def _s1_qZ_C2(self, ca1, sa1, ta1, ca2, sa2, ta2):
'''(INTERNAL) Compute C{sm1 / (s / qZ)} and C{C} for .__init__.
'''
E = self.datum.ellipsoid
b_a = E.b_a
e2 = E.e2
tb1 = b_a * ta1
tb2 = b_a * ta2
dtb12 = b_a * (tb1 + tb2)
scb12 = _1_0 + tb1**2
scb22 = _1_0 + tb2**2
esa1_2 = (_1_0 - e2 * sa1**2) \
* (_1_0 - e2 * sa2**2)
esa12 = _1_0 + e2 * sa1 * sa2
dsn = _Dsn(ta2, ta1, sa2, sa1)
axi, bxi, sxi = self._a_b_sxi3((ca1, sa1, ta1, scb12),
(ca2, sa2, ta2, scb22))
dsxi = (esa12 / esa1_2 + self._Datanhee(sa2, sa1)) * dsn / (_2_0 *
self._qx)
C = fsum_(sxi * dtb12 / dsxi, scb22, scb12) / (_2_0 * scb22 * scb12)
sa12 = fsum_(sa1, sa2, sa1 * sa2)
axi *= (_1_0 + e2 * sa12) / (_1_0 + sa12)
bxi *= e2 * fsum_(sa1, sa2, esa12) / esa1_2 + E.e12 * self._D2atanhee(
sa1, sa2)
s1_qZ = dsn * (axi * self._qZ - bxi) / (_2_0 * dtb12)
return s1_qZ, C
def thomas_(phi2, phi1, lam21, datum=Datums.WGS84):
'''Compute the I{angular} distance between two (ellipsoidal) points using
U{Thomas'<https://apps.DTIC.mil/dtic/tr/fulltext/u2/703541.pdf>}
formula.
@arg phi2: End latitude (C{radians}).
@arg phi1: Start latitude (C{radians}).
@arg lam21: Longitudinal delta, M{end-start} (C{radians}).
@kwarg datum: Ellipsoidal datum to use (L{Datum}).
@return: Angular distance (C{radians}).
@raise TypeError: Invalid B{C{datum}}.
@see: Functions L{thomas}, L{cosineAndoyerLambert_},
L{cosineForsytheAndoyerLambert_}, L{cosineLaw_},
L{equirectangular_}, L{euclidean_}, L{flatLocal_}/L{hubeny_},
L{flatPolar_}, L{haversine_} and L{vincentys_} and U{Geodesy-PHP
<https://GitHub.com/jtejido/geodesy-php/blob/master/src/Geodesy/
Distance/ThomasFormula.php>}.
'''
_xinstanceof(Datum, datum=datum)
s2, c2, s1, c1, _, c21 = sincos2(phi2, phi1, lam21)
E = datum.ellipsoid
if E.f and abs(c1) > EPS and abs(c2) > EPS:
r1 = atan(E.b_a * s1 / c1)
r2 = atan(E.b_a * s2 / c2)
j = (r2 + r1) / 2.0
k = (r2 - r1) / 2.0
sj, cj, sk, ck, sl_2, _ = sincos2(j, k, lam21 / 2.0)
h = fsum_(sk**2, (ck * sl_2)**2, -(sj * sl_2)**2)
if EPS < abs(h) < EPS1:
u = 1 / (1 - h)
d = 2 * atan(sqrt(h * u)) # == acos(1 - 2 * h)
sd, cd = sincos2(d)
if abs(sd) > EPS:
u = 2 * (sj * ck)**2 * u
v = 2 * (sk * cj)**2 / h
x = u + v
y = u - v
t = d / sd
s = 4 * t**2
e = 2 * cd
a = s * e
b = 2 * d
c = t - (a - e) / 2.0
s = fsum_(a * x, c * x**2, -b * y, -e * y**2,
s * x * y) * E.f / 16.0
s = fsum_(t * x, -y, -s) * E.f / 4.0
return d - s * sd
# fall back to cosineLaw_
return acos(s1 * s2 + c1 * c2 * c21)
def reverse(self, xyz, y=None, z=None, **no_M): # PYCHOK unused M
'''Convert from geocentric C{(x, y, z)} to geodetic C{(lat, lon, height)}
using I{Rey-Jer You}'s transformation.
