[R] Quadrat counting with spatstat

[David Winsemius]

On May 31, 2012, at 2:26 PM, R. Michael Weylandt wrote:

> On Thu, May 31, 2012 at 11:23 AM, AMFTom <the.quiet.room at gmail.com>  
> wrote:
>> I have photographs of plots that look like so:
>>
>> http://r.789695.n4.nabble.com/file/n4631960/Untitled.jpg
>>
>> I need to divide it up so each circle has an equal area surrounding  
>> it. So
>> into 20 equal segments, each of which contains a circle.  
>> Quadratcount is not
>> sufficient because if I divide it up into 36 equal quadrats, some  
>> quadrats
>> do not contain one of the circles.
>
> I must admit I found this a little confusing -- are you trying to
> divide into twenty segments or 36? Also, what package does
> quadratcount come from?
>
> I'm guessing this might work better in an image processing/computer
> vision program than in R.
>

The solution[1] requires a higher level of intelligence than is  
typical in ordinary clustering mechanisms. Maybe some sort of  
"symbolic geometry" program exists somewhere? There are really two  
levels of symmetry that need to be processed to come up with an  
approach that satisfies both constraints (equi-area-partition and all- 
area-included) . Agree it's not a statistical problem  ... not was it  
offered in a manner that lent itself to testing an algorithmic solution.

-- 
David.

[1] Which is too large to fit into the margins of this posting.

> Best,
> Michael
>
>>
>> I'm not even sure how to do it mathematically, let alone using R.
>>
>> Can anyone help?
>>
>> --
>> View this message in context: http://r.789695.n4.nabble.com/Quadrat-counting-with-spatstat-tp4631960.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
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>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT