[R] printing a variable during a loop

Joshua Wiley jwiley.psych at gmail.com
Fri Oct 22 17:46:31 CEST 2010


I'm glad this has helped both of you, but as a note, David deserves
the credit here---I just put the code together and tested it on
Windows.

Josh

On Fri, Oct 22, 2010 at 3:59 AM,  <J.delasHeras at ed.ac.uk> wrote:
>
> 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
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> Edinburgh EH9 3JR
> UK
>
>
> --
> The University of Edinburgh is a charitable body, registered in
> Scotland, with registration number SC005336.



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