Re: [netcdfgroup] Failure accessing an HYRAX OpenDAP server...

On Mon, Oct 17, 2016 at 11:15 AM, dmh@xxxxxxxx <dmh@xxxxxxxx> wrote:

> If you are using the netcdf-c library (thru python)
> then you may be able to get more info by prefixing the url
> So you might have
>     [log][show=fetch]http://...
>

nice hint! but I don't see anything useful. I've enclosed the log. Maybe
someone else can make some sense of it.






> =Dennis Heimbigner
>  Unidata
>
> On 10/17/2016 10:59 AM, Chris Barker wrote:
>
>>
>>
>> On Mon, Oct 17, 2016 at 6:38 AM, Kyle Wilcox <kyle@xxxxxxxxxxxxxxxxxxxx
>> <mailto:kyle@xxxxxxxxxxxxxxxxxxxx>> wrote:
>>
>>     I can confirm. Looks like a libdap/hyrax issue?
>>
>>
>> thanks -- does netcdf use libdap?
>>
>> but anyway, which one has the bug? One would need to see if the request
>> was being made correctly -- and I haqv no idea how to do that :-(
>>
>> -CHB
>>
>>
>>
>>
>>     DAS seems to work just fine while DODS is returning:
>>
>>     ...
>>     Error {
>>         code = -111;
>>         message = "libdap error transmitting DataDDS: Could not read the
>>     variable `ntimes'.";
>>     };
>>
>>     On Fri, Oct 14, 2016 at 5:43 PM Chris Barker <chris.barker@xxxxxxxx
>>     <mailto:chris.barker@xxxxxxxx>> wrote:
>>
>>         Hi all,
>>
>>         We're trying to use the netCDF4 python lib to access data on an
>>         what I thikn is a HYRAX server. It can create the Dataset object
>>         seemingly fine, and creates a variabel object fine -- but then
>>         gives me:
>>
>>         RuntimeError: NetCDF: file not found
>>
>>         when I try to extract some data from the variable.
>>
>>         Noett hat this seems to work fien with PyDAP -- so maybe that
>>         means that it's a netcdf lib problem, rather than a HYRAX problem.
>>
>>         But I have no idea how to debug this
>>
>>         I'm using a pretty recent version of the netcdf lib:
>>
>>         In [8]: netCDF4.getlibversion()
>>         Out[8]: u'4.4.1 of Aug 10 2016 18:32:53 $'
>>
>>         though the failure is the same with older versions as well. (and
>>         both on Windows and OS-X so far...)
>>
>>         I've enclosed a small python script that demonstrates the
>>         problem -- the problem url is in the script.
>>
>>         Thanks for any hints!
>>
>>         -CHB
>>
>>
>>
>>         --
>>
>>         Christopher Barker, Ph.D.
>>         Oceanographer
>>
>>         Emergency Response Division
>>         NOAA/NOS/OR&R            (206) 526-6959 <tel:(206)%20526-6959>
>>         voice
>>         7600 Sand Point Way NE   (206) 526-6329 <tel:(206)%20526-6329>
>>  fax
>>         Seattle, WA  98115       (206) 526-6317 <tel:(206)%20526-6317>
>>         main reception
>>
>>         Chris.Barker@xxxxxxxx <mailto:Chris.Barker@xxxxxxxx>
>>         _______________________________________________
>>         NOTE: All exchanges posted to Unidata maintained email lists are
>>         recorded in the Unidata inquiry tracking system and made publicly
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>>
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>> >
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>>
>>
>>
>>
>> --
>>
>> Christopher Barker, Ph.D.
>> Oceanographer
>>
>> Emergency Response Division
>> NOAA/NOS/OR&R            (206) 526-6959   voice
>> 7600 Sand Point Way NE   (206) 526-6329   fax
>> Seattle, WA  98115       (206) 526-6317   main reception
>>
>> Chris.Barker@xxxxxxxx <mailto:Chris.Barker@xxxxxxxx>
>>
>>
>> _______________________________________________
>> NOTE: All exchanges posted to Unidata maintained email lists are
>> recorded in the Unidata inquiry tracking system and made publicly
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>>
>>
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>>


-- 

Christopher Barker, Ph.D.
Oceanographer

Emergency Response Division
NOAA/NOS/OR&R            (206) 526-6959   voice
7600 Sand Point Way NE   (206) 526-6329   fax
Seattle, WA  98115       (206) 526-6317   main reception

Chris.Barker@xxxxxxxx

Attachment: hyrax_fail.log
Description: Binary data

# Example of  failed requet from a HYRAX server

from netCDF4 import Dataset
nc = 
Dataset('[log][show=fetch]http://ingria.coas.oregonstate.edu:80/opendap/aggregation/ocean_time_aggregation.ncml')

print("Dataset loaded OK")

u = nc.variables['u']

print("Successfully Extracted a varaible object:")
print(u)

u_shape = u.shape  # this works ok
print("The variable object is seemingly valid:")
print("the shape is %s" % (u_shape,))

print("but I can't extract the actual data")

u_data = u[0, 0, 0:10, 0:10:]  # this does not work--"RuntimeError: NetCDF: 
file not found"