@arg xyz: Either an L{Ecef9Tuple}, an C{(x, y, z)} 3-tuple or C{scalar}
ECEF C{x} coordinate in C{meter}.
@kwarg y: ECEF C{y} coordinate in C{meter} for C{scalar} B{C{xyz}}
and B{C{z}}.
@kwarg z: ECEF C{z} coordinate in C{meter} for C{scalar} B{C{xyz}}
and B{C{y}}.
@kwarg no_M: Rotation matrix C{M} not available.
@return: An L{Ecef9Tuple}C{(x, y, z, lat, lon, height, C, M, datum)}
with geodetic coordinates C{(lat, lon, height)} for the given
geocentric ones C{(x, y, z)}, case C{C} 1, L{EcefMatrix} C{M}
always C{None} and C{datum} if available.
@raise EcefError: If B{C{xyz}} not L{Ecef9Tuple} or C{scalar} C{x}
or B{C{y}} and/or B{C{z}} not C{scalar} for C{scalar}
B{C{xyz}}.
'''
x, y, z, name = _xyzn4(xyz, y, z, Error=EcefError)
x2, y2, z2 = x**2, y**2, z**2
r2 = fsum_(x2, y2, z2) # = hypot3(x2, y2, z2)**2
E = self.ellipsoid
e = sqrt(E.a2 - E.b2)
e2 = e**2
u = sqrt(fsum_(r2, -e2, hypot(r2 - e2, 2 * e * z)) / 2)
p = hypot(u, e)
q = hypot(x, y)
B = atan2(p * z, u * q) # beta0 = atan(p / u * z / q)
sB, cB = sincos2(B)
p *= E.a
B += fsum_(u * E.b, -p, e2) * sB / (p / cB - e2 * cB)
sB, cB = sincos2(B)
h = hypot(z - E.b * sB, q - E.a * cB)
if fsum_(x2, y2, z2 * E.a_b**2) < E.a2:
h = -h # inside ellipsoid
r = Ecef9Tuple(
x,
y,
z,
degrees(atan2(E.a * sB, E.b * cB)), # atan(E.a_b * tan(B))
degrees(atan2(y, x)),
h,
1, # C=1
None, # M=None
self.datum)
return self._xnamed(r, name)
def _Hf(e0, e1, e2, e3, e4, e5):
'''(INTERNAL) Horner form for C{_RD} and C{_RJ} below.
'''
# Polynomial is <https://DLMF.NIST.gov/19.36.E2>
# (1 - 3*E2/14 + E3/6 + 9*E2^2/88 - 3*E4/22 - 9*E2*E3/52 + 3*E5/26
# - E2^3/16 + 3*E3^2/40 + 3*E2*E4/20 + 45*E2^2*E3/272
# - 9*(E3*E4+E2*E5)/68)
return fsum_(
fsum_(471240, -540540 * e2) * e5,
fsum_(612612 * e2, -540540 * e3, -556920) * e4,
fsum_(306306 * e3, 675675 * e2**2, -706860 * e2, 680680) * e3,
fsum_(417690 * e2, -255255 * e2**2, -875160) * e2,
4084080) / (4084080 * e1) + e0
def cosineForsytheAndoyerLambert_(phi2, phi1, lam21, datum=Datums.WGS84):
'''Compute the I{angular} distance between two (ellipsoidal) points using the
U{Forsythe-Andoyer-Lambert correction<https://www2.UNB.CA/gge/Pubs/TR77.pdf>} of
the U{Law of Cosines<https://www.Movable-Type.co.UK/scripts/latlong.html#cosine-law>}
formula.
@arg phi2: End latitude (C{radians}).
@arg phi1: Start latitude (C{radians}).
@arg lam21: Longitudinal delta, M{end-start} (C{radians}).
@kwarg datum: Ellipsoidal datum to use (L{Datum}).
@return: Angular distance (C{radians}).
@raise TypeError: Invalid B{C{datum}}.
@see: Functions L{cosineForsytheAndoyerLambert}, L{cosineAndoyerLambert_},
L{cosineLaw_}, L{equirectangular_}, L{euclidean_}, L{flatLocal_}/L{hubeny_},
L{flatPolar_}, L{haversine_}, L{thomas_} and L{vincentys_} and U{Geodesy-PHP
<https://GitHub.com/jtejido/geodesy-php/blob/master/src/Geodesy/
Distance/ForsytheCorrection.php>}.
