[R-sig-Geo] How to deal with data points having the same lat long position?

[Clint Bowman]

Jose,

Are your units of yield in quantity/area or total quantity?  If yield is 
quantity/area, I think I would compute the average for each county with a 
reported yield.

Clint

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On Fri, 5 Sep 2014, Christopher Swingley wrote:

> Jose,
>
> On Fri, Sep 5, 2014 at 10:29 AM, José Luis Rotundo <jrotundo at unr.edu.ar> wrote:
>> I am working with a database of farm yields across USA and the objective is
>> to map soybean yields. To preserve the identity of the farmers, they only
>> provided the zipcode of the farm. Then I attached the zip code lat and
>> long. The problem I have is that several farms belongs to the same zipcode
>> and therefore they have the same lat and long. Having this repeated
>> locations troubles the construction of the variogram.
>
> Wouldn't it be better to attach the sum of the soybean yields assigned
> to a zip code to a vector layer containing zip code boundaries?  I can
> imagine that if you assign values to a single point (even jittered
> when there are duplicates for single zip code) per zip code, that you
> won't wind up with a very accurate representation of the spatial
> pattern because the area each zip code covers will be different.
>
> Cheers,
>
> Chris
> -- 
> Christopher Swingley
> Fairbanks, Alaska
> http://swingleydev.com/
> cswingle at swingleydev.com
>
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