Zonal Statistics Summarize Zones

Dec 28, 2011 at 4:06 PM

This is either a suggestion for 4.next or a request with help using 4.current.  I need the ability to calculate the mean value of a raster within each polygon of a shapefile.  In ESRI-land this is called "Summarize Zones" within "Zonal Statistics."  ESRI has one shortcoming which I see no need to duplicate:  If polygons are small relative to pixels, ESRI in all its wisdom leaves some polygons out of the mix, apparently deeming that all available pixels have given their information to other polygons and have none left for the little guys.  I can see that for purposes of conservation of mass in pixel values this might make sense, but for every application I've ever used I'd just as soon know that ittybitty polygon "A" sees a value of "X" in the overlying raster, even if some other polygon is also looking at the same pixel.

Thanks,

Bryce

Coordinator
Dec 28, 2011 at 6:28 PM

This can be done with the PointInPolygon method.

You can loop through all cells of the raster to determin in what shape it is in.
Afterwards you can do some calculation of the cell values in the shape.

At this moment this is not available as a tool in the toolbox, but it can be done using the script editor or a custom plug-in/tool.

--
Paul

Dec 29, 2011 at 3:32 AM
Thanks. When I get a minute to breathe I'll see if I can figure out
how to do scripts, and use the PointInPolygon method.

Bryce

On Wed, Dec 28, 2011 at 12:28 PM, pmeems <notifications@codeplex.com> wrote:
> From: pmeems
>
> This can be done with the PointInPolygon method.
>
> You can loop through all cells of the raster to determin in what shape it is
> in.
> Afterwards you can do some calculation of the cell values in the shape.
>
> At this moment is not available as a tool in the toolbox, but it can be
> done using the script editor or a custom plug-in/tool.
>
> --
> Paul
>
> Read the full discussion online.
>
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Feb 2, 2012 at 4:15 PM

Hi there,

I'm looking for a simple script that uses the PointInPolygon method to play with in MapWindow's script editor. Does anyone have a simple script that works?

Eventually, I need to develop the tool that bcontor suggested.

Thank you,

Eric