[ncl-talk] Extracting data for a given point from a model output

Setareh Rahimi setareh.rahimi at gmail.com
Wed Dec 30 11:39:12 MST 2020


That attached was 'dry deposition flux', please ignore that, and have a
look at the attached file.
Thanks,

On Wed, Dec 30, 2020 at 10:01 PM Setareh Rahimi <setareh.rahimi at gmail.com>
wrote:

> Dear Dennis,
> This is something weird to me, too.I attached a plot of output model for
> the same date. Comparing  the plot with the value for that lat/lon, results
> do not match together. What is your idea?
> Many thanks again,
> Best wishes,
>
> On Wed, Dec 30, 2020 at 7:09 PM Dennis Shea <shea at ucar.edu> wrote:
>
>> ????  does not return the value of the emflx variable for the desired
>> point (lat/lon)
>>
>> Well, what is the "correct value" ?
>> ======
>>
>>   lat = 32.0
>>   lon = 52.0
>>
>> (0) ==================
>> (0) n=21   m=8   lat2d(n,m)=31.9429   lon2d(n,m)=51.921   *<====This is
>> the closest grid point ... pretty close!!!*
>> (0) ==================
>>
>> (5) 605628   ymdh=2019010212
>> (6) 605634   ymdh=2019010218
>> *(7)* 605640   ymdh=*2019010300    <===  NT=7*
>> (8) 605646   ymdh=2019010306
>> (9) 605652   ymdh=2019010312
>>
>>   *YMDH   = 2019010300 *            ; user specified
>>   print("YMDH="+YMDH)
>>   NT     = ind(ymdh .eq. YMDH)
>>   print("NT="+NT+" ymdh(NT)="+ymdh(NT) )
>>
>>
>> *(0) YMDH=2019010300(0) NT=7 ymdh(NT)=2019010300*
>> (0) ==================
>>
>>   EMFLX = f->emflx
>>   emflx = EMFLX(NT,n,m)           ; scalar
>>   print("==================")
>>   print( emflx )                 ;  ====
>>
>> (0) 940.5043
>>
>> On Wed, Dec 30, 2020 at 8:15 AM Setareh Rahimi <setareh.rahimi at gmail.com>
>> wrote:
>>
>>> Dear Dennis,
>>> Thanks again for your guide. However, after running the code I noticed
>>> that  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
>>>
>>>
>
> --
> S.Rahimi
>
>

-- 
S.Rahimi
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