R1i PdZddlZddlmZddlmZddlmZddlm Z m Z dZ d Z y) aCConstellation identification. Constellation identification is tradionally performed with: http://cdsarc.u-strasbg.fr/viz-bin/Cat?VI/42 https://iopscience.iop.org/article/10.1086/132034/pdf Given a position, a binary search can be used to index into its roughly 12k data table for a matching declination, but the table then needs to be scanned linearly for the first subsequent segment that contains the target right ascension within its bounds. The big problem for Skyfield: that algorithm can't be constructed from vectorized NumPy primitives. So we here take an approach that requires no linear search. The sky is divided into a grid, with a grid line at every right ascension and declination that is mentioned in a constellation boundary. This is a bit wasteful, as many values are only ever used for one boundary, but makes the search easy: do a binary search for right ascension, then for declination, then look up the indexes in the grid. Memory requirement: 1.8k right ascension table 1.6k declination table 46.6k grid table 1k constellation name abbreviations N) searchsorted)get_data)load_bundled_npy)Timejulian_date_of_besselian_epochctdtdtd}|d|d|d|dfd}|S) aLLoad Skyfield's constellation boundaries and return a lookup function. Skyfield carries an internal map of constellation boundaries that is optimized for quick position lookup. Call this function to load the map and return a function mapping position to constellation name. >>> from skyfield.api import position_of_radec, load_constellation_map >>> constellation_at = load_constellation_map() >>> north_pole = position_of_radec(0, 90) >>> constellation_at(north_pole) 'UMi' If you pass an array of positions, you'll receive an array of names. NiSzconstellations.npz sorted_ra sorted_decradec_to_indexindexed_abbreviationsc|j \}}}t |j}t |jd}||f}|S)N)epochright)side)radecrhoursdegrees) positionradecdistanceijkr r r r t1875s ]/home/cursorai/projects/iching/venv/lib/python3.12/site-packages/skyfield/constellationlib.pyconstellation_atz0load_constellation_map..constellation_at:sU$NNN7C BHH - S[[w ? 1a4 $Q'')rrr)arraysrr r r r rs @@@@@rload_constellation_mapr!"s_ 5d; >> from skyfield.api import load_constellation_names >>> d = dict(load_constellation_names()) >>> d['UMa'] 'Ursa Major' By swapping the order of the two items, you can map the other way, from a full name back to an abbreviation: >>> f = dict(reversed(item) for item in load_constellation_names()) >>> f['Ursa Major'] 'UMa' skyfieldzdata/constellations.gz )wbitsascii r)rzlib decompress MAX_WBITSdecode splitlinessplit)datalines rload_constellation_namesr0Csa& J 8 9D ??4t~~b'8 9 @ @ ID+/??+< =+<4DJJsA +< == =sA2) __doc__r(numpyrpkgutilr functionsrtimelibrrr!r0rrr7s&4 '9B>r