'''
_xinstanceof(Datum, datum=datum)
s2, c2, s1, c1, _, c21 = sincos2(phi2, phi1, lam21)
r = acos(s1 * s2 + c1 * c2 * c21)
E = datum.ellipsoid
if E.f:
sr, cr, s2r, _ = sincos2(r, r * 2)
if abs(sr) > EPS:
r2 = r**2
p = (s1 + s2)**2 / (1 + cr)
q = (s1 - s2)**2 / (1 - cr)
x = p + q
y = p - q
s = 8 * r2 / sr
a = 64 * r + 2 * s * cr # 16 * r2 / tan(r)
d = 48 * sr + s # 8 * r2 / tan(r)
b = -2 * d
e = 30 * s2r
c = fsum_(30 * r, e / 2, s * cr) # 8 * r2 / tan(r)
d = fsum_(a * x, b * y, -c * x**2, d * x * y,
e * y**2) * E.f / 32.0
d = fsum_(d, -x * r, 3 * y * sr) * E.f / 4.0
r += d
return r
def heightOf(angle, distance, radius=R_M):
'''Determine the height above the (spherical) earth after
traveling along a straight line at a given tilt.
@param angle: Tilt angle above horizontal (C{degrees}).
@param distance: Distance along the line (C{meter} or same units
as B{C{radius}}).
@keyword radius: Optional mean earth radius (C{meter}).
@return: Height (C{meter}, same units as B{C{distance}} and B{C{radius}}).
@raise ValueError: Invalid B{C{angle}}, B{C{distance}} or B{C{radius}}.
@see: U{MultiDop geog_lib.GeogBeamHt<https://GitHub.com/NASA/MultiDop>}
(U{Shapiro et al. 2009, JTECH
<https://Journals.AMetSoc.org/doi/abs/10.1175/2009JTECHA1256.1>}
and U{Potvin et al. 2012, JTECH
<https://Journals.AMetSoc.org/doi/abs/10.1175/JTECH-D-11-00019.1>}).
'''
d, r = distance, radius
if d > r:
d, r = r, d
if d > EPS:
d = d / float(r)
s = sin(radians(angle))
s = fsum_(1, 2 * s * d, d**2)
if s > 0:
return r * sqrt(s) - float(radius)
raise ValueError('%s%r' % ('heightOf', (angle, distance, radius)))
def _RD(x, y, z): # used by testElliptic.py
'''Degenerate symmetric integral of the third kind C{_RD}.
@return: C{_RD(x, y, z) = _RJ(x, y, z, z)}.
@see: U{C{_RD} definition<https://DLMF.NIST.gov/19.16.E5>}.
'''
# Carlson, eqs 2.28 - 2.34
m = 1.0
S = Fsum()
A = fsum_(x, y, z, z, z) * 0.2
T = (A, x, y, z)
Q = _Q(A, T, _TolRD)
for _ in range(_TRIPS):
if Q < abs(m * T[0]): # max 7 trips
break
t = T[3] # z0
r, s, T = _rsT(T)
S += 1.0 / (m * s[2] * (t + r))
m *= 4
else:
raise _convergenceError(_RD, x, y, z)
m *= T[0] # An
x = (x - A) / m
y = (y - A) / m
z = (x + y) / 3.0
z2 = z**2
xy = x * y
return _Horner(3 * S.fsum(), m * sqrt(T[0]),
xy - 6 * z2,
(xy * 3 - 8 * z2) * z,
(xy - z2) * 3 * z2,
xy * z2 * z)
def _RG(x, y, z=None):
'''Symmetric integral of the second kind C{_RG}.
@return: C{_RG(x, y, z)}.
@see: U{C{_RG} definition<https://DLMF.NIST.gov/19.16.E3>}
and in Carlson, eq. 1.5.
