Re: calipso datasets

I can not remember the details but you asked about an equivalent to the
IDL "find".
That is the "ind" function in NCL. The difference is thathe "find" can
work with
multidimensional arrays whereas the "ind" requires that the array be
one-dimensional.
Hence, you must use the 'ndtooned' function. [See also, "onedtond",
"ind_resolve"]

The "find" is more elegant but you can do much the same in NCL but with
more manual work.

As I recall, the HDF arrays were nominally 2D but were of sizes (1,N).
You wanted to locate
vales at particular locations. You could do

            j = ind(lat(0,:).eq.zlat)
            i = ind(lon(0,:).eq.zlon)

Lin Su wrote:
> Thanks Dennis:) The calipso team let me try WHERE function, but I'd like to use NCL. I just found there is WHERE function in NCL as well. Do you know anyone who works on CALIPSO data using NCL?
>
> Thank you,
> -Lin
> ---
> Lin Su
> http://atoc.colorado.edu/~sul/
>
> ---- Original message ----
>
>> Date: Thu, 17 Apr 2008 12:41:20 -0600
>> From: Dennis Shea <shea_at_ucar.edu>
>> Subject: Re: calipso datasets
>> To: Lin Su <Lin.Su_at_colorado.edu>
>> Cc: Mary Haley <haley_at_ucar.edu>
>>
>> Perhaps the "ind" function is what you want.
>>
>> http://www.ncl.ucar.edu/Document/Functions/Built-in/ind.shtml
>>
>> I do not know IDL so .....
>> D
>>
>> Lin Su wrote:
>>
>>> Hi Dennis,
>>>
>>> Thanks for your knidly reply:) The lat&lon in calipso is a function of time, so they give me the half orbit data although I just ordered the lat&lon pair around (39.98N, 116.36E). Do you think there is a function similar to WHERE(idl) to find the lat&lon pair that I need?
>>>
>>> Thanks a lot,
>>> -Lin
>>> ---
>>> Lin Su
>>> http://atoc.colorado.edu/~sul/
>>>
>>> ---- Original message ----
>>>
>>>
>>>> Date: Wed, 16 Apr 2008 10:18:24 -0600
>>>> From: Dennis Shea <shea_at_ucar.edu>
>>>> Subject: Re: calipso datasets
>>>> To: Lin Su <Lin.Su_at_Colorado.EDU>
>>>> Cc: ncl-talk_at_ucar.edu
>>>>
>>>> Lin Su wrote:
>>>>
>>>>
>>>>> Dear All,
>>>>>
>>>>> Does anyone have any experience to work on the calipso satellite data using NCL? I found the software NASA provided is for idl users.
>>>>>
>>>>>
>>>>>
>>>> Hiu Lin,
>>>>
>>>> It is a standard HDF file. You can always look at *any* supported
>>>> NCL file [nc, hdf, hdf-eos, grib-1, grib-2] by using ncl_filedump:
>>>>
>>>>
>>>> http://www.ncl.ucar.edu/Document/Tools/ncl_filedump.shtml
>>>>
>>>> %> ncl_filedump
>>>> CAL_LID_L2_40kmAProCal-Beta-V2-01.2007-04-03T05-00-44ZD.hdf | less
>>>>
>>>> filename: CAL_LID_L2_40kmAProCal-Beta-V2-01.2007-04-03T05-00-44ZD
>>>> path: CAL_LID_L2_40kmAProCal-Beta-V2-01.2007-04-03T05-00-44ZD.hdf
>>>> file global attributes:
>>>> coremetadata :
>>>> GROUP = INVENTORYMETADATA
>>>> GROUPTYPE = MASTERGROUP
>>>> GROUP = GRANULE
>>>> OBJECT = GRANULEID
>>>> NUM_VAL = 1
>>>> VALUE = "L2_LIDAR"
>>>> END_OBJECT = GRANULEID
>>>> [SNIP ---------------------------------------------------------]
>>>>
>>>> There are a number of "fakeDim*" Why? the HDF creators did not
>>>> name the dimensions!! Always explore the data .... this is how to
>>>> learn about it.
>>>> IMHO .... much simpler than IDL.
>>>>
>>>> ncl 0> f = addfile
>>>> ("CAL_LID_L2_40kmAProCal-Beta-V2-01.2007-04-03T05-00-44ZD.hdf" , "r")
>>>> ncl 1> print(f)
>>>> ncl 2> lstrt = f->Latitude_Start
>>>> ncl 3> print(lstrt)
>>>> Variable: lstrt
>>>> Type: float
>>>> Total Size: 4 bytes
>>>> 1 values
>>>> Number of Dimensions: 2
>>>> Dimensions and sizes: [fakeDim0 | 1] x [fakeDim1 | 1]
>>>> Coordinates:
>>>> Number Of Attributes: 4
>>>> units : deg
>>>> format : Float_32
>>>> valid_range : -90.0...90.0
>>>> hdf_name : Latitude_Start
>>>> (0,0) -80.90755
>>>> FYI: The
>>>> "Latitude_Stop" is -80.7469
>>>> The
>>>> "Longitude_Start" is -165.3068
>>>> The
>>>> "Longitude_Stop" is -167.3159
>>>> --------------------------------
>>>> ncl 4 > T = f->Temperature
>>>> ncl 5 > print(T)
>>>>
>>>> Variable: T
>>>> Type: float
>>>> Total Size: 796 bytes
>>>> 199 values
>>>> Number of Dimensions: 2
>>>> Dimensions and sizes: [fakeDim20 | 1] x [fakeDim21 | 199]
>>>> Coordinates:
>>>> Number Of Attributes: 4
>>>> units : degrees C
>>>> format : Float_32
>>>> valid_range : TBD
>>>> hdf_name : Temperature
>>>> (0,0) -62.10014
>>>> (0,1) -62.15202
>>>> (0,2) -62.20389
>>>> (0,3) -62.25577
>>>> [SNIP--------------------------------]
>>>>
>>>>
>> --
>> ======================================================
>> Dennis J. Shea tel: 303-497-1361 |
>> P.O. Box 3000 fax: 303-497-1333 |
>> Climate Analysis Section |
>> Climate & Global Dynamics Div. |
>> National Center for Atmospheric Research |
>> Boulder, CO 80307 |
>> USA email: shea 'at' ucar.edu |
>> ======================================================
>>
>>

-- 
======================================================
Dennis J. Shea                  tel: 303-497-1361    |
P.O. Box 3000                   fax: 303-497-1333    |
Climate Analysis Section                             |
Climate & Global Dynamics Div.                       |
National Center for Atmospheric Research             |
Boulder, CO  80307                                   |
USA                        email: shea 'at' ucar.edu |
======================================================
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