def transform_celestial(coords, systems):
lons, lats = np.radians(coords['lon']), np.radians(coords['lat'])
out = Table()
out['lon'] = np.zeros(len(coords), dtype='float64')
out['lat'] = np.zeros(len(coords), dtype='float64')
for ii, (lon, lat) in enumerate(zip(lons, lats)):
# First convert to FK5 J2000 in all cases
if systems['in'] == 'fk4':
lon, lat = slalib.sla_fk45z(lon, lat, 2000.0012775136652)
elif systems['in'] == 'icrs':
lon, lat = slalib.sla_hfk5z(lon, lat, 2000)[:2]
elif systems['in'] == 'galactic':
lon, lat = slalib.sla_galeq(lon, lat)
elif systems['in'] == 'ecliptic':
lon, lat = slalib.sla_ecleq(lon, lat, 51544)
# Now convert from FK5 J2000 to out system
if systems['out'] == 'fk4':
# FK5 -> FK4 at BEPOCH 2000 assuming no proper motion or parallax
lon, lat = slalib.sla_fk54z(lon, lat, 2000.0012775136652)[:2]
elif systems['out'] == 'icrs':
# FK5 -> Hipparcos (i.e. ICRF, which is as close as SLALIB
# gets to ICRS) at epoch 2000 and with no proper motion
lon, lat = slalib.sla_fk5hz(lon, lat, 2000)
elif systems['out'] == 'galactic':
# FK5 -> Galactic
lon, lat = slalib.sla_eqgal(lon, lat)
elif systems['out'] == 'ecliptic':
# FK5 -> Ecliptic at TDB (MJD) 51544 (i.e. J2000)
lon, lat = slalib.sla_eqecl(lon, lat, 51544)
out[ii]['lon'] = np.degrees(lon)
out[ii]['lat'] = np.degrees(lat)
return out
def transform_celestial(coords, systems):
lons, lats = np.radians(coords['lon']), np.radians(coords['lat'])
out = Table()
out['lon'] = np.zeros(len(coords), dtype='float64')
out['lat'] = np.zeros(len(coords), dtype='float64')
for ii, (lon, lat) in enumerate(zip(lons, lats)):
# First convert to FK5 J2000 in all cases
if systems['in'] == 'fk4':
lon, lat = slalib.sla_fk45z(lon, lat, 2000.0012775136652)
elif systems['in'] == 'icrs':
lon, lat = slalib.sla_hfk5z(lon, lat, 2000)[:2]
elif systems['in'] == 'galactic':
lon, lat = slalib.sla_galeq(lon, lat)
elif systems['in'] == 'ecliptic':
lon, lat = slalib.sla_ecleq(lon, lat, 51544)
# Now convert from FK5 J2000 to out system
if systems['out'] == 'fk4':
# FK5 -> FK4 at BEPOCH 2000 assuming no proper motion or parallax
lon, lat = slalib.sla_fk54z(lon, lat, 2000.0012775136652)[:2]
elif systems['out'] == 'icrs':
# FK5 -> Hipparcos (i.e. ICRF, which is as close as SLALIB
# gets to ICRS) at epoch 2000 and with no proper motion
lon, lat = slalib.sla_fk5hz(lon, lat, 2000)
elif systems['out'] == 'galactic':
# FK5 -> Galactic
lon, lat = slalib.sla_eqgal(lon, lat)
elif systems['out'] == 'ecliptic':
# FK5 -> Ecliptic at TDB (MJD) 51544 (i.e. J2000)
lon, lat = slalib.sla_eqecl(lon, lat, 51544)
out[ii]['lon'] = np.degrees(lon)
out[ii]['lat'] = np.degrees(lat)
return out
def convert(coords, systems):
if not set(systems.values()).issubset(SUPPORTED_SYSTEMS):
return None
lons, lats = np.radians(coords['lon']), np.radians(coords['lat'])
for ii, (lon, lat) in enumerate(zip(lons, lats)):
# First convert to FK5 J2000 in all cases
if systems['in'] == 'fk4':