'''
if z is None:
# Carlson, eqs 2.36 - 2.39
a, b = sqrt(x), sqrt(y)
if a < b:
a, b = b, a
S = Fsum(0.25 * (a + b)**2)
m = -0.25 # note, negative
while abs(a - b) > (_tolRG0 * a): # max 4 trips
b, a = sqrt(a * b), (a + b) * 0.5
m *= 2
S.fadd_(m * (a - b)**2)
return S.fsum() * PI_2 / (a + b)
if not z:
y, z = z, y
# Carlson, eq 1.7
return fsum_(
_RF(x, y, z) * z,
_RD_3(x, y, z) * (x - z) * (z - y), sqrt(x * y / z)) * 0.5
def _RF(x, y, z): # used by testElliptic.py
'''Symmetric integral of the first kind C{_RF}.
@return: C{_RF(x, y, z)}.
@see: U{C{_RF} definition<https://DLMF.NIST.gov/19.16.E1>}.
'''
# Carlson, eqs 2.2 - 2.7
m = 1.0
A = fsum_(x, y, z) / 3.0
T = (A, x, y, z)
Q = _Q(A, T, _TolRF)
for _ in range(_TRIPS):
if Q < abs(m * T[0]): # max 6 trips
break
_, _, T = _rsT(T)
m *= 4
else:
raise _convergenceError(_RF, x, y, z)
m *= T[0] # An
x = (A - x) / m
y = (A - y) / m
z = -(x + y)
e2 = x * y - z**2
e3 = x * y * z
# Polynomial is <https://DLMF.NIST.gov/19.36.E1>
# (1 - E2/10 + E3/14 + E2**2/24 - 3*E2*E3/44
# - 5*E2**3/208 + 3*E3**2/104 + E2**2*E3/16)
# converted to Horner form ...
H = Fsum( 6930 * e3, 15015 * e2**2, -16380 * e2, 17160) * e3
H += Fsum(10010 * e2, -5775 * e2**2, -24024) * e2
return H.fsum_(240240) / (240240 * sqrt(T[0]))
def heightOf(angle, distance, radius=R_M):
'''Determine the height above the (spherical) earth after
traveling along a straight line at a given tilt.
@arg angle: Tilt angle above horizontal (C{degrees}).
@arg distance: Distance along the line (C{meter} or same units as
B{C{radius}}).
@kwarg radius: Optional mean earth radius (C{meter}).
@return: Height (C{meter}, same units as B{C{distance}} and B{C{radius}}).
@raise ValueError: Invalid B{C{angle}}, B{C{distance}} or B{C{radius}}.
@see: U{MultiDop geog_lib.GeogBeamHt<https://GitHub.com/NASA/MultiDop>}
(U{Shapiro et al. 2009, JTECH
<https://Journals.AMetSoc.org/doi/abs/10.1175/2009JTECHA1256.1>}
and U{Potvin et al. 2012, JTECH
<https://Journals.AMetSoc.org/doi/abs/10.1175/JTECH-D-11-00019.1>}).
'''
r = h = Radius(radius)
d = abs(Distance(distance))
if d > h:
d, h = h, d
if d > EPS:
d = d / h # PyChecker chokes on ... /= ...
s = sin(Phi_(angle, name='angle', clip=180))
s = fsum_(1, 2 * s * d, d**2)
if s > 0:
return h * sqrt(s) - r
raise InvalidError(angle=angle, distance=distance, radius=radius)
def flatPolar_(phi2, phi1, lam21):
'''Compute the I{angular} distance between two (spherical) points
using the U{polar coordinate flat-Earth<https://WikiPedia.org/wiki/
Geographical_distance#Polar_coordinate_flat-Earth_formula>}
formula.
@arg phi2: End latitude (C{radians}).
@arg phi1: Start latitude (C{radians}).
@arg lam21: Longitudinal delta, M{end-start} (C{radians}).
@return: Angular distance (C{radians}).
@see: Functions L{flatPolar}, L{cosineAndoyerLambert_},
L{cosineForsytheAndoyerLambert_}, L{cosineLaw_},
L{equirectangular_}, L{euclidean_}, L{flatLocal_}/L{hubeny_},
L{haversine_}, L{thomas_} and L{vincentys_}.
