[ncl-talk] grid_area_avg
Barry Lynn
barry.h.lynn at gmail.com
Wed Oct 25 04:16:07 MDT 2017
Kunal:
Why don't you extract the grid elements you want and then use the NCL
average function to find the mean of those grid points? You can extract a
grid of the size you want or just the points.
Barry
On Wed, Oct 25, 2017 at 10:07 AM, Kunal Bali <kunal.bali9 at gmail.com> wrote:
> Thanks for the information. I did not include the time variable. So
>
> I changed aot_subset(ilt1:ilt2,iln1:iln2) = data(ilt1:ilt2,iln1:iln2) to
> aot_subset(*:,*ilt1:ilt2,iln1:iln2) = data(*:,*ilt1:ilt2,iln1:iln2)
>
> AND it worked.
>
>
> But from the given script, I am not getting the mean value of the grid
> box. It producing the values of every grid separately. As given below
>
> (0) 22.17971308103524 69.17124237598317
> (0) -28672
> (1) 0.208
> (0) -----
> (0) 24.55800304046942 79.47472902537179
> (0) -28672
> (1) -28672
> (0) -----
>
>
> I need to extract the data of square box and mean it. so that I can get
> the values with every time steps.
>
> latv = (/ 13, 25/) ; for extracting grid box data
> lonv = (/ 72, 85 /)
>
> The script is
>
>
> ;----------------------------------------------------------------------
> ; Main code
> ;----------------------------------------------------------------------
> dir = "./"
> fnames = systemfunc("ls " + dir + "maiactaot*.nc")
> print(fnames)
> a = addfile(fnames,"r")
> data = short2flt(a->Optical_Depth_055_grid1km)
> printVarSummary (data)
> printMinMax (data, 0)
> print("-----")
> nFill = num(ismissing(data))
> print("nFill="+nFill)
> print("-----")
>
> lat2d = a->GridLat_grid1km
> lon2d = a->GridLon_grid1km
> printMinMax (lat2d, 0)
> printMinMax (lon2d, 0)
> print("-----")
>
> ;---grid points of interest
> ;---http://www.ncl.ucar.edu/Document/Functions/
> Contributed/getind_latlon2d.shtml
> ; latv = (/22, 24.0, 24.0, 22.0, 22.0/)
> ; lonv = (/76, 76.0, 78.0, 78.0, 76.0/)
>
> latv = (/ 13, 25/) ; for extracting grid box data
> lonv = (/ 72, 85 /)
> nm = getind_latlon2d (lat2d, lon2d, latv, lonv)
> ilt1 = nm(0,0) ; start lat index
> ilt2 = nm(1,0) ; start lon index
> iln1 = nm(0,1) ; end lat index
> iln2 = nm(1,1) ; end lon index
> lat_subset = lat2d(ilt1:ilt2,iln1:iln2)
> lon_subset = lon2d(ilt1:ilt2,iln1:iln2)
> aot_subset := data
> aot_subset = aot_subset at _FillValue
> aot_subset(:,ilt1:ilt2,iln1:iln2) = data(:,ilt1:ilt2,iln1:iln2)
>
>
>
> printVarSummary(aot_subset)
> print("ilt1 = " + ilt1)
> print("ilt2 = " + ilt2)
> print("iln1 = " + iln1)
> print("iln2 = " + iln2)
>
> ; aot_avg = avg(data)
> aot_subset_avg = avg(data)
>
> ;print(nm)
> print("-----")
>
> do k=0,dimsizes(latv)-1
> n = nm(k,0)
> m = nm(k,1)
> print(lat2d(n,m)+" "+lon2d(n,m))
> print(" "+data(:,n,m)) ; nearest grid point at
> all time steps
> print("-----")
> end do
>
>
>
>
>
>
> Kunal Bali
>
>
>
>
>
> On Wed, Oct 25, 2017 at 12:25 PM, Barry Lynn <barry.h.lynn at gmail.com>
> wrote:
>
>> Kunal:
>>
>> The error message says that you have used three subscripts on a variables
>> with only two dimensions.
>>
>> You need to fix this error for your script to proceed to the next step.
>>
>> Barry
>>
>> On Wed, Oct 25, 2017 at 8:59 AM, Kunal Bali <kunal.bali9 at gmail.com>
>> wrote:
>>
>>> It also shows an error if I replaced := with = in 38 line of the given
>>> script (attached earlier), even though variable is in 2D array.
