[ncl-talk] Extracting data for a given point from a model output
Setareh Rahimi
setareh.rahimi at gmail.com
Wed Dec 30 08:15:06 MST 2020
Dear Dennis,
Thanks again for your guide. However, after running the code I noticed tha
t Y = f->emflx(NT,n,m) does not return the value of the emflx variable
for the desired point (lat/lon).
May I ask you please to give me more advice in this regard?
Best wishes,
On Tue, Dec 29, 2020 at 3:22 AM Dennis Shea <shea at ucar.edu> wrote:
> I think we have been through this before. There are many *time/date
> functions.* <https://www.ncl.ucar.edu/Document/Functions/date.shtml>
>
> time = f->time ; hours since 1949-12-01 00:00:00 UTC"
> ; [1]
> TIME = *cd_calendar*
> <https://www.ncl.ucar.edu/Document/Functions/Built-in/cd_calendar.shtml>(time,
> 0) ; PLEASE read the documentation
> year = toint( TIME(:,0) ) ; toint strips meta data
> month = toint( TIME(:,1) )
> day = toint( TIME(:,2) ) ; day of month
> hour = toint( TIME(:,3) ) ; hour of day
> minute = toint( TIME(:,4) )
> second = toint( TIME(:,5) )
>
>
> ;[2]
> ymdh = *yyyymmddhh_time*
> <https://www.ncl.ucar.edu/Document/Functions/Contributed/yyyymmddhh_time.shtml>(time,
> -3) ; PLEASE read the documentation
>
> YMDH = 2019010300
> nt =* ind*
> <https://www.ncl.ucar.edu/Document/Functions/Built-in/ind.shtml>(ymdh
> .eq. YMDH)
> ================================================================
> A simple script is attached.
> ================================================================
>
> %> ncl setareh.ncl
>
> Please Look-at/READ the documentation of the functions used
>
> On Mon, Dec 28, 2020 at 3:04 PM Setareh Rahimi <setareh.rahimi at gmail.com>
> wrote:
>
>>
>> Dear Dennis,
>> I am not looking for interpotation, temperature was just an example.
>> Emflx is one of the varibles in the file. I need to know for say
>> Jan-03-00:00UTC , what is the value of emflx for a specific point .
>> Best wishes,
>> On Tue, Dec 29, 2020 at 01:23 Dennis Shea <shea at ucar.edu> wrote:
>>
>>> As noted by Eshan, you want interpolation.
>>> Please read the documentation for *rcm2points_Wrap* <https://www.ncl.ucar.edu/Document/Functions/Contributed/rcm2points_Wrap.shtml>
>>>
>>> Note: Temperature is NOT in the file.
>>>
>>>
>>> f = *addfile* <https://www.ncl.ucar.edu/Document/Functions/Built-in/addfile.shtml>("Yazd-2019_DUST01.2019010100.nc" , "r")
>>> lat2d = f->xlat
>>> lon2d = f->xlon
>>>
>>> *printVarSummary* <https://www.ncl.ucar.edu/Document/Functions/Built-in/printVarSummary.shtml>(lat2d)
>>> *printMinMax* <https://www.ncl.ucar.edu/Document/Functions/Contributed/printMinMax.shtml>(lat2d, 0)
>>> *printMinMax* <https://www.ncl.ucar.edu/Document/Functions/Contributed/printMinMax.shtml>(lon2d, 0)
>>>
>>> stalat = 32.0 ;(/ 32.0 , 17.31, 24.05 /) ; user specified coordinate pairs
>>> stalon = 52.0 ; (/ 52.0 ,-101.00,-92.46 /)
>>>
>>> X = f->mixrat ; (time, kz, iy, jx)
>>> Y = d->ddflx ; (time, iy, jx)
>>>
>>> x = *rcm2points_Wrap* <https://www.ncl.ucar.edu/Document/Functions/Contributed/rcm2points_Wrap.shtml>(lat2d, lon2d, X, stalat, stalon, 0)
>>> y = *rcm2points_Wrap* <https://www.ncl.ucar.edu/Document/Functions/Contributed/rcm2points_Wrap.shtml>(lat2d, lon2d, Y, stalat, stalon, 0)
>>>
>>> print(x)
>>>
>>> print(y)
>>>
>>>
>>> On Mon, Dec 28, 2020 at 12:10 PM Setareh Rahimi <
>>> setareh.rahimi at gmail.com> wrote:
>>>
>>>> Dear Dennis,
>>>> Many thanks for your response. What I exactly mean is how to extract
>>>> for example "Temperature variable" value for a specific lat/lon from the
>>>> output result. For example: what is temperature value for a point at
>>>> (lat=32, lon 52)?
