[thredds] NetCDF Access failure with matlab and python

• To: thredds@xxxxxxxxxxxxxxxx
• Subject: [thredds] NetCDF Access failure with matlab and python
• From: Thomas Cook <tmcook@xxxxxxxx>
• Date: Wed, 16 Jan 2019 16:51:15 -0800

HI
I just yesterday updated my thredds-docker to 4.6.12 from
4.6.12-snapshot. It seems to be running fine, except I'm getting
errors using matlab ncread and python netcdf4.dataset. When I try to
access any of the multi-dimensional (time, lat, lon) variables I get
the following errors
with matlab:
Error using netcdflib
The NetCDF library encountered an error during execution of
'getVarsShort' function - 'Access failure (-77)'.

Error in netcdf.getVar (line 136)
    data = netcdflib(funcstr,ncid,varid,varargin{:});

Error in internal.matlab.imagesci.nc/read (line 635)
                data  = netcdf.getVar(gid, varid, ...

Error in ncread (line 58)
vardata = ncObj.read(varName, varargin{:});

Error in readUVfromTDS (line 56)
u=ncread(url, 'u_mean', [1 1 1], [2 2 2]);


and with python:
netCDF4/_netCDF4.pyx in netCDF4._netCDF4.Variable.__getitem__()

netCDF4/_netCDF4.pyx in netCDF4._netCDF4.Variable._get()

netCDF4/_netCDF4.pyx in netCDF4._netCDF4._ensure_nc_success()

RuntimeError: NetCDF: Access failure

I know that the latest docker contains netcdf 4.6, where as the
snapshot had 4.4. Could it be a version problem with the netCD4 python
and matlab libraries? I should be running the latest netcdf python
version and not too far behind with matlab versions.

The weird things are that the index variables are accessible (time,
lat, lon etc),  and the multiple-dimension data is accessible just
fine using the OpenDap web interface and Panoply. So I'm a little
confused. I'm addressing this list since I think there might be some
matlab and python expertise here and I think there were some messages
about the Access failure error in the past.

Thanks,
Tom

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  • Re: [thredds] NetCDF Access failure with matlab and python
    • From: Thomas Cook