>>>
>>> fatal:["Execute.c":7950]:Number of subscripts on right-hand-side do not
>>> match
>>> number of dimensions of variable: (2), Subscripts used: (3)
>>>
>>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 38 in
>>> file extract1.ncl
>>>
>>>
>>>
>>> Kunal Bali
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Tue, Oct 24, 2017 at 4:46 PM, Helen Macintyre <
>>> Helen.Macintyre at phe.gov.uk> wrote:
>>>
>>>> You are trying to delete a variable that has not been assigned.
>>>>
>>>>
>>>>
>>>> Using “:=” tries to delete aot_subset when it doesn’t exist yet.
>>>>
>>>>
>>>>
>>>> More info here:
>>>>
>>>> http://www.ncl.ucar.edu/Document/Language/varb_assign.shtml
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *From:* ncl-talk [mailto:ncl-talk-bounces at ucar.edu] *On Behalf Of *Kunal
>>>> Bali
>>>> *Sent:* 24 October 2017 06:28
>>>> *To:* ncl-talk at ucar.edu
>>>> *Subject:* Re: [ncl-talk] grid_area_avg
>>>>
>>>>
>>>>
>>>> I am not able to sort out the query regarding
>>>>
>>>> fatal:Variable (aot_subset) is undefined
>>>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 38 in
>>>> file extract1.ncl
>>>>
>>>> I have attached my script. please let me know how to solve it (the file
>>>> regarding this script is attached in the previous mail).
>>>>
>>>>
>>>>
>>>> sorry for the inconvenience*. *
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> regards
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Sat, Oct 21, 2017 at 1:53 PM, Kunal Bali <kunal.bali9 at gmail.com>
>>>> wrote:
>>>>
>>>> thanks for providing this information. I am positive that the given
>>>> variable in the data is a 2D array and the error is coming on 38 line as I
>>>> mentioned earlier.
>>>>
>>>> I am trying to debug this problem accordingly as you mentioned.
>>>>
>>>> However, I have attached the data (size =30mb, tried via ftp but facing
>>>> some error while uploading) and the full script for extracting the grid box
>>>> mean value.
>>>>
>>>>
>>>>
>>>> Thank You for all the support.
>>>>
>>>>
>>>>
>>>> * maiactaot.h00v02.20010040635-20011550640.nc.bz2
>>>> <https://drive.google.com/file/d/0B6MS-JLMHECwaVh3QVVHUU1Wazg/view?usp=drive_web>*
>>>>
>>>>
>>>>
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Fri, Oct 20, 2017 at 9:14 PM, Mary Haley <haley at ucar.edu> wrote:
>>>>
>>>> Kunal,
>>>>
>>>>
>>>>
>>>> Multiple people have tried to help you, but you continue to post error
>>>> messages without trying to debug them yourself. If you don't make an
>>>> effort, people are likely to stop trying to help. You are including code
>>>> snippets, but this is not always enough for us to help you debug the
>>>> problem. You need to include full scripts, output from
>>>> print/printVarSummary commands, AND all error messages.
>>>>
>>>>
>>>>
>>>> For example, you originally included this code:
>>>>
>>>>
>>>>
>>>> latv = (/ 18, 24/) ; for extracting grid box data
>>>>
>>>> lonv = (/ 74, 78 /)
>>>>
>>>> nm = getind_latlon2d (lat2d, lon2d, latv, lonv)
>>>>
>>>> ilt1 = nm(0,0) ; start lat index
>>>>
>>>> ilt2 = nm(1,0) ; start lon index
>>>>
>>>> iln1 = nm(0,1) ; end lat index
>>>>
>>>> iln2 = nm(1,1) ; end lon index
>>>>
>>>> lat_subset := lat2d(ilt1:ilt2,iln1:iln2)
>>>>
>>>> lon_subset := lon2d(ilt1:ilt2,iln1:iln2)
>>>>
>>>> aot_subset := data
>>>>
>>>> aot_subset(ilt1:ilt2,iln1:iln2) := data(ilt1:ilt2, iln1:iln2)
>>>>
>>>>
>>>>
>>>> ;printVarSummary(aot_subset)
>>>>
>>>> aot_avg = avg(data)
>>>>
>>>> aot_subset_avg = avg(aot_subset)
>>>>
>>>>
>>>>
>>>> and then said that you were getting an error about aot_subset being
>>>> undefined. From the perspective of somebody who is just looking at the code
>>>> snippet above and doesn't have access to your full script, we are going to
>>>> wonder about this line:
>>>>
>>>>
>>>>
>>>> aot_subset := data
>>>>
>>>>
>>>>
>>>> Since this appears to be the first time aot_subset is set, our next
>>>> question is going to be "is data defined"? In the code snippet you
>>>> included, we don't see where "data" is defined, so we have no way to help.
