How to read a NetCDF4 file in Matlab? I have downloaded the sea surface temperature data from the Ocean Color website, the file is in NetCDF format and contains no of geophysical_data variables like sst, qual_sst, flag_sst, bias_sst, etc.
I used the following MATLAB code for file read and it is giving me an error: 

temp=ncread('A2014213085500.L2_LAC_SST.x.nc','sst') 


Error:

Error using internal.matlab.imagesci.nc/getGroupAndVarid (line 2075)
Could not find variable or group 'sst' in file.

Error in internal.matlab.imagesci.nc/read (line 593)
        [gid, varid] = getGroupAndVarid(this, location);

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


Can someone tell me what is the cause of the error?
These days I use: ncgeodataset. The routine allows for the extraction of a subset of data without having to load the entire file or even an array into Matlab. It is great for large datasets.