>>>> Thanks again
>>>> Best wishes
>>>>
>>>> On Mon, Dec 28, 2020 at 10:17 PM Dennis Shea <shea at ucar.edu> wrote:
>>>>
>>>>> *getind_latlon2d *
>>>>> <https://www.ncl.ucar.edu/Document/Functions/Contributed/getind_latlon2d.shtml>
>>>>>
>>>>> A modification of Example 1
>>>>>
>>>>> f = *addfile* <https://www.ncl.ucar.edu/Document/Functions/Built-in/addfile.shtml>("Yazd-2019_DUST01.2019010100.nc" , "r")
>>>>> lat2d = f->xlat
>>>>> lon2d = f->xlon
>>>>>
>>>>> *printVarSummary* <https://www.ncl.ucar.edu/Document/Functions/Built-in/printVarSummary.shtml>(lat2d)
>>>>> *printMinMax* <https://www.ncl.ucar.edu/Document/Functions/Contributed/printMinMax.shtml>(lat2d, 0)
>>>>> *printMinMax* <https://www.ncl.ucar.edu/Document/Functions/Contributed/printMinMax.shtml>(lon2d, 0)
>>>>>
>>>>> lat = (/ 31.0 , 17.31, 24.05 /) ; user specified coordinate pairs
>>>>> lon = (/ -86.45,-101.00,-92.46 /)
>>>>> ; return 2d subscripts
>>>>> nm = *getind_latlon2d* (lat2d,lon2d, lat, lon)
>>>>>
>>>>> *print* <https://www.ncl.ucar.edu/Document/Functions/Built-in/print.shtml>(nm)
>>>>>
>>>>> X = f->mixrat ; (time, kz, iy, jx)
>>>>> Y = d->ddflx ; (time, iy, jx)
>>>>>
>>>>> nt = .... the index some specified time
>>>>>
>>>>> kl = ... index
>>>>>
>>>>> do k=0,*dimsizes* <https://www.ncl.ucar.edu/Document/Functions/Built-in/dimsizes.shtml>(lat)-1
>>>>> n = nm(k,0)
>>>>> m = nm(k,1)
>>>>>
>>>>> x = X(nt,kl,n,m)
>>>>> y = Y(nt,n,m)
>>>>>
>>>>> *print* <https://www.ncl.ucar.edu/Document/Functions/Built-in/print.shtml>(lat2d(n,m)+" "+lon2d(n,m)+" "+x+" "+y)
>>>>> end do
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Mon, Dec 28, 2020 at 10:16 AM Setareh Rahimi via ncl-talk <
>>>>> ncl-talk at mailman.ucar.edu> wrote:
>>>>>
>>>>>> Dear all,
>>>>>>
>>>>>> I need to extract data (it could be any variable like temperature,
>>>>>> wind ...) for a specific point (say synoptic stations) at a specific day
>>>>>> and time
>>>>>> Yazd-2019_DUST01.2019010100.nc
>>>>>> <https://drive.google.com/file/d/105vU4Hx2sRjvWlsmRBKOxa97kXp8Cx1_/view?usp=drive_web>
>>>>>> ( Jan-03- 00:00 UTC), from a model output (file attached). I wonder
>>>>>> how it could be achieved using NCL (any example...) .
>>>>>>
>>>>>> I appreciate any suggestion,
>>>>>> Best wishes,
>>>>>> --
>>>>>> S.Rahimi
>>>>>>
>>>>>> _______________________________________________
>>>>>> ncl-talk mailing list
>>>>>> ncl-talk at mailman.ucar.edu
>>>>>> List instructions, subscriber options, unsubscribe:
>>>>>> https://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>>
>>>>>
>>>>
>>>> --
>>>> S.Rahimi
>>>>
>>>> --
>> S.Rahimi
>>
>>
--
S.Rahimi
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