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

[Charles Seman]

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
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