lon, lat = slalib.sla_fk45z(lon, lat, 2000.0012775136652)
elif systems['in'] == 'icrs':
lon, lat = slalib.sla_hfk5z(lon, lat, 2000)[:2]
elif systems['in'] == 'galactic':
lon, lat = slalib.sla_galeq(lon, lat)
elif systems['in'] == 'ecliptic':
lon, lat = slalib.sla_ecleq(lon, lat, 51544)
# Now convert from FK5 J2000 to out system
if systems['out'] == 'fk4':
# FK5 -> FK4 at BEPOCH 2000 assuming no proper motion or parallax
lon, lat = slalib.sla_fk54z (lon, lat, 2000.0012775136652)[:2]
elif systems['out'] == 'icrs':
# FK5 -> Hipparcos (i.e. ICRF, which is as close as SLALIB
# gets to ICRS) at epoch 2000 and with no proper motion
lon, lat = slalib.sla_fk5hz(lon, lat, 2000)
elif systems['out'] == 'galactic':
# FK5 -> Galactic
lon, lat = slalib.sla_eqgal(lon, lat)
elif systems['out'] == 'ecliptic':
# FK5 -> Ecliptic at TDB (MJD) 51544 (i.e. J2000)
lon, lat = slalib.sla_eqecl(lon, lat, 51544)
lons[ii], lats[ii] = lon, lat
return dict(lon=np.degrees(lons), lat=np.degrees(lats))
# FK5 -> FK4 at BEPOCH 2000.0 assuming no proper motion or parallax
r1950, d1950, dr1950, dd1950 = S.sla_fk54z(raj, decj, 2000.0)
vals['FK4'][0][ii], vals['FK4'][1][ii] = r1950, d1950
# FK5 -> Ecliptic at TDB (MJD) 51544.0 (i.e. J2000)
dl, db = S.sla_eqecl(raj, decj, 51544.0)
vals['Ecliptic'][0][ii], vals['Ecliptic'][1][ii] = dl, db
# FK5 -> Galactic
dl, db = S.sla_eqgal(raj, decj)
vals['Galactic'][0][ii], vals['Galactic'][1][ii] = dl, db
# FK5 -> Hipparcos (i.e. ICRF, which is as close as SLALIB
# gets to ICRS) at epoch 2000.0 and with no proper motion
rh, dh = S.sla_fk5hz(raj, decj, 2000.0)
vals['ICRS'][0][ii], vals['ICRS'][1][ii] = rh, dh
glon = vals['Galactic'][0]
glat = vals['Galactic'][1]
np.savetxt('coords_galactic.txt',
zip(np.degrees(glon), np.degrees(glat)),
fmt="%20.15f")
ra_fk4 = vals['FK4'][0]
dec_fk4 = vals['FK4'][1]
np.savetxt('coords_b1950.txt',
zip(np.degrees(ra_fk4), np.degrees(dec_fk4)),
fmt="%20.15f")
elon = vals['Ecliptic'][0]
# FK5 -> FK4 at BEPOCH 2000.0 assuming no proper motion or parallax
r1950, d1950, dr1950, dd1950 = S.sla_fk54z (raj, decj, 2000.0)
vals['FK4'][0][ii],vals['FK4'][1][ii] = r1950, d1950
# FK5 -> Ecliptic at TDB (MJD) 51544.0 (i.e. J2000)
dl, db = S.sla_eqecl(raj, decj, 51544.0)
vals['Ecliptic'][0][ii],vals['Ecliptic'][1][ii] = dl, db
# FK5 -> Galactic
dl, db = S.sla_eqgal(raj, decj)
vals['Galactic'][0][ii],vals['Galactic'][1][ii] = dl, db
# FK5 -> Hipparcos (i.e. ICRF, which is as close as SLALIB
# gets to ICRS) at epoch 2000.0 and with no proper motion
rh, dh = S.sla_fk5hz(raj, decj, 2000.0)
vals['ICRS'][0][ii],vals['ICRS'][1][ii] = rh, dh
glon = vals['Galactic'][0]
glat = vals['Galactic'][1]
np.savetxt('coords_galactic.txt', zip(np.degrees(glon),
np.degrees(glat)), fmt="%20.15f")
ra_fk4 = vals['FK4'][0]
dec_fk4 = vals['FK4'][1]
np.savetxt('coords_b1950.txt', zip(np.degrees(ra_fk4),
np.degrees(dec_fk4)), fmt="%20.15f")
elon = vals['Ecliptic'][0]
elat = vals['Ecliptic'][1]