CDO 1.8.2 is changing attributes without notice
Added by Josué Bock almost 7 years ago
Hello,
When using usual commands which are not related to variable or dimension attributes, such as splitmon or ymonmean, I noticed that CDO changes (or adds, or deletes) several attributes, which is not really expected.
For instance, using ymonmean command on the attached file:
- an attribute "long_name" is added to the dimension plev (pressure level), but its value is set to "generic"
- the attributes "coordinates" are deleted for all variables (TACscat550aer_p, TACscat550so4_p, ...)
- the attribute "calendar" of the time_counter dimension is changed from "gregorian" to "standard"
- plus cosmetic changes, such as long_names changed from "Latitude" to "latitude"...
I am using cdo version 1.8.2.
The first change listed above was not occurring in my previous version (1.7.2) so it has been introduced recently.
I don't understand why CDO makes all these changes which are not requested, and without even warning the user that attributes have been changed. Focusing on the first change listed above (the "long_name" attribute added, with a value set to "generic"), I further wonder why the variable name is not used to fill this attribute field.
Cheers
Josué
Replies (2)
RE: CDO 1.8.2 is changing attributes without notice - Added by Uwe Schulzweida over 6 years ago
Hello Josué,
Thanks for your feedback and the example data!
CDO was developed to process GRIB and NetCDF data with the same interface. Therefor it is using an internal simple data model. The main focus was to handle the data correctly. The meta-data like the attributes and coordinates are handled totally different in GRIB and NetCDF. CDO needs to generalize and abstract some attributes. Some attributes are not handled correctly because the abstraction is missing (not implemented). In case of the coordinates attribute only the horizontal grid coordinates are supported, yet.
We constantly try to improve this situation.
The problems with the long_name attribute and the calendar are bugs, they will be fixed in the next CDO release!
Cheers,
Uwe
RE: CDO 1.8.2 is changing attributes without notice - Added by Josué Bock over 6 years ago
Hello Uwe,
Thank you for these explanations, and thanks also for the future developments and bugfix!
Cheers
Josué