>>>> This is where a "printVarSummary(data)" line would have helped.
>>>>
>>>>
>>>>
>>>> In your last email, in which you did include some information about
>>>> "data", things are still not making any sense. You said you were subsetting
>>>> data as a 2D array with:
>>>>
>>>>
>>>>
>>>> aot_subset(ilt1:ilt2,iln1:iln2) = data(ilt1:ilt2,iln1:iln2)
>>>>
>>>>
>>>>
>>>> which you said was causing this error:
>>>>
>>>>
>>>>
>>>> fatal:["Execute.c":7950]:Number of subscripts on right-hand-side do
>>>> not match
>>>>
>>>> number of dimensions of variable: (2), Subscripts used: (3)
>>>>
>>>>
>>>>
>>>> This error doesn't seem possible, because it's saying that you are
>>>> using 3 subscripts, but the line only has 2 subscripts being used in both
>>>> arrays. Are you positive that this error is coming from this line?
>>>>
>>>>
>>>>
>>>> I have to ask you again to please include your *full script* next time
>>>> and *all error messages* and *all printed output*, so people can see
>>>> exactly what line numbers in your script the errors correspond with and
>>>> what your data looks like. But don't do this until you have shown that you
>>>> tried to debug the problem yourself. Use "print" and "printVarSummary"
>>>> *before* the locations where the error messages are occurring, so you can
>>>> see what might be causing the error.
>>>>
>>>>
>>>>
>>>> For example, if the error says
>>>>
>>>>
>>>>
>>>> number of dimensions of variable: (2), Subscripts used: (3)
>>>>
>>>>
>>>>
>>>> then this means you are subscripting a variable as if it were a 2D
>>>> array, when it is actually a 3D array. Add *printVarSummary*
>>>> statements on ALL subscripted variables that occur in that line, so you can
>>>> be sure you are doing things correctly. For example, if the error occurs
>>>> on this line:
>>>>
>>>>
>>>>
>>>> aot_subset(ilt1:ilt2,iln1:iln2) := data(ilt1:ilt2, iln1:iln2)
>>>>
>>>>
>>>>
>>>> then do this:
>>>>
>>>>
>>>> printVarSummary(data)
>>>>
>>>> printVarSummary(aot_subset)
>>>>
>>>> aot_subset(ilt1:ilt2,iln1:iln2) := data(ilt1:ilt2, iln1:iln2)
>>>>
>>>>
>>>>
>>>> It may also help to print the il* variables:
>>>>
>>>>
>>>>
>>>> printVarSummary(data)
>>>>
>>>> printVarSummary(aot_subset)
>>>>
>>>> print("ilt1 = " + ilt1)
>>>>
>>>> print("ilt2 = " + ilt2)
>>>>
>>>> print("iln1 = " + iln1)
>>>>
>>>> print("iln2 = " + iln2)
>>>>
>>>> aot_subset(ilt1:ilt2,iln1:iln2) := data(ilt1:ilt2, iln1:iln2)
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Moving forward, you *must* show that you are making some effort to
>>>> debug your problem.
>>>>
>>>>
>>>>
>>>> Thank you for your consideration.
>>>>
>>>>
>>>>
>>>> --Mary
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Oct 18, 2017 at 12:23 AM, Kunal Bali <kunal.bali9 at gmail.com>
>>>> wrote:
>>>>
>>>> printVarSummary(aot_subset), shows that aot_subset is undefined, which
>>>> I am unable to fix this problem yet.
