[gradsusr] hdivg function

[Yaqiang Wang]

Thanks for Jeff's reply! But it seems that in GrADS the hdivg function
was calculated as following. Please mention the last sentence.

define dv = cdiff(v,x)
define dx = cdiff(lon,x)*3.1416/180
define du = cdiff(u*cos(lat*3.1416/180),y)
define dy = cdiff(lat,y)*3.1416/180
display (du/dy+dv/dx)/(6.37e6*cos(lat*3.1416/180))

Yaqiang

Chinese Academy of Meteorological Sciences
yaqiang.wang at gmail.com

On Mon, Nov 15, 2010 at 11:56 AM, Jeffrey Duda <jdduda at iastate.edu> wrote:
> Yaqiang,
> You are exactly correct.
>
> Jeff Duda
>
> On Sun, Nov 14, 2010 at 9:22 PM, Yaqiang Wang <yaqiang.wang at gmail.com>
> wrote:
>>
>> The GrADS documentation said that the cdiff function may be used to
>> duplicate the calculation done by the hcurl function:
>>
>> define dv = cdiff(v,x)
>> define dx = cdiff(lon,x)*3.1416/180
>> define du = cdiff(u*cos(lat*3.1416/180),y)
>> define dy = cdiff(lat,y)*3.1416/180
>> display (dv/dx-du/dy)/(6.37e6*cos(lat*3.1416/180))
>>
>> But there is no description of hdivg function. I guess hdivg function
>> could be duplicated using cdiff function as following. Please anybody
>> tell me if it is correct or not. Thanks!
>>
>> define dv = cdiff(v,x)
>> define dx = cdiff(lon,x)*3.1416/180
>> define du = cdiff(u*cos(lat*3.1416/180),y)
>> define dy = cdiff(lat,y)*3.1416/180
>> display (du/dx+dv/dy)/(6.37e6*cos(lat*3.1416/180))
>>
>> Yaqiang Wang
>>
>> Chinese Academy of Meteorological Sciences
>> yaqiang.wang at gmail.com
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
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>
>
>
> --
> Jeff Duda
> Iowa State University
> Meteorology Graduate Student
> 3134 Agronomy Hall
> www.meteor.iastate.edu/~jdduda
>
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