CF convention says this:
The CF convention places no rigid restrictions on the order of dimensions, however we encourage data producers to make the extra effort to stay within the COARDS standard order.
Then it says this:
The use of non-COARDS axis ordering will render files inaccessible to some applications and limit interoperability.
I learned this the hard way, when I tried to use CDO tools on my data and found it would not operate on the data without a re-ordering of the dimensions.
At the time I used cf-checker to confirm compliance with CF conventions, this would have been a trivial fix. Now it is very, very, non-trivial. ECMWF maintains a grib2nc converter for their data which apparently got caught in the same trap (they are in the midst of a major update to change the dimension order).
So, for the benefit of all future users, I would like to request the addition of a feature to check dimension order against COARDS, in order to ensure that CDO and other tools interoperate correctly.
CF convention says this:
Then it says this:
I learned this the hard way, when I tried to use CDO tools on my data and found it would not operate on the data without a re-ordering of the dimensions.
At the time I used cf-checker to confirm compliance with CF conventions, this would have been a trivial fix. Now it is very, very, non-trivial. ECMWF maintains a grib2nc converter for their data which apparently got caught in the same trap (they are in the midst of a major update to change the dimension order).
So, for the benefit of all future users, I would like to request the addition of a feature to check dimension order against COARDS, in order to ensure that CDO and other tools interoperate correctly.