>>>>
>>>> If I used aot_subset(ilt1:ilt2,iln1:iln2) *=*
>>>> data(ilt1:ilt2,iln1:iln2) *instead of *aot_subset(ilt1:ilt2,iln1:iln2)
>>>> *:=* data(ilt1:ilt2,iln1:iln2)
>>>>
>>>>
>>>> then the error appeared as
>>>>
>>>>
>>>> *fatal:["Execute.c":7950]:Number of subscripts on right-hand-side do
>>>> not match number of dimensions of variable: (2), Subscripts
>>>> used: (3)*
>>>>
>>>> basically, the data summary is
>>>>
>>>> Variable: fnames
>>>> Type: string
>>>> Total Size: 8 bytes
>>>> 1 values
>>>> Number of Dimensions: 1
>>>> Dimensions and sizes: [1]
>>>> Coordinates:
>>>> (0) ./maiactaotE.h00v03.20000550525-20003660700.nc
>>>>
>>>> Variable: data
>>>> Type: float
>>>> Total Size: 2545920000 <(254)%20592-0000> bytes
>>>> 636480000 values
>>>> Number of Dimensions: 3
>>>> Dimensions and sizes: *[time | 442] x [YDim_grid1km | 1200] x
>>>> [XDim_grid1km | 1200]*
>>>> Coordinates:
>>>> time: [1301.416666666686..8767]
>>>> Number Of Attributes: 8
>>>> coordinates : GridLat_grid1km, GridLon_grid1km
>>>> hdfeos_name : Optical_Depth_055
>>>> projection : Albers Conical Equal_Area
>>>> unit : None
>>>> long_name : AOT at 0.55 micron
>>>> _FillValue_original : -28672
>>>> _FillValue : -28672
>>>> valid_range : ( -0.1, 5 )
>>>> (0) latitude (degrees_north) : min=11.2940312768897
>>>> max=24.54921980985786
>>>> (0) longitude (degrees_east) : min=68.08003670367275
>>>> max=81.63171349927691
>>>>
>>>> *fatal:["Execute.c":7776]:aot_subset is undefined, can not subscript an
>>>> undefined variable fatal:["Execute.c":8640]:Execute: Error occurred at or
>>>> near line 38 in file test_extract.ncl*
>>>>
>>>> *38 line is *
>>>> *aot_subset(ilt1:ilt2,iln1:iln2) = data(ilt1:ilt2,iln1:iln2)*
>>>>
>>>> *fatal:Variable (aot_subset) is undefined*
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> regards
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Tue, Oct 17, 2017 at 3:05 PM, Guido Cioni <guidocioni at gmail.com>
>>>> wrote:
>>>>
>>>> Why did you comment this line ?
>>>>
>>>>
>>>>
>>>> ;printVarSummary(aot_subset)
>>>>
>>>>
>>>>
>>>> That would have helped you in debugging the error on your own.
>>>>
>>>>
>>>>
>>>> You are using the re-assignment operator ":=". This means that every
>>>> time you make an assignment the variable is created again. Thus, you cannot
>>>> make this assignment
>>>>
>>>>
>>>>
>>>> * aot_subset(ilt1:ilt2,iln1:iln2) := data(ilt1:ilt2, iln1:iln2)*
>>>>
>>>>
>>>>
>>>> as NCL has no way to know the shape of aot_subset beforehand.
>>>>
>>>>
>>>>
>>>> The following should be used instead (notice the assignment with "=" in
>>>> the second line).
>>>>
>>>>
>>>>
>>>> aot_subset := data
>>>>
>>>> aot_subset = aot_subset at _FillValue
>>>> aot_subset(ilt1:ilt2,iln1:iln2) *=* data(ilt1:ilt2, iln1:iln2)
>>>>
>>>>
>>>>
>>>> Notice that this will (1) create an array which is shaped like data (2)
>>>> fill it with fill values as you only want to compute the average over the
>>>> subset (3) populate the array only in the lat-lon box provided. However I
>>>> don't see why you would want to use such a complicated syntax when the
>>>> following code would produce the same result
>>>>
>>>>
>>>>
>>>> aot_subset_avg=avg(data(ilt1:ilt2, iln1:iln2))
>>>>
>>>>
>>>>
>>>> If you have the right coordinate attributes you can even jump the first
>>>> 7 lines and do
>>>>
>>>>
>>>>
>>>> aot_subset_avg=avg(data({18:24},{74:78})
>>>>
>>>>
>>>>
>>>> but I don't know your data.
>>>>
>>>>
>>>>
>>>> As it was already suggested by Mary and others, PLEASE take time to
>>>> debug the errors on your own.
>>>>
>>>>
>>>>
>>>> Regards,
>>>>
>>>>
>>>>
>>>> On 17. Oct 2017, at 11:25, Kunal Bali <kunal.bali9 at gmail.com> wrote:
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> I did the following changes but still getting an error of * aot_subset*
>>>> which is undefined.
>>>>
>>>> please let me know that how to fix or defined the *aot_subset *this
>>>> problem.
