[ncl-talk] Partial derivative along a coordinate

[gibies george]

Thank for your mail.

But the SST case I discussed is just an example.

My actual problem is to get zonal, meridional and vertical gradient of
ocean temperature profile (4D data with time).

I also have to get time tendency of temperature.

That is why I put a generalized mail initially.

Thank and regards

On Apr 17, 2017 6:46 PM, "Dennis Shea" <shea at ucar.edu> wrote:

> NCL has functions to calculate gradients (derivatives).
>
> Your original post did not show that  you wanted gradients of SST.
> Presumably, these have missing values (land).
>  *ftcurvd *will compute gradients but, as noted in the documentation, it
> does not allow missing values.
>
> NCL has other functions for gradients:
>
>    http://www.ncl.ucar.edu/Applications/gradients.shtml
>
> Some use spherical harmonics which are "highly accurate"  but, again, do
> not allow for missing values.
>
> --
> The following 6.4.0 function does allow for missing values.
>
>   http://www.ncl.ucar.edu/Document/Functions/Contributed/grad_latlon_cfd.
> shtml
>
> Read the documentation. This returns a variable of type 'list.' The list
> (container) consists of two variables the zonal and meridional gradients.
> ---
> The following is essentially Example 2:
>
>    fsst = addfile("....","r")
>    sst  = f->SST                        ; assume a rectilinear grid
>
>  sst_grad_list = *grad_latlon_cfd* (sst, sst&lat sst&lon, True, False) ; global
> ;sst_grad_list = *grad_latlon_cfd* (sst, sst&lat sst&lon,False, False) ; regional
>
> ; for clarity, explicitly extract the variables within the list
>
>    sst_grad_zonal     = sst_grad_list[0]      ; [...] is NCL syntax for
> accessing elements of a list
>    sst_grad_meriod   = sst_grad_list[1]
>    delete(sst_grad_list)
>
>    printVarSummary(sst_grad_zonal)
>    printMinMax(sst_grad_zonal,0)
>    print("---")
>    printVarSummary(sst_grad_meriod)
>    printMinMax(sst_grad_meriod,0)
>
>
> Good luck
>
> On Mon, Apr 17, 2017 at 4:01 AM, gibies george <gibies at tropmet.res.in>
> wrote:
>
>> Thanks for your mail.
>>
>> Suppose if I have to calculate zonal gradient of SST(time|:,lat|:,lon|:)
>>
>> xcoord=confirm(*dimsizes*
>> <https://www.ncl.ucar.edu/Document/Functions/Built-in/dimsizes.shtml>
>> (SST),SST&lon,2)
>> dsst_dx = *ftcurvd*(xcoord,SST,SST&lon)
>>
>> Is this correct ?
>>
>>
>>
>>
>> *Dr. Gibies George,*
>> *Project Scientist C,*
>> *Monsoon Mission,*
>>
>> *Indian Institute of Tropical Meteorology,Dr. Homi Bhabha Road, *
>> *NCL Post Office, *
>>
>>
>>
>>
>>
>>
>> *Pashan, Pune 411008, India.Office Teleph  : +912025904423
>> <+91%2020%202590%204423>Office mail      : gibies at tropmet.res.in
>> <gibies at tropmet.res.in>____________________________________________Vettikuzhiyil
>> House,Ezhakkaranadu South **Post Office,*
>>
>>
>>
>> *Puthencruz-682308, Kochi, India.Mobile number :  +919028523910
>> <+91%2090285%2023910>, +919420407392 <+91%2094204%2007392>, Personal mail :
>> gibiesgeorge at gmail.com
>> <gibiesgeorge at gmail.com>http://sites.google.com/site/gibiesge/
>> <http://sites.google.com/site/gibiesge/>*
>>
>>
>> *_______________________________________________________"Please do not
>> print this e-mail unless you really need. Because every 3000 pages cost a
>> tree. *
>> *Save Trees, Save mother Earth." *
>>
>>
>> On 13 April 2017 at 20:31, Andy <awmiller at mit.edu> wrote:
>>
>>> Yes, you can use ftcurvd.
>>>
>>> Andy
>>>
>>> Andy Miller
>>> MIT PAOC PhD Candidate
>>>
>>> 77 Massachusetts Ave | 54-1715
>>> Cambridge, MA 02139
>>>
>>> Phone: 617-253-3715 <(617)%20253-3715>
>>> Email: awmiller at mit.edu
>>>
>>> On 04/13/2017 02:46 AM, gibies george wrote:
>>>
>>> Dear friends,
>>>
>>> Is there a function available to find partial derivative of a variable
>>> along one of its coordinate (say, lonx, laty, levz, time, etc ) ?
>>>
>>> thanks and regards
>>>
>>>
>>> *Dr. Gibies George,*
>>> *Project Scientist C,*
>>> *Monsoon Mission,*
>>>
>>> *Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, *
>>> *NCL Post Office, *
>>>
>>>
>>>
>>>
>>>
>>>
>>> *Pashan, Pune 411008, India. Office Teleph  : +912025904423
>>> <020%202590%204423> Office mail      : gibies at tropmet.res.in
>>> <gibies at tropmet.res.in> ____________________________________________
>>> Vettikuzhiyil House, Ezhakkaranadu South **Post Office,*
>>>
>>>
>>>
>>> * Puthencruz-682308, Kochi, India. Mobile number :  +919028523910
>>> <090285%2023910>, +919420407392 <094204%2007392>,  Personal mail :
>>> gibiesgeorge at gmail.com <gibiesgeorge at gmail.com>
>>> http://sites.google.com/site/gibiesge/
>>> <http://sites.google.com/site/gibiesge/>*
>>>
>>>
>>> *_______________________________________________________ "Please do not
>>> print this e-mail unless you really need. Because every 3000 pages cost a
>>> tree. *
>>> *Save Trees, Save mother Earth." *
>>>
>>>
>>>
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