[fitsbits] [mhvk at astro.utoronto.ca: Question about FITS format for logarithmic units]

[Marten van Kerkwijk]

Hi Tim, Arnold,

Tim: Agreed that logarithmic units are fairly awful, whether it is AB
magnitudes or dBm=dB(mW), but they are used, and I'd like, e.g., a
stellar atmosphere modeller not just to have a way to use logg (which
astropy will provide within python), but also to store results in
astronomy's de-facto standard, in a way that tells a user what a logg
column contains.

> Well, whether you like it or not, the log(unit) syntax is
> actually covered in the standard, in Section 4.3.1.

Arnold: Indeed it does, but it doesn't quite answer what to do with
log(dimensionless) or with PREFACTOR*log(unit) (i.e., mag, and dB)
... which of course is what triggered the questions in my e-mail.

Thanks!

Marten