[ncl-talk] set_dimension_query
Kunal Bali
kunal.bali9 at gmail.com
Wed Sep 13 12:35:38 MDT 2017
For direct output as a netcdf format, I used the script given below. It
produced the netcdf file easily. But the netcdf file and original hdf file
both showing the different results. The data pattern is shifted. I mean it
may be related to the lat lon position. please see the attached file, you
will understand. And please let me know which one is correct.
;----------------------------------------------------------------------
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
begin
;---Read data
a = addfile("/media/Local
Disk/NPL/MODIS_FPC/MAIACTAOT.h00v02.20000570505.hdf","r")
var = short2flt(a->Optical_Depth_055(:,:))
; short2flt(a[:]->noxfire)
nlat = 1200
nlon = 1200
lat = latGlobeFo(nlat, "lat", "latitude", "degrees_north")
lon = lonGlobeFo(nlon, "lon", "longitude", "degrees_east")
lat = lat(::-1)
lon = (/ lon - 180. /) ; subtract 180 from all values
lon&lon = lon ; update coordinates
var!0 = "lat" ; you can name these dimensions whatever you want..
var!1 = "lon"
var&lat = lat ; but make sure you refer to the correct named
dimensions
var&lon = lon
system("/bin/rm -f simple.nc")
ncdf = addfile("simple.nc" ,"c") ; open output netCDF file
;===================================================================
; create global attributes of the file (optional)
;===================================================================
fAtt = True ; assign file attributes
fAtt at title = "NCL Simple Approach to netCDF Creation"
fAtt at source_file = "original-file.nc"
fAtt at Conventions = "None"
fAtt at creation_date = systemfunc ("date")
fileattdef( ncdf, fAtt ) ; copy file attributes
;===================================================================
; make time an UNLIMITED dimension; recommended for most applications
;===================================================================
filedimdef(ncdf,"time",-1,True)
ncdf->var = var
end
Kunal Bali
On Wed, Sep 13, 2017 at 11:27 PM, Kunal Bali <kunal.bali9 at gmail.com> wrote:
> No problem, I sorted out.
>
> Just changed short to float.
>
> Kunal Bali
> Research Scholar
> Radio & Atmospheric Science Division
> CSIR - National Physical Laboratory
> New Delhi - 110012
> India
>
>
>
>
>
> On Wed, Sep 13, 2017 at 11:24 PM, Kunal Bali <kunal.bali9 at gmail.com>
> wrote:
>
>> Thanks for providing this information.
>>
>> Also, I would like to mention that when I plot this data. The values are
>> not in the domain. I mean the real values lie in-between 0 to 1 but here it
>> is reaching to 400.
>>
>> So, how to correct the values?
>>
>> Description of the variable is
>>
>> short Optical_Depth_055(YDim=1200, XDim=1200);
>> :long_name = "AOT at 0.55 micron";
>> :scale_factor = 0.001; // double
>> :add_offset = 0.0; // double
>> :unit = "None";
>> :_FillValue = -28672S; // short
>> :valid_range = -100S, 5000S; // short
>>
>>
>>
>>
>> Kunal Bali
>>
>>
>>
>>
>>
>>
>> On Wed, Sep 13, 2017 at 10:28 PM, Adam Phillips <asphilli at ucar.edu>
>> wrote:
>>
>>> Hi Kunal,
>>> Yes, clicking on the output netCDF link from the Applications page:
>>> http://www.ncl.ucar.edu/Applications/o-netcdf.shtml
>>> I would recommend following the inefficient method #1. Unless you are
>>> writing a file with many large variables, the inefficient method works just
>>> fine.
>>> http://www.ncl.ucar.edu/Applications/method_1.shtml
>>> Good luck,
>>> Adam
>>>
>>> On Wed, Sep 13, 2017 at 10:25 AM, Kunal Bali <kunal.bali9 at gmail.com>
>>> wrote:
>>>
>>>> Thank you so much, it worked
>>>>
>>>> I want to know one more thing.
>>>> After rearranging the dimensions can we now convert (or write) this
>>>> arranged file into netcdf format?
