Re: [netcdfgroup] Netcdf checker problem

Hi Philippe,

The reason the checker has flagged an error is because the contents of the attribute flag_values should be of type "string" (see attributes appendix in CF conventions doc. If you put "" around the value i.e. flag_values = "0b, 1b"; then the error will go away.

I notice that the example in the CF Conventions document doesn't use quotes
either, so I will raise this with the CF bods to determine if I need to make a change
to the checker or if the example is incorrect.


[netcdfgroup] Netcdf checker problem
Philippe Poilbarbe <Philippe.Poilbarbe@xxxxxx>
Mon, 01 Oct 2007 17:52:29 +0200

Netcdf group <netcdfgroup@xxxxxxxxxxxxxxxx>


For a new satellite launch, we have decided to use NetCDF files to
deliver product data.
They will be CF-1.0 compliant and we are checking our definitions with
the online checker (

For a variable (in fact for all variables which have the flag_values
attribute) we
have the error message:

ERROR: Attribute flag_values of incorrect type

The variable definition is:

byte alt_echo_type(time) ;
       alt_echo_type:long_name = "altimeter echo type" ;
       alt_echo_type:_FillValue = 127b ;
       alt_echo_type:flag_values = 0b, 1b ;
       alt_echo_type:flag_meanings = "ocean_like non_ocean_like" ;
       alt_echo_type:coordinates = "lon lat" ;

As recommended in the CF-1.0 documentation, the type of the
flag_values attribute is the same as the variable one.

So here is my question: what is wrong ? In my definition or
in the checker ?


-- Philippe Poilbarbe CLS - Space Oceanography Division

Rosalyn Hatcher
NCAS Computational Modelling Support
Dept. of Meteorology, University of Reading, Earley Gate, Reading. RG6 6BB
Email: r.s.hatcher@xxxxxxxxxxxxx     Tel: +44 (0) 118 378 6016