Focus

[julienguy]

This PR adds to the Hartmann doors analysis the possibility to fit for the spectrograph cryostat focus tip tilt in addition to the piston. This has still to be validated with a real adjustment.

[julienguy]

Code validated with SM2-b8 refocus sequence on 2023/06/07 (NIGHT=20230606).

Before:

INFO:desi_hartmann_analysis:106:<module>: LEFT = psf-b8-179633-left.fits RIGHT= psf-b8-179634-right.fits dy = -0.020 +- 0.148 pixels
INFO:desi_hartmann_analysis:137:<module>: SM2-b8 LEFT-RIGHT(closed) DELTA = -0.023 +- 0.0082 pix (N=510)
INFO:desi_hartmann_analysis:138:<module>: SM2-b8 DEFOCUS = +0.001 +- 0.0004 mm (N=510) (the correction to apply is of opposite sign)
INFO:desi_hartmann_analysis:155:<module>: best focus gauges offsets to add (TOP,LEFT,RIGHT) = 0.011 0.023 -0.050 mm

After adjusting the cryostat position:

INFO:desi_hartmann_analysis:106:<module>: LEFT = psf-b8-184142-left.fits RIGHT= psf-b8-184143-right.fits dy = 0.036 +- 0.103 pixels
INFO:desi_hartmann_analysis:137:<module>: SM2-b8 LEFT-RIGHT(closed) DELTA = +0.058 +- 0.0057 pix (N=510)
INFO:desi_hartmann_analysis:138:<module>: SM2-b8 DEFOCUS = -0.003 +- 0.0003 mm (N=510) (the correction to apply is of opposite sign)
INFO:desi_hartmann_analysis:155:<module>: best focus gauges offsets to add (TOP,LEFT,RIGHT) = 0.007 -0.002 -0.001 mm

[julienguy]

I don't understand the error on the test 'API doc completeness test' .
https://github.com/desihub/desispec/actions/runs/4961299915/jobs/8877917833?pr=2042

[sbailey]

I don't understand the error on the test 'API doc completeness test' .
https://github.com/desihub/desispec/actions/runs/4961299915/jobs/8877917833?pr=2042

When you add a new module (like focus.py), you also need to add it to doc/api.rst so that it will be included in the documentation. Historically we didn't have that test and the docs would get way out of date with the actual code, but now the tests catch it whenever a new module is added.

Detail: I think you need to add two more = to the underbar of this title to keep sphinx / rst happy:

desispec.focus
============

[sbailey]

The code itself looks fine and the "testing with actual use" is better than any review I could do, so ok to merge once the doctest thing is sorted out.