find the location of the max value over a lat-long domain

[Jainn J. Shi (aka Roger)]

Chuck,

Thanks a lot. This is exactly what I was looking for.

Roger

Charles Seman wrote:
> Roger,
>
> Here's a copy of part of an email reply posted to the Listserv by
> Jennifer Adams (COLA) from Aug 2002 (which was saved to a local file for
> reference):
>
> ---
> Try this little bit of script code -- modify to suit your
> data. This example draws a mark where the maximum of a
> global variable called "air" is located in the xy plane.
>
> 'set warn off'
> 'd maxloc(max(air,lon=0,lon=360),lat=-90,lat=90)'
> ygrd = subwrd(result,4)
> 'd maxloc(max(air,lat=-90,lat=90),lon=0,lon=360)'
> xgrd = subwrd(result,4)
> 'set x 'xgrd
> lonval = subwrd(result,4)
> 'set y 'ygrd
> latval = subwrd(result,4)
> 'q w2xy 'lonval' 'latval
> xpos = subwrd(result,3)
> ypos = subwrd(result,6)
> 'draw mark 1 'xpos' 'ypos' .2'
> ---
>
> Hope it helps,
> Chuck
>
> Roger Shi wrote:
>> Hi,
>>
>> I am having problems to find the location of the max value over a
>> lat-long domain. GrADS only provides the "maxloc" function which only
>> loop through one dimension, e.g.
>>
>> maxloc(expr, dim1, dim2 <,tinc>)
>>
>> expr    - any valid GrADS expression
>> dim1    - the starting dimension expression
>> dim2    - the ending dimension expression
>> tinc    - optional time increment
>>
>> Is there any way to loop through both x and y dimensions at the same
>> time?
>>
>> Best regards,
>> Roger Shi
>
> --
>
> Please note that Charles.Seman at noaa.gov should be considered my NOAA
> email address, not cjs at gfdl.noaa.gov.
>
> ********************************************************************
> Charles Seman                                Charles.Seman at noaa.gov
> U.S. Department of Commerce / NOAA / OAR
> Geophysical Fluid Dynamics Laboratory         voice: (609) 452-6547
> 201 Forrestal Road                              fax: (609) 987-5063
> Princeton, NJ  08540-6649            http://www.gfdl.noaa.gov/~cjs/
> ********************************************************************
>
> "The contents of this message are mine personally and do not necessarily
> reflect any position of the Government or NOAA."


--
================================================
Dr. Jainn Jong Shi (aka Roger)
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Code 613.1
NASA/Goddard Space Flight Center
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email: shi at agnes.gsfc.nasa.gov
http://atmospheres.gsfc.nasa.gov/cloud_modeling