>>>>
>>>>
>>>>
>>>>
>>>> latv = (/ 18, 24/) ; for extracting grid box data
>>>> lonv = (/ 74, 78 /)
>>>> nm = getind_latlon2d (lat2d, lon2d, latv, lonv)
>>>> ilt1 = nm(0,0) ; start lat index
>>>> ilt2 = nm(1,0) ; start lon index
>>>> iln1 = nm(0,1) ; end lat index
>>>> iln2 = nm(1,1) ; end lon index
>>>> lat_subset := lat2d(ilt1:ilt2,iln1:iln2)
>>>> lon_subset := lon2d(ilt1:ilt2,iln1:iln2)
>>>> aot_subset := data
>>>> * aot_subset(ilt1:ilt2,iln1:iln2) := data(ilt1:ilt2, iln1:iln2)*
>>>>
>>>> ;printVarSummary(aot_subset)
>>>> aot_avg = avg(data)
>>>> aot_subset_avg = avg(*aot_subset*)
>>>>
>>>> ;print(nm)
>>>> print("-----")
>>>>
>>>> do k=0,dimsizes(latv)-1
>>>> n = nm(k,0)
>>>> m = nm(k,1)
>>>> print(lat2d(n,m)+" "+lon2d(n,m))
>>>> print(" "+data(:,n,m)) ; nearest grid point
>>>> at all time steps
>>>> print("-----")
>>>> end do
>>>>
>>>>
>>>>
>>>>
>>>> regards
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Tue, Oct 17, 2017 at 12:41 PM, Kunal Bali <kunal.bali9 at gmail.com>
>>>> wrote:
>>>>
>>>> I have sent the ncl script and data to the incoming dir with the given
>>>> names as
>>>>
>>>> data = maiactaotE.h00v03.20003660525-20003660700.nc.bz2
>>>>
>>>> ncl_script = extract_iiserb.ncl
>>>>
>>>>
>>>>
>>>> I am not able to define the var_subset in the given script.
>>>>
>>>> please let me know if you have received the data and script?
>>>>
>>>>
>>>>
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Mon, Oct 16, 2017 at 11:07 PM, Mary Haley <haley at ucar.edu> wrote:
>>>>
>>>> Kunal,
>>>>
>>>>
>>>>
>>>> You must make an effort to debug some of these problems on your own.
>>>> The error is telling you that something is wrong around line 34 and it is
>>>> telling you exactly what the problem is. Please try to fix this error.
>>>>
>>>>
>>>>
>>>> If you continue to have problems after fixing this error, then I need
>>>> to ask you to provide the full script and data via ftp:
>>>>
>>>>
>>>>
>>>> http://www.ncl.ucar.edu/ftp_files.shtml
>>>>
>>>>
>>>>
>>>> However, make sure you debug any other new problems that come up,
>>>> instead of just emailing them to ncl-talk. We have a page to help you
>>>> understand some of NCL's errors, and what causes them:
>>>>
>>>>
>>>>
>>>> http://www.ncl.ucar.edu/Document/Language/error_messages.shtml
>>>>
>>>>
>>>>
>>>> The particular error you're seeing can be found here:
>>>>
>>>>
>>>>
>>>> http://www.ncl.ucar.edu/Document/Language/error_messages.sht
>>>> ml#NumSubRHS
>>>>
>>>>
>>>>
>>>> As a side note, you are running a 3-year old version of NCL. I suggest
>>>> that you upgrade to NCL V6.4.0.