'''
a1 = abs(PI_2 - phi1) # co-latitude
a2 = abs(PI_2 - phi2) # co-latitude
ab = abs(2 * a1 * a2 * cos(lam21))
a = max(a1, a2, ab)
if a > EPS:
s = fsum_((a1 / a)**2, (a2 / a)**2, -ab / a**2)
a *= sqrt(s) if s > 0 else 0
return a
def _intersects2(center1, r1, center2, r2, sphere=True, too_d=None, # in .ellipsoidalBase._intersections2
Vector=None, **Vector_kwds):
# (INTERNAL) Intersect two spheres or circles, see L{intersections2}
# above, separated to allow callers to embellish any exceptions
def _V3(x, y, z):
v = Vector3d(x, y, z)
n = intersections2.__name__
return _V_n(v, n, Vector, Vector_kwds)
def _xV3(c1, u, x, y):
xy1 = x, y, _1_0 # transform to original space
return _V3(fdot(xy1, u.x, -u.y, c1.x),
fdot(xy1, u.y, u.x, c1.y), _0_0)
c1 = _otherV3d(sphere=sphere, center1=center1)
c2 = _otherV3d(sphere=sphere, center2=center2)
if r1 < r2: # r1, r2 == R, r
c1, c2 = c2, c1
r1, r2 = r2, r1
m = c2.minus(c1)
d = m.length
if d < max(r2 - r1, EPS):
raise ValueError(_near_concentric_)
o = fsum_(-d, r1, r2) # overlap == -(d - (r1 + r2))
# compute intersections with c1 at (0, 0) and c2 at (d, 0), like
# <https://MathWorld.Wolfram.com/Circle-CircleIntersection.html>
if o > EPS: # overlapping, r1, r2 == R, r
x = _radical2(d, r1, r2).xline
y = _1_0 - (x / r1)**2
if y > EPS:
y = r1 * sqrt(y) # y == a / 2
elif y < 0:
raise ValueError(_invalid_)
else: # abutting
y = _0_0
elif o < 0:
t = d if too_d is None else too_d
raise ValueError(_too_(Fmt.distant(t)))
else: # abutting
x, y = r1, _0_0
u = m.unit()
if sphere: # sphere center and radius
c = c1 if x < EPS else (
c2 if x > EPS1 else c1.plus(u.times(x)))
t = _V3(c.x, c.y, c.z), Radius(y)
elif y > 0: # intersecting circles
t = _xV3(c1, u, x, y), _xV3(c1, u, x, -y)
else: # abutting circles
t = _xV3(c1, u, x, 0)
t = t, t
return t
def _RF(x, y, z=None):
'''Symmetric integral of the first kind C{_RF}.
@return: C{_RF(x, y, z)}.
@see: U{C{_RF} definition<https://DLMF.NIST.gov/19.16.E1>}.
'''
if z is None:
# Carlson, eqs 2.36 - 2.38
a, b = sqrt(x), sqrt(y)
if a < b:
a, b = b, a
while abs(a - b) > (_tolRG0 * a): # max 4 trips
b, a = sqrt(a * b), (a + b) * 0.5
return PI / (a + b)
# Carlson, eqs 2.2 - 2.7
m = 1.0
A = fsum_(x, y, z) / 3.0
T = [A, x, y, z]
Q = _Q(A, T, _tolRF)
for _ in range(_TRIPS):
if Q < abs(m * T[0]): # max 6 trips
break
_, _, T = _rsT(T)
m *= 4
else:
raise EllipticError('no %s convergence' % ('RF', ))
m *= T[0] # An
x = (A - x) / m
y = (A - y) / m
z = -(x + y)
e2 = x * y - z**2
e3 = x * y * z
# Polynomial is <https://DLMF.NIST.gov/19.36.E1>
# (1 - E2/10 + E3/14 + E2^2/24 - 3*E2*E3/44
# - 5*E2^3/208 + 3*E3^2/104 + E2^2*E3/16)
# convert to Horner form ...
return fsum_(
fsum_(6930 * e3, 15015 * e2**2, -16380 * e2, 17160) * e3,
fsum_(10010 * e2, -5775 * e2**2, -24024) * e2,
240240) / (240240 * sqrt(T[0]))
def _RJ(x, y, z, p): # used by testElliptic.py
'''Symmetric integral of the third kind C{_RJ(x, y, z, p)}.
@return: C{_RJ(x, y, z, p)}.
@see: U{C{_RJ} definition<https://DLMF.NIST.gov/19.16.E2>} and
U{Carlson<https://ArXiv.org/pdf/math/9409227.pdf>}.
