Re: Values inside a polygon

From: Adam Phillips <asphilli_at_nyahnyahspammersnyahnyah>
Date: Fri Jul 13 2012 - 16:12:54 MDT

Hi Nisha,
You can use the output from gc_inout:
http://www.ncl.ucar.edu/Document/Functions/Built-in/gc_inout.shtml
(See example #3)
gc_inout will return data of type logical, and you can use that data in
a where statement to mask out your data array.
http://www.ncl.ucar.edu/Document/Functions/Built-in/where.shtml
Then you can average over the remaining (non-missing) data.

Hope that helps.. If not, please respond to ncl-talk..
Adam

On 07/13/2012 02:35 PM, Manisha Ganeshan wrote:
> Hello,
>
> Is there a NCL function that can compute the indices of all points
> lying inside a pre-defined polygon? For example, I have used
> gsn_add_polygon function to draw a polygon on a contour map, but I now
> wish to find an average value of a quantity over points lying inside
> this polygon.
>
> Thanks,
> Nisha
>
>
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-- 
______________________________________________________________
Adam Phillips                                asphilli@ucar.edu
NCAR/Climate and Global Dynamics Division       (303) 497-1726
P.O. Box 3000				
Boulder, CO 80307-3000    http://www.cgd.ucar.edu/cas/asphilli

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Received on Fri Jul 13 16:13:03 2012

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