[R] printing a variable during a loop

[William Dunlap]

If you are using the Windows GUI you can turn
'output buffering' on and off by either typing
Ctrl-W or by using the Misc>Output Buffering
menu item.  When output buffering is off you
may not need to add flush.console() to your code.

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com  

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of 
> J.delasHeras at ed.ac.uk
> Sent: Friday, October 22, 2010 4:00 AM
> To: Joshua Wiley
> Cc: R-help
> Subject: Re: [R] printing a variable during a loop
> 
> 
> Thank you for this!
> 
> I had also wanted in the past to do this, and ended up writing dummy  
> files with informative names to a folder I set to collect these  
> messages, so I'd check the folder to see the new files being  
> generated... It did the job, and at the same time I could see 
> how long  
> it took for my program to reach certain points (filer creation time)  
> but not the most elegant! I didn't know about flush.console()
> 
> However I used that approach to generate some diagnostic files, so  
> that if a complex process broke (sometimes it involved 
> several system  
> calls to external programs) I had good information about what the  
> program was doing and at what stage it failed. I created a vector to  
> store teh names of all teh files being generated and they could be  
> removed automatically afterwards.
> 
> Not what the OP wanted, but this strategy may be useful for 
> certain tasks.
> 
> Jose
> 
> 
> Quoting Joshua Wiley <jwiley.psych at gmail.com>:
> 
> > On Thu, Oct 21, 2010 at 12:03 PM, David Winsemius
> > <dwinsemius at comcast.net> wrote:
> >>
> >> On Oct 21, 2010, at 8:58 PM, Antonio Olinto wrote:
> >>
> >>> Thanks Adrienne, but I still in doubt. The behavior of 
> print and message
> >>> looks the same.
> >>>
> >>> Nothing is displayed on the screen after minutes of 
> routine processing .
> >>> All values of "i" are displayed only when I press the 
> stop button   
> >>> (I'm under
> >>> Windows) or when "i" reaches the maximum value.
> >>>
> >>
> >> In the past people have needed to use flush.console() to 
> get output to the
> >> screen. Unable to test since A) I'm not running your OS, and B) no
> >> reproducible example offered.
> >
> > I am running your OS (though it would also be nice if you 
> reported the
> > results of sessionInfo() ).  In any case, this worked for me on R
> > 2.12.0 (i386-pc-mingw32):
> >
> > for(i in 1:6) {Sys.sleep(3); print(i); flush.console()}
> >
> > For your problem, I imagine something like (though untested 
> because no data):
> >
> > for (i in 1:23194) {
> > 
> dat.stat[i,c(2:8)]<-quantile(dat.bat[BL==block[i],2],prob=c(0,
0.025,0.25,0.5,0.75,0.975,1))
> > print(i)
> > flush.console()
> > }
> >
> >>
> >>> Thanks again,
> >>>
> >>> Antônio Olitno
> >>>
> >>>
> >>> Citando Adrienne Wootten <amwootte at ncsu.edu>:
> >>>
> >>>> instead of print use this
> >>>>
> >>>> message(i)
> >>>>
> >>>> the message command is used for things like this and it 
> will print the
> >>>> value
> >>>> of i as you are looping through, but you can also do this:
> >>>>
> >>>> message("Counter value is: ",i)
> >>>>
> >>>> which returns for i = 20 for example
> >>>>
> >>>> "Counter value is 20"
> >>>>
> >>>> for more check out the message help section in the html
> >>>>
> >>>> ? message
> >>>>
> >>>>
> >>>> Adrienne Wootten
> >>>> NCSU
> >>>>
> >>>> On Thu, Oct 21, 2010 at 2:05 PM, Antonio Olinto
> >>>> <aolinto_r at bignet.com.br>wrote:
> >>>>
> >>>>> Hello,
> >>>>>
> >>>>> About looping, consider the example:
> >>>>>
> >>>>> for (i in 1:23194) {
> >>>>>
> >>>>>
> >>>>> 
> dat.stat[i,c(2:8)]<-quantile(dat.bat[BL==block[i],2],prob=c(0,
0.025,0.25,0.5,0.75,0.975,1))
> >>>>> print(i)
> >>>>> }
> >>>>>
> >>>>> I'd like to have the value of "i" printed for each loop 
> (step). As I
> >>>>> could
> >>>>> see the values of "i" are shown on screen only after 
> all the work is
> >>>>> done.
> >>>>>
> >>>>> Thanks in advance for any suggestion.
> >>>>>
> >>>>> Best regards,
> >>>>>
> >>>>> Antonio
> >>>
> >> --
> >>
> >> David Winsemius, MD
> >> West Hartford, CT
> >>
> >> ______________________________________________
> >> R-help at r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
> >>
> >
> >
> >
> > --
> > Joshua Wiley
> > Ph.D. Student, Health Psychology
> > University of California, Los Angeles
> > http://www.joshuawiley.com/
> >
> > ______________________________________________
> > R-help at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
> 
> 
> 
> -- 
> Dr. Jose I. de las Heras                      Email: 
> J.delasHeras at ed.ac.uk
> The Wellcome Trust Centre for Cell Biology    Phone: +44 
> (0)131 6507095
> Institute for Cell & Molecular Biology        Fax:   +44 
> (0)131 6507360
> Swann Building, Mayfield Road
> University of Edinburgh
> Edinburgh EH9 3JR
> UK
> 
> 
> -- 
> The University of Edinburgh is a charitable body, registered in
> Scotland, with registration number SC005336.
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>