[R] Console display "buffer size"

[Robert Baer]

On 4/1/2013 4:08 PM, Peter Ehlers wrote:
> On 2013-04-01 13:37, Ted Harding wrote:
>> Greetings All.
>> This is a somewhat generic query (I'm really asking on behalf
>> of a friend who uses R on Windows, whereas I'm on Linux, but
>> the same phenomenon appears on both).
>>
>> Say one has a largish dataframe -- call it "G" -- which in the
>> case under discussion has 592 rows and 41 columns. The intention
>> is to display the data by simply entering its name (G) as command.
>>
>> Say the display console has been set wide enough to display 15
>> columns (determined by lengths of column names). Then R will output
>> succesively to the console, in continuous flow:
>>    Chunk 1: rows 1:592 of columns 1:15
>>    Chunk 2: rows 1:592 of columns 16:30
>>    Chunk 3: rows 1:592 of columns 31:41
>> If the number of rows that can be displayed on the screen is, say, 60,
>> then only rows 533:592 of Chunk 3 will be visible in the first instance.
>>
>> However, on my Linux system at any rate, I can use Shift+PgUp to
>> scroll back up through what has been output to the console. It seems
>> that my friend proceeds similarly.
>>
>> But now, after a certain number of (Shift+PgUps), one runs out
>> of road before getting to Row 1 of Chunk 1 (in my friend's case,
>> only Rows 468-592 of Chunk 1 can be seen).
>>
>> The explanation which occurs to me is that the console has a "buffer"
>> in which such an output is stored, and if the dataframe is too big
>> then lines 1:N (for some N) of the output are dropped from the start
>> of the buffer, and it is impossible to go further back than line (N+1)
>> of Chunk 1 where in this case N=467 (of course one may not even be
>> able to go further back than Chunk K, for some K > 1, for a bigger
>> dataframe).
>>
>> The query I have is: In the light of the above, is there a way to
>> change the size of the "buffer" so that one can scroll all the way
>> back to the very first row of Chunk 1? (The size-change may perhaps
>> have to be determined empirically).
>
> Isn't this set by the 'bufbytes' and 'buflines' specifications in the
> Rconsole file?
> Anyway, it's probably best to use 'View' to inspect data.
>
Although I have not tried them, Windows RGUI  [ -- Edit | GUI 
Preferences --] has settings for both buffer and lines which on my 
64-bit machine default to 250000 and 8000 respectively.

Rob Baer

> Peter Ehlers
>
>>
>> With thanks,
>> Ted.
>>
>> -------------------------------------------------
>> E-Mail: (Ted Harding) <Ted.Harding at wlandres.net>
>> Date: 01-Apr-2013  Time: 21:37:17
>> This message was sent by XFMail
>>
>> ______________________________________________
>> 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.
>>
>
> ______________________________________________
> 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.


-- 

Robert W. Baer, Ph.D.
Professor of Physiology
Kirksille College of Osteopathic Medicine
A. T. Still University of Health Sciences
Kirksville, MO 63501 USA