Normally the assumption is that the roms netCDF unlimited record is <b>ocean_time</b>. If this is not the case, then specifying time_variable on the matlab command line can inform rslice of the name of the the proper unlimited record variable.

>> ncfile = '/p/jevans/dods-data/roms/nena/run4/his/2003_Oct_his.nc';
>> rslice ( 'file', ncfile, 'record_variable', 'ncep_time' );