Create an ANTS environment

[ScottWales]

Add an environment definition for creating ancils, which includes the ants and ug-ants packages

[hdyson]

As an ANTS/UG-ANTS developer, I'd encourage two discrete environments: one for ANTS and one for UG-ANTS.

We've made a deliberate design decision that ANTS and UG-ANTS can have different dependencies (for example, there's no mule requirement for UG-ANTS). So even if the environments are similar at present, they are likely to diverge in future without warning.

There is also an element here that ANTS is a mature package where we have stability requirements and need to be able to reproduce existing results. The results of ANTS with fixed dependencies are validated for particular model configurations (e.g. GC5, RAL4) with the relevant scientists. Given that a change in the underlying dependencies may change numeric results, we are cautious about changing ANTS dependencies (and this would also imply that an ANTS installation with the changed dependencies would not be equivalent for generating ancillaries for a standard configuration).

UG-ANTS is in a much more fluid state. This is reflected in the version numbers: ANTS is a stable release at 2.2, while UG-ANTS is at an unstable version of 0.3 (so as per SemVer, nothing in UG-ANTS should be considered to be fixed). We are more cautious with changes to the ANTS environment, but retain the option to be less risk averse for the UG-ANTS ones.

[ScottWales]

Thanks for the information. So ANTS and UG-ANTS are entirely separate then, a workflow using UG-ANTS doesn't use any of standard ANTS?

[arjclark]

Thanks for the information. So ANTS and UG-ANTS are entirely separate then, a workflow using UG-ANTS doesn't use any of standard ANTS?

An individual task/job in a workflow would be expected to be either an ANTS based one or a UG-ANTS based one, but both systems would be needed for an end to end ancil generation. For argument's sake it might look like:

ants_contrib_preprocesser => ants_ contrib_native_grid_data_processing => ug_ants_regridder => ug_ants_ug_contrib_ugrid_data_processing => ug_ants_netcdf_to_xios_saver

where:

• ants_contrib tasks are ANTS and associated contrib ones
• ug_ants_ug_contrib tasks are UG-ANTS and associated UG-contrib ones
• ug_ants_<cli_tool>are ug_ants standalone cli utility ones

Hope this helps?

[yaswant]

Scott Wales (@ScottWales) Also could I request you to remove the ants conda recipe from the repository and liaise with Andrew Clark (@arjclark) for guidance please?

[ScottWales]

Sure, no problem