>>>>
>>>>
>>>>
>>>> Kunal Bali
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Sep 13, 2017 at 8:55 PM, Adam Phillips <asphilli at ucar.edu>
>>>> wrote:
>>>>
>>>>> Hi Kunal,
>>>>> I think you just need to rearrange the order of your lines and tweak a
>>>>> couple of lines. As the error message states, lat is not defined in your
>>>>> 3rd line and you are referring to it as if it is.Try this:
>>>>> a = addfile("/media/Local Disk/NPL/MODIS_FPC/MAIACTAOT.h
>>>>> 00v02.20000570505.hdf","r")
>>>>> var = a->Optical_Depth_055(:,:)
>>>>> nlat = 1200
>>>>> nlon = 1200
>>>>> lat = latGlobeFo(nlat, "lat", "latitude", "degrees_north")
>>>>> lon = lonGlobeFo(nlon, "lon", "longitude", "degrees_east")
>>>>> lat = lat(::-1)
>>>>> lon = (/ lon - 180. /) ; subtract 180 from all values
>>>>> lon&lon = lon ; update coordinates
>>>>>
>>>>> var!0 = "lat" ; you can name these dimensions whatever you want..
>>>>> var!1 = "lon"
>>>>> var&lat = lat ; but make sure you refer to the correct named
>>>>> dimensions
>>>>> var&lat = lon
>>>>> ;var&XDim_grid1km = lat
>>>>> ;var&YDim_grid1km = lon
>>>>>
>>>>> If you have any further questions please respond to the ncl-talk email
>>>>> list.
>>>>> Adam
>>>>>
>>>>>
>>>>>
>>>>> On Wed, Sep 13, 2017 at 8:38 AM, Kunal Bali <kunal.bali9 at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Dear NCL
>>>>>>
>>>>>> I have a file with the variable summary. The dimensions are in 2D.
>>>>>>
>>>>>> ncl 2> printVarSummary(var)
>>>>>>
>>>>>> Variable: var
>>>>>> Type: short
>>>>>> Total Size: 2880000 bytes
>>>>>> 1440000 values
>>>>>> Number of Dimensions: 2
>>>>>> Dimensions and sizes: [*YDim_grid1km | 1200] x [XDim_grid1km |
>>>>>> 1200]*
>>>>>> Coordinates:
>>>>>> Number Of Attributes: 7
>>>>>> long_name : AOT at 0.55 micron
>>>>>> scale_factor : 0.001
>>>>>> add_offset : 0
>>>>>> unit : None
>>>>>> _FillValue : -28672
>>>>>> valid_range : ( -100, 5000 )
>>>>>> hdf_name : Optical_Depth_055
>>>>>>
>>>>>>
>>>>>> I am trying to read the dimensions of this file as
>>>>>>
>>>>>> begin
>>>>>> ;---Read data
>>>>>> a = addfile("/media/Local Disk/NPL/MODIS_FPC/MAIACTAOT.h
>>>>>> 00v02.20000570505.hdf","r")
>>>>>>
>>>>>> var = a->Optical_Depth_055(:,:)
>>>>>>
>>>>>> var&XDim_grid1km = lat
>>>>>> var&YDim_grid1km = lon
>>>>>>
>>>>>> nlat = 1200
>>>>>> nlon = 1200
>>>>>> lat = latGlobeFo(nlat, "lat", "latitude", "degrees_north")
>>>>>> lon = lonGlobeFo(nlon, "lon", "longitude", "degrees_east")
>>>>>> lat = lat(::-1)
>>>>>> lon = (/ lon - 180. /) ; subtract 180 from all values
>>>>>> lon&lon = lon ; update coordinates
>>>>>>
>>>>>>
>>>>>> var!0 = "lat"
>>>>>> var!1 = "lon"
>>>>>>
>>>>>>
>>>>>> But the error appeared as
>>>>>> *fatal:Variable (lat) is undefined*
>>>>>>
>>>>>>
>>>>>> So, could anyone please let me know that how to read dimension of
>>>>>> this file.
>>>>>>
>>>>>> Thank You
>>>>>>
>>>>>>
>>>>>> 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
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Adam Phillips
>>>>> Associate Scientist, Climate and Global Dynamics Laboratory, NCAR
>>>>> www.cgd.ucar.edu/staff/asphilli/ 303-497-1726 <(303)%20497-1726>
>>>>>
>>>>> <http://www.cgd.ucar.edu/staff/asphilli>
>>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>
>>>
>>> --
>>> Adam Phillips
>>> Associate Scientist, Climate and Global Dynamics Laboratory, NCAR
>>> www.cgd.ucar.edu/staff/asphilli/ 303-497-1726
>>>
>>> <http://www.cgd.ucar.edu/staff/asphilli>
>>>
>>
>>
>
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