>>>>
>>>>
>>>>
>>>> --Mary
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Mon, Oct 16, 2017 at 12:52 AM, Kunal Bali <kunal.bali9 at gmail.com>
>>>> wrote:
>>>>
>>>> I simply include the code (which you mentioned) were I was taking the
>>>> avg of the data as given below (please correct me if I did wrong)
>>>>
>>>>
>>>> ;----------------------------------------------------------------------
>>>> ; Main code
>>>> ;----------------------------------------------------------------------
>>>> dir = "./"
>>>> fnames = systemfunc("ls " + dir + "maiactaot*.nc")
>>>> print(fnames)
>>>> a = addfile(fnames,"r")
>>>> data = short2flt(a->Optical_Depth_055_grid1km)
>>>> printVarSummary (data)
>>>> printMinMax (data, 0)
>>>> print("-----")
>>>> nFill = num(ismissing(data))
>>>> print("nFill="+nFill)
>>>> print("-----")
>>>>
>>>> lat2d = a->GridLat_grid1km
>>>> lon2d = a->GridLon_grid1km
>>>> printMinMax (lat2d, 0)
>>>> printMinMax (lon2d, 0)
>>>> print("-----")
>>>>
>>>> ;---grid points of interest
>>>> ;---http://www.ncl.ucar.edu/Document/Functions/Contributed/g
>>>> etind_latlon2d.shtml
>>>> ; latv = (/22, 24.0, 24.0, 22.0, 22.0/)
>>>> ; lonv = (/76, 76.0, 78.0, 78.0, 76.0/)
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *latv = (/ 22, 24/) lonv = (/ 76, 78 /) nm = getind_latlon2d
>>>> (lat2d, lon2d, latv, lonv) ilt1 = nm(0,0) ; start lat index ilt2 =
>>>> nm(1,0) ; start lon index iln1 = nm(0,1) ; end lat index iln2 =
>>>> nm(1,1) ; end lon index var_subset = var(ilt1:ilt2,iln1:iln2)
>>>> var_subset_avg = avg(var_subset)*
>>>>
>>>> print(nm)
>>>> print("-----")
>>>>
>>>> do k=0,dimsizes(latv)-1
>>>> n = nm(k,0)
>>>> m = nm(k,1)
>>>> print(lat2d(n,m)+" "+lon2d(n,m))
>>>> print(" "+data(:,n,m)) ; nearest grid point
>>>> at all time steps
>>>> print("-----")
>>>> end do
>>>>
>>>>
>>>>
>>>>
>>>> *But still not getting the desired output as a single square box mean
>>>> value . It is showing the errors as*
>>>>
>>>> kunal at kunal-Vostro-1015:/media/Local Disk_/IIT_DELHI/2001/MAIACTAOT_TIME$
>>>> ncl extract1.ncl
>>>> Copyright (C) 1995-2014 - All Rights Reserved
>>>> University Corporation for Atmospheric Research
>>>> NCAR Command Language Version 6.2.1
>>>> The use of this software is governed by a License Agreement.
>>>> See http://www.ncl.ucar.edu/ for more details.
>>>>
>>>>
>>>> Variable: fnames
>>>> Type: string
>>>> Total Size: 4 bytes
>>>> 1 values
>>>> Number of Dimensions: 1
>>>> Dimensions and sizes: [1]
>>>> Coordinates:
>>>> (0) ./maiactaot.h00v02.20010040635-20011550640.nc
>>>>
>>>> Variable: data
>>>> Type: float
>>>> Total Size: 40320000 bytes
>>>> 10080000 values
>>>> Number of Dimensions: 3
>>>> Dimensions and sizes: [time | 7] x [YDim_grid1km | 1200] x
>>>> [XDim_grid1km | 1200]
>>>> Coordinates:
>>>> time: [8862.583333333314..12486.66666666669]
>>>> Number Of Attributes: 8
>>>> coordinates : GridLat_grid1km, GridLon_grid1km
>>>> hdfeos_name : Optical_Depth_055
>>>> projection : Albers Conical Equal_Area
>>>> unit : None
>>>> long_name : AOT at 0.55 micron
>>>> _FillValue_original : -28672
>>>> _FillValue : -28672
>>>> valid_range : ( -0.1, 5 )
>>>> (0) AOT at 0.55 micron: min=0 max=3.924
>>>> (0) -----
>>>> (0) nFill=6285271
>>>> (0) -----
>>>> (0) latitude: min=21.86737357453027 max=34.99855492029426
>>>> (0) longitude: min=64.23634233372005 max=79.4747290253718
>>>> (0) -----
>>>> fatal:["Execute.c":7863]:Number of subscripts on right-hand-side do
>>>> not match
>>>> number of dimensions of variable: (2), Subscripts used: (3)
>>>>
>>>> fatal:["Execute.c":8578]:Execute: Error occurred at or near line 34 in
>>>> file extract1.ncl
>>>>
>>>> fatal:Variable (var_subset) is undefined
>>>> fatal:["Execute.c":8578]:Execute: Error occurred at or near line 35 in
>>>> file extract1.ncl
>>>>
>>>>
>>>>
>>>>
>>>> Variable: nm
>>>> Type: integer
>>>> Total Size: 16 bytes
>>>> 4 values
>>>> Number of Dimensions: 2
>>>> Dimensions and sizes: [2] x [2]
>>>> Coordinates:
>>>> Number Of Attributes: 1
>>>> long_name : indices closest to specified LAT/LON coordinate pairs
>>>> (0,0) 1199
>>>> (0,1) 792
>>>> (1,0) 1199
>>>> (1,1) 1041
>>>> (0) -----
>>>> (0) 23.76603307545667 75.53995171540016
>>>> (0) 0.179
>>>> (1) 0.142
>>>> (2) -28672
>>>> (3) 0.169
>>>> (4) -28672
>>>> (5) -28672
>>>> (6) -28672
>>>> (0) -----
>>>> (0) 24.26559325846936 77.93996773594735
>>>> (0) -28672
>>>> (1) 0.393
>>>> (2) -28672
>>>> (3) 0.156
>>>> (4) 0.313
>>>> (5) -28672
>>>> (6) -28672
>>>> (0) -----
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Sat, Oct 14, 2017 at 12:24 AM, Mary Haley <haley at ucar.edu> wrote:
>>>>
>>>> Kunal,
>>>>
>>>>
>>>>
>>>> Please include the code where you are actually taking the average of
>>>> your data using the information returned from getind_latlon2d.
