Documentation for color laws

[cgarling]

Currently the documentation for some of the color laws (e.g., F99, Cal00, CCM89) says that they return E(B-V).
If I'm not mistaken, these actually give the ratio A_lambda / A_V, where A_lambda is the extinction in magnitudes at the input wavelength and A_V is the extinction in V band. A_V can be computed as R_v * E(B-V), where E(B-V) can be looked up via SFD98Map for Galactic extinction. Could you correct these docstrings?

[icweaver]

Yea, I feel like I'm missing something super obvious, but am all for this if nobody else has any objections?

[cgarling]

Appendix B of Fitzpatrick+2019 gives the conversion between these definitions and we are doing some of these conversions in our tests for this model (see here). This is another example where the docstring for F19 sounds to me like it is claiming to return E(x-V)/E(B-V) when the tests indicate it is returning A(x)/A(V).

[icweaver]

Good digging! Ah, the plot thickens. According to git blame, that was Ian from the past that added that conversion in the tests 😅

[cgarling]

My hunch is that the tests are correct and docstrings are incorrect

For example there is also reference to A(x) / A_V in code comments (e.g. here)

[icweaver]

Mkay, went through the original papers for each law and updated accordingly in the docs (#67). Also fixed a plotting issue for CAL00. It's just a kludge until the Makie PR is merged though