'''
def _xyzp(x, y, z, p):
return (x + p) * (y + p) * (z + p)
# Carlson, eqs 2.17 - 2.25
m = m3 = _1_0
S = Fsum()
D = neg(_xyzp(x, y, z, -p))
A = fsum_(x, y, z, 2 * p) * _0_2
T = (A, x, y, z, p)
Q = _Q(A, T, _TolRD)
for _ in range(_TRIPS):
if Q < abs(m * T[0]): # max 7 trips
break
_, s, T = _rsT(T)
d = _xyzp(*s)
e = D / (m3 * d**2)
S += _RC(1, 1 + e) / (m * d)
m *= _4_0
m3 *= 64
else:
raise _convergenceError(_RJ, x, y, z, p)
m *= T[0] # An
x = (A - x) / m
y = (A - y) / m
z = (A - z) / m
xyz = x * y * z
p = neg(x + y + z) * _0_5
p2 = p**2
e2 = fsum_(x * y, x * z, y * z, -3 * p2)
return _horner(6 * S.fsum(), m * sqrt(T[0]), e2,
fsum_(xyz, 2 * p * e2, 4 * p * p2),
fsum_(xyz * 2, p * e2, 3 * p * p2) * p,
p2 * xyz)
def _RJ(x, y, z, p):
'''Symmetric integral of the third kind C{_RJ}.
@return: C{_RJ(x, y, z, p)}.
@see: U{C{_RJ} definition<https://DLMF.NIST.gov/19.16.E2>}.
'''
def _xyzp(x, y, z, p):
return (x + p) * (y + p) * (z + p)
# Carlson, eqs 2.17 - 2.25
m = m3 = 1.0
S = Fsum()
D = -_xyzp(x, y, z, -p)
A = fsum_(x, y, z, 2 * p) * 0.2
T = [A, x, y, z, p]
Q = _Q(A, T, _tolRD)
for _ in range(_TRIPS):
if Q < abs(m * T[0]): # max 7 trips
break
_, s, T = _rsT(T)
d = _xyzp(*s)
e = D / (m3 * d**2)
S.fadd_(_RC(1, 1 + e) / (m * d))
m *= 4
m3 *= 64
else:
raise EllipticError('no %s convergence' % ('RJ', ))
S *= 6
m *= T[0] # An
x = (A - x) / m
y = (A - y) / m
z = (A - z) / m
xyz = x * y * z
p = -(x + y + z) * 0.5
p2 = p**2
e2 = fsum_(x * y, x * z, y * z, -3 * p2)
return _Hf(S.fsum(), m * sqrt(T[0]), e2, fsum_(xyz, 2 * p * e2,
4 * p * p2),
fsum_(xyz * 2, p * e2, 3 * p * p2) * p, p2 * xyz)
def _fE(sn, cn, dn):
sn2, cn2, dn2 = sn**2, cn**2, dn**2
kp2, k2 = self.kp2, self.k2
if k2 <= 0: # Carlson, eq. 4.6, <https://DLMF.NIST.gov/19.25.E9>
ei = _RF(cn2, dn2, 1) - k2 * sn2 * _RD_3(cn2, dn2, 1)
elif kp2 >= 0: # <https://DLMF.NIST.gov/19.25.E10>
ei = fsum_(kp2 * _RF(cn2, dn2, 1),
kp2 * k2 * sn2 * _RD_3(cn2, 1, dn2),
k2 * abs(cn) / dn)
else: # <https://DLMF.NIST.gov/19.25.E11>
ei = dn / abs(cn) - kp2 * sn2 * _RD_3(dn2, 1, cn2)
return ei * abs(sn)
def to3llh(self, datum=Datums.WGS84):
'''Convert this (geocentric) Cartesian (x/y/z) point to
(ellipsoidal, geodetic) lat-, longitude and height on
the given datum.
Uses B. R. Bowring’s formulation for μm precision in concise
form: U{'The accuracy of geodetic latitude and height equations'
<https://www.ResearchGate.net/publication/
233668213_The_Accuracy_of_Geodetic_Latitude_and_Height_Equations>},
Survey Review, Vol 28, 218, Oct 1985.
See also Ralph M. Toms U{'An Efficient Algorithm for Geocentric to
Geodetic Coordinate Conversion'<https://www.OSTI.gov/scitech/biblio/110235>},
Sept 1995 and U{'An Improved Algorithm for Geocentric to Geodetic Coordinate
Conversion'<https://www.OSTI.gov/scitech/servlets/purl/231228>},
Apr 1996, from Lawrence Livermore National Laboratory.
