgui the carriage return \r is ignored, and I certainly
> don't want to use the newline escape sequence \n. Under Rgui it appears
> as
> 
> Bootstrap replication 1 of 399Bootstrap replication 2 of 399Bootstrap...
> 
> but I want it to function properly if at all possible.
> 
> My question is simply whether there is a portable way to implement this
> so that it works regardless of the R platform the user may be working
> on?
> 
> Many thanks for any/all suggestions.
I've just been looking at the source code for this.  I think it will be 
relatively easy to make \r in Rgui do a destructive CR (i.e. it will 
return to the start of the line, but clear any existing characters). 
I'll play around a bit and then do that for R-devel.

In the meantime, \b does a destructive backspace, so you can get the 
effect you want with something like this:

msg <- ""
for (i in 1:1000) {
    cat(rep("\b", nchar(msg)), sep="")
    msg <- paste("Message ", i)
    cat(msg)
    flush.console()
}

This seems to work in Rgui, Rterm, (and R on Unix, if you get rid of the 
flush.console call).

Duncan Murdoch