#
T = jd_to_jcent(jd)
D, M, M1, F, omega = _constants(T)
deltaEps = 0.0
for tD, tM, tM1, tF, tomega, tpsiK, tpsiT, tepsK, tepsT in _tbl:
arg = D*tD + M*tM + M1*tM1 + F*tF + omega*tomega
deltaEps = deltaEps + (tepsK/10000.0 +
tepsT/100000.0 * T) * np.cos(arg)
deltaEps = deltaEps / 3600
deltaEps = d_to_r(deltaEps)
return deltaEps
#
# Constant terms
#
_el0 = (d_to_r(dms_to_d(23, 26, 21.448)),
d_to_r(dms_to_d(0, 0, -46.8150)),
d_to_r(dms_to_d(0, 0, -0.00059)),
d_to_r(dms_to_d(0, 0, 0.001813)))
def obliquity(jd):
"""Return the mean obliquity of the ecliptic.
Low precision, but good enough for most uses. [Meeus-1998: equation 22.2].
Accuracy is 1" over 2000 years and 10" over 4000 years.
Arguments:
- `jd` : Julian Day in dynamical time
Returns:
- latitude in radians
- radius in au
"""
L = self.dimension(jd, planet, "L")
B = self.dimension(jd, planet, "B")
R = self.dimension(jd, planet, "R")
return L, B, R
#
# Constant terms
#
_k0 = d_to_r(-1.397)
_k1 = d_to_r(-0.00031)
_k2 = d_to_r(dms_to_d(0, 0, -0.09033))
_k3 = d_to_r(dms_to_d(0, 0, 0.03916))
def vsop_to_fk5(jd, L, B):
"""Convert VSOP to FK5 coordinates.
This is required only when using the full precision of the
VSOP model. [Meeus-1998: pg 219]
Arguments:
- `jd` : Julian Day in dynamical time
- `L` : longitude in radians
- `B` : latitude in radians
Returns:
def test_geocentric_planet(self):
ra, dec = geocentric_planet(2448976.5, "Venus", d_to_r(dms_to_d(0, 0, 16.749)), d_to_r(23.439669), days_per_second)
np.testing.assert_array_almost_equal(r_to_d(ra), r_to_d(hms_to_fday(21, 4, 41.454) * pi2), decimal=5)
np.testing.assert_almost_equal(r_to_d(dec), dms_to_d(-18, 53, 16.84), decimal=5)
#
T = jd_to_jcent(jd)
D, M, M1, F, omega = _constants(T)
deltaEps = 0.0;
for tD, tM, tM1, tF, tomega, tpsiK, tpsiT, tepsK, tepsT in _tbl:
arg = D*tD + M*tM + M1*tM1 + F*tF + omega*tomega
deltaEps = deltaEps + (tepsK/10000.0 + tepsT/100000.0 * T) * cos(arg)
deltaEps = deltaEps / 3600
deltaEps = d_to_r(deltaEps)
return deltaEps
#
# Constant terms
#
_el0 = (d_to_r(dms_to_d(23, 26, 21.448)),
d_to_r(dms_to_d( 0, 0, -46.8150)),
d_to_r(dms_to_d( 0, 0, -0.00059)),
d_to_r(dms_to_d( 0, 0, 0.001813)))
def obliquity(jd):
"""Return the mean obliquity of the ecliptic.
Low precision, but good enough for most uses. [Meeus-1998: equation 22.2].
Accuracy is 1" over 2000 years and 10" over 4000 years.
Parameters:
jd : Julian Day in dynamical time
Returns:
- `L` : longitude in radians
Returns:
- corrected longitude in radians
"""
jd = np.atleast_1d(jd)
T = jd_to_jcent(jd)
omega = _lk0 - _lk1 * T
return _scalar_if_one(modpi2(L - _lk2 - _lk3 * np.sin(omega)))
#
# Constant terms
#
_lk4 = d_to_r(dms_to_d(0, 0, 20.4898))
def aberration_low(R):
"""Correct for aberration; low precision, but good enough for most uses.
[Meeus-1998: pg 164]
Arguments:
- `R` : radius in au
Returns:
- correction in radians
"""
return -_lk4 / R
- `L` : longitude in radians
Returns:
- corrected longitude in radians
"""
jd = np.atleast_1d(jd)
T = jd_to_jcent(jd)
omega = _lk0 - _lk1 * T
return _scalar_if_one(modpi2(L - _lk2 - _lk3 * np.sin(omega)))
#
# Constant terms
#
_lk4 = d_to_r(dms_to_d(0, 0, 20.4898))
def aberration_low(R):
"""Correct for aberration; low precision, but good enough for most uses.
[Meeus-1998: pg 164]
Arguments:
- `R` : radius in au
Returns:
- correction in radians
"""
return -_lk4 / R
- latitude in radians
- radius in au
"""
L = self.dimension(jd, planet, "L")
B = self.dimension(jd, planet, "B")
R = self.dimension(jd, planet, "R")
return L, B, R
#
# Constant terms
#
_k0 = d_to_r(-1.397)
_k1 = d_to_r(-0.00031)
_k2 = d_to_r(dms_to_d(0, 0, -0.09033))
_k3 = d_to_r(dms_to_d(0, 0, 0.03916))
def vsop_to_fk5(jd, L, B):
"""Convert VSOP to FK5 coordinates.
This is required only when using the full precision of the
VSOP model. [Meeus-1998: pg 219]
Arguments:
- `jd` : Julian Day in dynamical time
- `L` : longitude in radians
- `B` : latitude in radians
Returns: