[GRASSLIST:6999] Re: calculating center of intensity

[Jason Horn]

John,

Thanks for the response.  By center, I did not mean the geometric  
centroid, rather the center of intensity based on pixel values.  For  
reference, if you've ever used IDRISI, something like their CENTER  
module:

"center
Compute mean center (weighted or not) of a point distribution and  
standard radius (the two dimensional equivalent of a standard  
deviation)."

I have worked with folks in the Geography department, and I know that  
this sort of thing is relatively easy mathematically, I just wanted  
to know if it was possible with GRASS 6.0 as it is.

- Jason


On Jun 2, 2005, at 3:51 PM, Jonathan Greenberg wrote:

> Jason:
>
>     What do you mean by center?  Are you referring to a geometric  
> centroid, or the brightest pixel value falling within a poly, or  
> something else?  Have you chatted with any of the RS people at BU?   
> BU has one of the best remote sensing programs in the country (its  
> also my alma mater).
>
> --j
>
>
> On 6/2/05 12:42 PM, "Jason Horn" <jhorn at bu.edu> wrote:
>
>> Does anyone know of a way to calculate the center of a shape in a  
>> raster file based on shape and pixel values?  For example, imagine  
>> a NEXRAD RADAR image showing a storm cloud.  Could GRASS be used  
>> to calculate the center of the cloud?  I'm not having any luck  
>> finding a grass raster function to do this.
>>
>> Thanks,
>>
>> - Jason
>>
>>
>>
>>
>> Jason Horn
>>
>>
>> Boston University Department of Biology
>>
>>
>> 5 Cumington Street  Boston, MA 02215
>>
>>
>>
>>
>>
>> jhorn at bu.edu
>>
>>
>> office: 617 353 6987
>>
>>
>> cell: 401 588 2766
>>
>>
>>
>>
>
>
>
> -- 
> Jonathan A. Greenberg, PhD
> NRC Research Associate
> NASA Ames Research Center
> MS 242-4
> Moffett Field, CA 94035-1000
> 650-604-5896
> AIM: jgrn307
> MSN: jgrn307 at hotmail.com

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