[gradsusr] Area average only for California

[Yaqiang Wang]

It's quite easy to make a maskout grid data for GrADS using MeteoInfo
from a polygon shape file with 'Output Map Data' tool. Sample figures
are attached. Hope it will be helpful.

On Tue, May 22, 2012 at 12:46 PM, Jeff Duda <jeffduda319 at gmail.com> wrote:
> I agree with Yaqiang's suggestion.  The trick with this is that you need to
> have some additional information as to which lat/lon or which grid points in
> your domain are considered to be within the California borders.  Grads does
> not have the intrinsic ability to do that.  You'll have to supply your own
> data.  I'm sure it wouldn't be hard to find some data for this.  Good luck.
>
> Jeff
>
> On Mon, May 21, 2012 at 7:45 PM, Yaqiang Wang <yaqiang.wang at gmail.com>
> wrote:
>>
>> You need to produce a maskout data first in which the values of grid
>> points inside California are positive and the others are negtive. Then
>> use 'aave' function to get area average.
>>
>> On Tue, May 22, 2012 at 3:52 AM, rjmera <rjmera at coas.oregonstate.edu>
>> wrote:
>> > Hi, all. I've looked at some of the previous posts on this subject but I
>> > wasn't sure if it covered what I wanted to do. What I'm trying to do is
>> > to get area average for an irregular polygon. To be specific, the state
>> > of California, for example. This would exclude other states in the
>> > vicinity and the ocean. How should I proceed?
>> >
>> > Robert
>> >
>> > I'm using this version of grads:
>> >
>> > Grid Analysis and Display System (GrADS) Version 2.0.a9.oga.1
>> > Copyright (c) 1988-2010 by Brian Doty and the
>> > Institute for Global Environment and Society (IGES)
>> > GrADS comes with ABSOLUTELY NO WARRANTY
>> > See file COPYRIGHT for more information
>> >
>> > Config: v2.0.a9.oga.1 little-endian readline printim grib2 netcdf
>> > hdf4-sds hdf5 opendap-grids,stn athena geotiff shapefile
>> > Issue 'q config' command for more detailed configuration information
>> > Loading User Defined Extensions table
>> >
>> > </home/server/pi/homes/rjmera/grads/Contents/Linux/Versions/2.0.a9.oga.1/x86_64/gex/udxt>
>> > ... ok.
>> >
>> > _______________________________________________
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>> > gradsusr at gradsusr.org
>> > http://gradsusr.org/mailman/listinfo/gradsusr
>>
>>
>>
>> --
>> *************************************************
>> Dr. Yaqiang Wang
>> Chinese Academy of Meteorological Sciences (CAMS)
>> 46, Zhong-Guan-Cun South Avenue
>> Beijing, 100081
>> China
>>
>> yaqiang.wang at gmail.com
>>
>> http://www.meteothinker.com
>> **************************************************
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>
>
>
>
> --
> Jeff Duda
> Graduate research assistant
> University of Oklahoma School of Meteorology
> Center for Analysis and Prediction of Storms
>
>
> _______________________________________________
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> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>



-- 
*************************************************
Dr. Yaqiang Wang
Chinese Academy of Meteorological Sciences (CAMS)
46, Zhong-Guan-Cun South Avenue
Beijing, 100081
China

yaqiang.wang at gmail.com

http://www.meteothinker.com
**************************************************
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