[ncl-talk] binary file read

[Dennis Shea]

I speculate that IDL's 'read_binary' reads files created by IDL's
'write_binary'.

I think this is a special IDL data structure.



On Wed, Mar 29, 2017 at 5:03 PM, Debasish Hazra <debasish.hazra5 at gmail.com>
wrote:

> Thanks Mary for looking in to it. I have find only one IDL file that read
> that data set and it is attahced.
>
> Debasish.
>
> On Wed, Mar 29, 2017 at 5:28 PM, Mary Haley <haley at ucar.edu> wrote:
>
>> Hi Debasish,
>>
>> Kevin and I took a look at this. For starters, there *is* an error
>> message coming out of your script:
>>
>> warning:cbinread: The size implied by the dimension arrays is greater
>> that the size of the file.
>>  The default _FillValue for the specified type will be filled in.
>>  Note dimensions and values may not be aligned properly
>>
>> If you look at the size of the file, it doesn't match with the dimensions
>> you're requesting:
>>
>> Size of file = 8294400 bytes
>>
>> Size of dimensions = 5 * 720 * 1440 * 4 (for a uint) = 20736000
>>
>> If this is truly a C binary file, it looks like it only has 2 * 720 *
>> 1440 * 4 bytes.
>>
>> This doesn't really change the results, however, because you still get
>> two strange looking plots.
>>
>> We tried several different things:
>>
>> 1) reading the data as ubyte, int, and ushort
>> 2) reversing the array to 1440 x 720 x 2
>> 3) reading the data as little endian
>> 4) plotting the data as a simple contour plot to take out the map
>> component.
>>
>> Nothing we did produced more information about the file, or produced
>> better plots.
>>
>> Is there some documentation on this file to understand how it was
>> written? For example, are you sure the "uint" type is correct? Are you sure
>> the dimension sizes are correct? Why are the values so large? Is it
>> possible that this is "packed" data, and that you need to use a function
>> like dim_gbits to pick off individual bits of information?
>>
>> If you can find a C or Fortran code that was used to create this file,
>> then it should be fairly straightforward to figure out how to read it.
>>
>> --Mary
>>
>>
>>
>>
>>
>>
>> On Wed, Mar 29, 2017 at 2:18 PM, Debasish Hazra <
>> debasish.hazra5 at gmail.com> wrote:
>>
>>> Hi,
>>>
>>> I am trying to read a binary file with the attached code, but  getting
>>> all empty fields in the figure with no apparent error message. Uploaded
>>>  the data file in the ftp server "viirs_meandbdi_gridded_statis2015048.dat".
>>> Any help with this is appreciated.
>>>
>>> Thanks.
>>> Debasish
>>>
>>> On Wed, Mar 22, 2017 at 10:33 AM, Debasish Hazra <
>>> debasish.hazra5 at gmail.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> I am trying to read a binary file with the attached code, but  getting
>>>> all empty fields in the figure with no apparent error message. Uploaded
>>>>  the data file in the ftp server "viirs_meandbdi_gridded_statis2015002.dat".
>>>> Any help with this is appreciated.
>>>>
>>>> Thanks.
>>>> Debasish.
>>>>
>>>>
>>>>
>>>
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>>
>
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