>>>>
>>>>
>>>>
>>>> It's important to note that getind_latlon2d simply returns the
>>>> individual index values that are closest to each of the lat/lon pairs that
>>>> you gave it. It doesn't work in such a way that you give it a lat/lon box
>>>> and it returns all the values in that box.
>>>>
>>>>
>>>>
>>>> That's what I was trying to illustrate with the wrf_gsn_10.ncl I
>>>> created. I gave the function two corners of the box, and then using the
>>>> two pairs of index values I got back, I was able to get all the values
>>>> inside the box area of interest:
>>>>
>>>>
>>>>
>>>> lats = (/ min_lat, max_lat /)
>>>>
>>>> lons = (/ min_lon, max_lon /)
>>>>
>>>> nm = getind_latlon2d (lat2d, lon2d, lats, lons)
>>>>
>>>> ilt1 = nm(0,0) ; start lat index
>>>>
>>>> ilt2 = nm(1,0) ; start lon index
>>>>
>>>> iln1 = nm(0,1) ; end lat index
>>>>
>>>> iln2 = nm(1,1) ; end lon index
>>>> var_subset = var(ilt1:ilt2,iln1:iln2)
>>>>
>>>> var_subset_avg = avg(var_subset)
>>>>
>>>>
>>>>
>>>> --Mary
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Thu, Oct 12, 2017 at 1:19 PM, Kunal Bali <kunal.bali9 at gmail.com>
>>>> wrote:
>>>>
>>>> Dear Haley Ma'am,
>>>>
>>>>
>>>>
>>>> Thanks for providing the information and example.
>>>>
>>>> But if I follow the getind_latlon2d function as I did, then it seems
>>>> like I followed the same procedure as given in the example
>>>> http://www.ncl.ucar.edu/Document/Functions/Contributed/getin
>>>> d_latlon2d.shtml
>>>>
>>>>
>>>>
>>>> But still I am not getting the mean of the grid box on every time
>>>> step or am I reading incorrectly the result ?
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> regards
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Fri, Oct 13, 2017 at 12:11 AM, Mary Haley <haley at ucar.edu> wrote:
>>>>
>>>> Kunal,
>>>>
>>>>
>>>>
>>>> I created an example for you, showing three ways you can subset a WRF
>>>> grid (since I already had a similar example). It shows how to use the
>>>> getind_latlon2d function.
>>>>
>>>>
>>>>
>>>> You have to be careful with subsetting curvilinear data, because
>>>> specifying a lat/lon box to take an average over can mean two
>>>> different things. You will be able to see the difference when you look at
>>>> the graphic.