@keyword datum: Optional datum to use (L{Datum}).
@return: A L{LatLon3Tuple}C{(lat, lon, height)}.
'''
E = datum.ellipsoid
x, y, z = self.to3xyz()
p = hypot(x, y) # distance from minor axis
r = hypot(p, z) # polar radius
if min(p, r) > EPS:
# parametric latitude (Bowring eqn 17, replaced)
t = (E.b * z) / (E.a * p) * (1 + E.e22 * E.b / r)
c = 1 / hypot1(t)
s = t * c
# geodetic latitude (Bowring eqn 18)
a = atan2(z + E.e22 * E.b * s**3, p - E.e2 * E.a * c**3)
b = atan2(y, x) # ... and longitude
# height above ellipsoid (Bowring eqn 7)
sa, ca = sincos2(a)
# r = E.a / E.e2s(sa) # length of normal terminated by minor axis
# h = p * ca + z * sa - (E.a * E.a / r)
h = fsum_(p * ca, z * sa, -E.a * E.e2s(sa))
a, b = degrees90(a), degrees180(b)
# see <https://GIS.StackExchange.com/questions/28446>
elif p > EPS: # latitude arbitrarily zero
a, b, h = 0.0, degrees180(atan2(y, x)), p - E.a
else: # polar latitude, longitude arbitrarily zero
a, b, h = copysign(90.0, z), 0.0, abs(z) - E.b
return self._xnamed(LatLon3Tuple(a, b, h))
def _RG(x, y, z): # used by testElliptic.py
'''Symmetric integral of the second kind C{_RG(x, y, z)}.
@return: C{_RG(x, y, z)}.
@see: U{C{_RG} definition<https://DLMF.NIST.gov/19.16.E3>} and
U{Carlson<https://ArXiv.org/pdf/math/9409227.pdf>}.
'''
if not z:
y, z = z, y
# Carlson, eq 1.7
return fsum_(_RF(x, y, z) * z,
_RD_3(x, y, z) * (x - z) * (z - y),
sqrt(x * y / z)) * _0_5
def _RG(x, y, z): # used by testElliptic.py
'''Symmetric integral of the second kind C{_RG}.
@return: C{_RG(x, y, z)}.
@see: U{C{_RG} definition<https://DLMF.NIST.gov/19.16.E3>}
and in Carlson, eq. 1.5.
'''
if not z:
y, z = z, y
# Carlson, eq 1.7
return fsum_(_RF(x, y, z) * z,
_RD_3(x, y, z) * (x - z) * (z - y),
sqrt(x * y / z)) * 0.5
def _intersects2(c1, rad1, c2, rad2, radius=R_M, # in .ellipsoidalBase._intersects2
height=None, wrap=True, too_d=None,
LatLon=LatLon, **LatLon_kwds):
# (INTERNAL) Intersect two spherical circles, see L{intersections2}
# above, separated to allow callers to embellish any exceptions
def _dest3(bearing, h):
a, b = _destination2(a1, b1, r1, bearing)
return _latlon3(degrees90(a), degrees180(b), h,
intersections2, LatLon, **LatLon_kwds)
r1, r2, f = _rads3(rad1, rad2, radius)
if f: # swapped
c1, c2 = c2, c1 # PYCHOK swap
a1, b1 = c1.philam
a2, b2 = c2.philam
db, b2 = unrollPI(b1, b2, wrap=wrap)
d = vincentys_(a2, a1, db) # radians
if d < max(r1 - r2, EPS):
raise ValueError(_near_concentric_)
x = fsum_(r1, r2, -d) # overlap
if x > EPS:
sd, cd, sr1, cr1, _, cr2 = sincos2(d, r1, r2)
x = sd * sr1
if abs(x) < EPS:
raise ValueError(_invalid_)
x = acos1((cr2 - cd * cr1) / x) # 0 <= x <= PI
elif x < 0:
t = (d * radius) if too_d is None else too_d
raise ValueError(_too_distant_fmt_ % (t,))
if height is None: # "radical height"
f = _radical2(d, r1, r2).ratio
h = Height(favg(c1.height, c2.height, f=f))
else:
h = Height(height)
b = bearing_(a1, b1, a2, b2, final=False, wrap=wrap)
if x < _EPS_I2: # externally ...
