astropy/asdf-astropy

Support `MagUnits`

WilliamJamieson opened this issue · 1 comments

WilliamJamieson commented

Support for MagUnit style units has been requested for the Roman Space Telescope output files. I think this is a reasonable request given we are working to resolve #144 (non-VOunits).

This should be relatively straight forward as we all MagUnit units essentially wrap a "physical unit" which we should be able to serialize already (for VOunits, and non-VOunits if #142 is merged). The heart of a schema for this would be:

type: object
properties:
  unit:
     oneOf:
       - tag: "tag:stsci.edu:asdf/unit/unit-1.0.0"
       - tag: "tag:astropy.org:astropy/units/unit-1.0.0"

Once the schema is setup it should be relatively straightforward to get the Converter integrated and working.

@mhvk or @nstarman as astropy.units maintainers do I need to do anything besides wrapping the physical unit inside the MagUnit?

mhvk commented

If you want to be complete, I'd also wrap the function_unit -- it principle it can be something like 2 mag (not that I hope that would ever happen). More helpfully, it means you can automatically also wrap DexUnit, DecibelUnit, and the more general LogUnit.

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