>>>>
>>>>
>>>>
>>>> See example wrf_gsn_10.ncl at:
>>>>
>>>>
>>>>
>>>> http://www.ncl.ucar.edu/Applications/wrfgsn.shtml#ex10
>>>>
>>>>
>>>>
>>>> --Mary
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Oct 11, 2017 at 12:03 PM, Kunal Bali <kunal.bali9 at gmail.com>
>>>> wrote:
>>>>
>>>> Dear NCL users,
>>>>
>>>>
>>>> Single point coordinates values of 23.0 N and 77.0 E is extracted or
>>>> print by using the script below
>>>>
>>>> ----------------------------------------------------------------------
>>>> ; Main code
>>>> ;----------------------------------------------------------------------
>>>> dir = "./"
>>>> fnames = systemfunc("ls " + dir + "maiactaot*.nc")
>>>> print(fnames)
>>>> a = addfile(fnames,"r")
>>>> data = short2flt(a->Optical_Depth_055_grid1km)
>>>> nFill = num(ismissing(data))
>>>> lat2d = a->GridLat_grid1km
>>>> lon2d = a->GridLon_grid1km
>>>>
>>>> ;---grid points of interest
>>>> latv = (/23.0/)
>>>> lonv = (/77.0 /)
>>>>
>>>> nm = getind_latlon2d (lat2d,lon2d, latv, lonv)
>>>>
>>>> do k=0,dimsizes(latv)-1
>>>> n = nm(k,0)
>>>> m = nm(k,1)
>>>> print(lat2d(n,m)+" "+lon2d(n,m)) ; grid point location
>>>> print(" "+data(:,n,m)) ; nearest grid point
>>>> at all time steps
>>>> print("-----")
>>>> end do
>>>>
>>>>
>>>> NOW, I want to extract the square grid box of 100 km around the
>>>> coordinates (23N,77E) such as
>>>> latv = (/22, 24.0, 24.0, 22.0, 22.0/)
>>>> lonv = (/76, 76.0, 78.0, 78.0, 76.0 /)
>>>>
>>>>
>>>> after that I want to do the area mean of the grid box. So that I can
>>>> get one single point value of that grid box.
>>>>
>>>> So when I replacing
>>>> latv = (/23.0/)
>>>> lonv = (/77.0/)
>>>>
>>>>
>>>>
>>>> with
>>>>
>>>> latv = (/22, 24.0, 24.0, 22.0, 22.0/)
>>>> lonv = (/76, 76.0, 78.0, 78.0, 76.0 /)
>>>>
>>>> then It's not giving mean of the square grid box.
>>>>
>>>> It shows the something like that (given below), which is incorrect. So
>>>> please let me know how can I get the square grid box mean and then extract
>>>> as asciiwrite or print?
>>>>
>>>> (0) 23.76603307545667 75.53995171540016
>>>> (0) 0.179
>>>> (1) 0.142
>>>> (2) -28672
>>>> (3) 0.169
>>>> (4) -28672
>>>> (5) -28672
>>>> (6) -28672
>>>> (0) -----
>>>> (0) 24.00322458681621 75.99551564353467
>>>> (0) 0.171
>>>> (1) 0.16
>>>> (2) -28672
>>>> (3) 0.17
>>>> (4) -28672
>>>> (5) -28672
>>>> (6) -28672
>>>>
>>>> etc..etc..
>>>>
>>>>
>>>>
>>>> regards
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>>
>>>>
>>>> Guido Cioni
>>>>
>>>> http://guidocioni.altervista.org
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> ************************************************************
>>>> **************
>>>> The information contained in the EMail and any attachments is
>>>> confidential and intended solely and for the attention and use of the named
>>>> addressee(s). It may not be disclosed to any other person without the
>>>> express authority of Public Health England, or the intended recipient, or
>>>> both. If you are not the intended recipient, you must not disclose, copy,
>>>> distribute or retain this message or any part of it. This footnote also
>>>> confirms that this EMail has been swept for computer viruses by
>>>> Symantec.Cloud, but please re-sweep any attachments before opening or
>>>> saving. http://www.gov.uk/PHE
>>>> ************************************************************
>>>> **************
>>>>
>>>
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> ncl-talk at ucar.edu
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>
>>>
>>
>>
>> --
>> Barry H. Lynn, Ph.D
>> Senior Lecturer,
>> The Institute of the Earth Science,
>> The Hebrew University of Jerusalem,
>> Givat Ram, Jerusalem 91904, Israel
>> Tel: 972 547 231 170
>> Fax: (972)-25662581
>>
>> C.E.O, Weather It Is, LTD
>> Weather and Climate Focus
>> http://weather-it-is.com
>> Jerusalem, Israel
>> Local: 02 930 9525
>> Cell: 054 7 231 170
>> Int-IS: x972 2 930 9525
>> US 914 432 3108 <091443%2023108>
>>
>
>
--
Barry H. Lynn, Ph.D
Senior Lecturer,
The Institute of the Earth Science,
The Hebrew University of Jerusalem,
Givat Ram, Jerusalem 91904, Israel
Tel: 972 547 231 170
Fax: (972)-25662581
C.E.O, Weather It Is, LTD
Weather and Climate Focus
http://weather-it-is.com
Jerusalem, Israel
Local: 02 930 9525
Cell: 054 7 231 170
Int-IS: x972 2 930 9525
US 914 432 3108
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20171025/8de56235/attachment.html>
More information about the ncl-talk
mailing list