Source code for astwro.starlist.StarList

import pandas as pd
import numpy as np
from astropy.table import Table
from astropy.coordinates import SkyCoord
import astropy.units as u
from .fileformats import DAO

# Subclassing pandas:

[docs]class StarList(pd.DataFrame): # # StarList properties extending pd.DataFrame _metadata = ['_DAO_hdr', '_DAO_type'] _DAO_hdr = None _DAO_type = None
[docs] @staticmethod def new(): """Returns empty StarList instance with columns id,x,y""" idx = pd.Series(name='id', dtype='int64') id = pd.Series(dtype='int64') x = pd.Series(dtype='float64') y = pd.Series(dtype='float64') return StarList({'id': id, 'x': x, 'y': y}, index=idx)
@property def _constructor(self): return StarList @property def DAO_hdr(self): """DAO file header dict if any""" return self._DAO_hdr @DAO_hdr.setter def DAO_hdr(self, hdr): self._DAO_hdr = hdr @property def DAO_type(self): """DAO file header dict if any""" return self._DAO_type @DAO_type.setter def DAO_type(self, typ): self._DAO_type = typ
[docs] def import_metadata(self, src): """Copies metdata (dao type, dao hdr) from src :param StarList src: source of metadata """ self.DAO_type = src.DAO_type self.DAO_hdr = src.DAO_hdr
[docs] def stars_number(self): """returns number of stars in list""" return self.shape[0]
[docs] def renumber(self, start=1): """Renumbers starlist (in place), updating `id` column and index to range start.. start+stars_number""" self['id'] = range(start, self.stars_number() + start) self.index =
[docs] def refresh_id(self): """Cheks for id column existence and renumber if needed then recreate index basin on id If `id` column exist but cannot be casted to `int` (by `pandas.Series.to_numeric`), `ValueError` exception is raised """ try: if self['id'].dtype != int: self['id'] = pd.to_numeric(self['id'], downcast='integer', errors='raise') except KeyError: self.renumber() self.index = self['id']
[docs] def to_table(self): """ Return a :class:`astropy.table.Table` instance """ t = Table.from_pandas(self) if self.DAO_hdr is not None: t.meta.update(self.DAO_hdr) if self.DAO_type is not None: t.meta['DAO_type'] = self.DAO_type return t
[docs] @classmethod def from_table(cls, table): """ Create a `StarList` from a :class:`astropy.table.Table` instance Parameters ---------- table : :class:`astropy.table.Table` The astropy :class:`astropy.table.Table` instance Returns ------- sl : `StarList` A `StarList`instance """ from .file_helpers import as_starlist return as_starlist(table)
[docs] @classmethod def from_skycoord(cls, coo): """ Create a `StarList` from a :class:`astropy.coordinates.SkyCoord` instance Parameters ---------- coo : :class:`astropy.coordinates.SkyCoord` Source Returns ------- sl : `StarList` A `StarList`instance """ sl = StarList( np.array([coo.ra.to_string(sep=':', unit=u.hourangle, pad=True), coo.dec.to_string(sep=':', unit=u.deg, pad=True, alwayssign=True)]).T, columns=['ra', 'dec']) sl.DAO_type = DAO.RADEC_FILE sl.renumber() return sl
def radec_hmsdms_from_skycoord(self, coo): self['ra'] = coo.ra.to_string(sep=':', unit=u.hourangle, pad=True) self['dec'] = coo.dec.to_string(sep=':', unit=u.deg, pad=True, alwayssign=True) def radec_deg_from_hmsdms(self): sky = SkyCoord(self.ra, self.dec, unit=(u.hourangle, u.deg)) self['ra_deg'] = sky.ra.deg self['dec_deg'] = sky.dec.deg def radec_hmsdms_from_deg(self): sky = SkyCoord(self.ra_deg, self.dec_deg, unit=u.deg) self['ra'] = sky.ra.to_string(sep=':', pad=True, unit=u.hourangle) self['dec'] = sky.dec.to_string(sep=':',pad=True, alwayssign=True) def to_skycoords(self): try: sky = SkyCoord(self.ra, self.dec, unit=(u.hourangle, u.deg)) except: sky = SkyCoord(self.ra_deg, self.dec_deg, unit=u.deg) return sky def xy_from_radec(self, fitsimage): from astwro.coord import skyradec2xy try: x,y = skyradec2xy(self.ra_deg, self.dec_deg, unit='deg', transformer=fitsimage) except: x,y = skyradec2xy(self.ra, self.dec, unit=(u.hourangle, u.deg), transformer=fitsimage) self['x'] = x self['y'] = y