Error using matlab.int​ernal.imag​esci.netcd​flib , R2021b

I get an error using ncread

The script works on earlier release (R2020a)

What could be the reason for this?

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Error using matlab.internal.imagesci.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 67)

[varargout{:}] = matlab.internal.imagesci.netcdflib ( 'open', filename, varargin{1} );

Error in internal.matlab.imagesci.nc/openToRead (line 1280)

this.ncRootid = netcdf.open(this.Filename,'NOWRITE');

Error in internal.matlab.imagesci.nc (line 124)

this.openToRead();

Error in ncread (line 61)

ncObj = internal.matlab.imagesci.nc(ncFile);

Error in file (line 56)

lon = ncread(urlget,'longitude');

>>

Answer 1

[Abhijeet]

Hi Simon ,

I understand that you are facing isssue while using "ncread" function in MATLAB R2021b.

This is a known issue with the recent versions of the NetCDF library that is used by "ncread" function to query the OPeNDAP data. There has been a change in the implementation of this third-party library which is causing unintended errors in MATLAB and other programming languages that use this library.

To resolve this issue please refer either of the following workaround :-

1. Prepend the "ncread" source URL with “[fillmismatch]”

time=ncread("[fillmismatch]http://sccoos.org/thredds/dodsC/autoss/scripps_pier-2019.nc","time""); 

2. Append the "ncread" source URL with “#fillmismatch”

time=ncread("http://sccoos.org/thredds/dodsC/autoss/scripps_pier-2019.nc#fillmismatch","time""); 

I hope this resolves the issue you were facing.