[R] commenting out a block of R code

[(Ted Harding)]

In vim, first move to the top line of the block.
Then press Shift+V (i.e. upper-case V); this line will then be
highlighted.
Then move down (down-arrow key) to the bottom line of the block;
the whole block will then be highlighted.

At this stage enter

:s/^/# /

(The "g" in Don's sequence is not needed -- it is for global
substitution within a line).

This is easy and quick in vim, and does not require entering line
numbers. I'm not sure now (long time since I used vi) whether
it also works as stated for vi.

Ted.

On 07-May-2012 03:16:36 Don McKenzie wrote:
> in vi (vim too?), in edit mode
> 
>:a,bs/^/# /g
> 
> inserts "# " at the beginning of lines a through b
> 
> 
> On 6-May-12, at 7:41 PM, Joshua Wiley wrote:
> 
>> Hi Ranjan,
>>
>> To me, this is really a text editors job.  Feature-rich editors make
>> it trivial, for example in Emacs, you can select a region (whatever
>> size you want) and M-x comment-region automatically comments every
>> line in that region.  Similarly M-x uncomment-region will uncomment
>> every line.  If you were doing this all the time, you could bind some
>> keyseries to do it for you.  Vim has something similar, though I
>> forget the exact command.
>>
>> A hack is:
>>
>> if (FALSE) {
>> all the lines
>> you want
>> to be `commented'
>> }
>>
>> which will leave them unevaluated at least.  Both of these have been
>> suggested before on the list, which is probably why Brian Ripley
>> suggested searching the archives.
>>
>> Cheers,
>>
>> Josh
>>
>>
>> On Sun, May 6, 2012 at 7:31 PM, Ranjan Maitra <maitra at iastate.edu>  
>> wrote:
>>> Dear friends,
>>>
>>> Is there an easy way of commenting out a block of R code after it has
>>> been written? (I am aware that R-aware editors can insert #
>>> line-by-line while it is being written, but I want to basically block
>>> out chunks of R code in a few strokes.)
>>>
>>> This question was asked on this mailing list some time ago: Professor
>>> Ripley's answer was to try the following:
>>>
>>> RSiteSearch(string="comment multiple lines")
>>>
>>> Perfectly fine, but inexplicably, I got searches back (seven
>>> pages) which do not seem to have any connection with what I am  
>>> looking
>>> for.
>>>
>>> Is there an easy way of doing this?
>>>
>>> Many thanks and best wishes,
>>> Ranjan
>>>
>>> ______________________________________________
>>> 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
>> Programmer Analyst II, Statistical Consulting Group
>> University of California, Los Angeles
>> https://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.
> 
> In science, 'fact' can only mean 'confirmed to such a degree that it  
> would be perverse
> to withhold provisional assent.' I suppose that apples might start to  
> rise tomorrow,
> but the possibility does not merit equal time in physics classrooms.
>     -- Stephen Jay Gould
> 
> 
> 
> Don McKenzie, Research Ecologist
> Pacific Wildland Fire Sciences Lab
> US Forest Service
> phone: 206-732-7824
> 
> Affiliate Professor
> School of Environmental and Forest Sciences
> University of Washington
> 
> ______________________________________________
> 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.

-------------------------------------------------
E-Mail: (Ted Harding) <Ted.Harding at wlandres.net>
Date: 07-May-2012  Time: 08:27:10
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