[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[netCDF #SAC-187452]: Question about netCDF library behavior across current and older versions.

Hello,

At the core, I would expect it is a bug in the 4.1.3 library; that it is fixed 
in later releases suggests that the issue was found and fixed at some point.  I 
was not aware of this specific issue, so thanks for bringing it to my 
attention!  Unfortunately, we won't have a fix for 4.1.3 but the newer versions 
of netCDF should work.  If you see this sort of behavior with a more recent 
version of netCDF (4.1.3 is over 6 years old at this point), please let us know!

-Ward

> Hi!
> I was trying to access old openDAP urls in older version of MATLAB that used 
> netCDF 4.1.3 and I get errors. Earlier our customers reported that accessing 
> these URLS causes MATLAB to sporadically crash in Windows.
> I expected to reproduce the same behavior but instead it errors out. But the 
> same URL works in newer MATLAB versions that are using netCDF 4.3.3 or 4.6.1.
> 
> For example in MATLAB R2014b (using netCDF 4.1.3)
> 
> >>ncepfile='http://www.esrl.noaa.gov/psd/thredds/dodsC/Datasets/ncep.reanalysis.dailyavgs/pressure/omega.1948.nc';
> >> ncdisp(ncepfile)
> 
> Error using netcdflib
> The NetCDF library encountered an error during execution of 'open' function - 
> 'I/O failure (NC_EIO)'. If the data source was an OPeNDAP URL, see the 
> OPeNDAP Troubleshooting section in the Users
> Guide.
> Error in netcdf.open (line 59)
> [varargout{:}] = netcdflib ( 'open', filename, varargin{1} );
> Error in internal.matlab.imagesci.nc/openToRead (line 1265)
> this.ncRootid = netcdf.open(this.Filename,'NOWRITE');
> Error in internal.matlab.imagesci.nc (line 121)
> this.openToRead();
> Error in ncdisp (line 50)
> ncObj = internal.matlab.imagesci.nc(ncFile);
> 
> 
> In MATLAB R2019a (using netCDF 4.6.1)
> 
> >>ncepfile='http://www.esrl.noaa.gov/psd/thredds/dodsC/Datasets/ncep.reanalysis.dailyavgs/pressure/omega.1948.nc';
> >> ncinfo(ncepfile)
> ans =
> struct with fields:
> 
> Filename: 
> 'http://www.esrl.noaa.gov/psd/thredds/dodsC/Datasets/ncep.reanalysis.dailyavgs/pressure/omega.1948.nc'
> Name: '/'
> Dimensions: [1×4 struct]
> Variables: [1×5 struct]
> Attributes: [1×8 struct]
> Groups: []
> Format: 'classic'
> 
> Please let me know if you are aware of this issue.
> 
> Thanks,
> Upanita
> 
> 


Ticket Details
===================
Ticket ID: SAC-187452
Department: Support netCDF
Priority: Normal
Status: Closed
===================
NOTE: All email exchanges with Unidata User Support are recorded in the Unidata 
inquiry tracking system and then made publicly available through the web.  If 
you do not want to have your interactions made available in this way, you must 
let us know in each email you send to us.