r = _dest3(b, h)
elif x > _PI_EPS_I2: # internally ...
r = _dest3(b + PI, h)
else:
return _dest3(b + x, h), _dest3(b - x, h)
return r, r # ... abutting circles
def intersect(self, p1, p2, edge): # compute intersection
# of polygon edge p1 to p2 and the current clip edge,
# where p1 and p2 are known to NOT be located on the
# same side of or on the current clip edge
# <https://StackOverflow.com/questions/563198/
# how-do-you-detect-where-two-line-segments-intersect>
fy = float(p2.lat - p1.lat)
fx = float(p2.lon - p1.lon)
fp = fy * self._dx - fx * self._dy
if abs(fp) < EPS:
raise AssertionError('clipSH.intersect')
h = fsum_(self._xy, -p1.lat * self._dx, p1.lon * self._dy) / fp
y = p1.lat + h * fy
x = p1.lon + h * fx
return _LLi_(y, x, p1.classof, edge)
def toNvector(self,
Nvector=None,
datum=None,
**kwds): # PYCHOK Datums.WGS84
'''Convert this cartesian to C{n-vector} components.
@keyword Nvector: Optional (sub-)class to return the
C{n-vector} components (C{Nvector})
or C{None}.
@keyword datum: Optional datum (L{Datum}) overriding this
cartesian's datum.
@keyword kwds: Optional, additional B{C{Nvector}} keyword
arguments, ignored if C{B{Nvector}=None}.
@return: Unit vector B{C{Nvector}} or a L{Vector4Tuple}C{(x,
y, z, h)} if B{C{Nvector}=None}.
@raise ValueError: The B{C{Cartesian}} at origin.
'''
d = datum or self.datum
r = self._v4t
if r is None or self.datum != d:
E = d.ellipsoid
x, y, z = self.to3xyz()
# Kenneth Gade eqn 23
p = hypot2(x, y) * E.a2_
q = (z**2 * E.e12) * E.a2_
r = fsum_(p, q, -E.e4) / 6
s = (p * q * E.e4) / (4 * r**3)
t = cbrt(fsum_(1, s, sqrt(s * (2 + s))))
u = r * fsum_(1, t, 1 / t)
v = sqrt(u**2 + E.e4 * q)
w = E.e2 * fsum_(u, v, -q) / (2 * v)
k = sqrt(fsum_(u, v, w**2)) - w
if abs(k) < EPS:
raise ValueError('%s: %r' % ('origin', self))
e = k / (k + E.e2)
t = hypot(e * hypot(x, y), z)
if t < EPS:
raise ValueError('%s: %r' % ('origin', self))
h = fsum_(k, E.e2, -1) / k * t
s = e / t
r = Vector4Tuple(x * s, y * s, z / t, h)
self._v4t = r if d == self.datum else None
if Nvector is not None:
r = Nvector(r.x, r.y, r.z, h=r.h, datum=d, **kwds)
return self._xnamed(r)
def rhumbMidpointTo(self, other, height=None):
'''Return the (loxodromic) midpoint between this and
an other point.
@arg other: The other point (spherical LatLon).
@kwarg height: Optional height, overriding the mean height
(C{meter}).
@return: The midpoint (spherical C{LatLon}).
@raise TypeError: The I{other} point is not spherical.
@raise ValueError: Invalid B{C{height}}.
@example:
>>> p = LatLon(51.127, 1.338)
>>> q = LatLon(50.964, 1.853)
>>> m = p.rhumb_midpointTo(q)
>>> m.toStr() # '51.0455°N, 001.5957°E'
'''
self.others(other)
# see <https://MathForum.org/library/drmath/view/51822.html>
a1, b1 = self.philam
a2, b2 = other.philam
if abs(b2 - b1) > PI:
b1 += PI2 # crossing anti-meridian
a3 = favg(a1, a2)
b3 = favg(b1, b2)
f1 = tanPI_2_2(a1)
if abs(f1) > EPS:
f2 = tanPI_2_2(a2)
f = f2 / f1
if abs(f) > EPS:
f = log(f)
if abs(f) > EPS:
f3 = tanPI_2_2(a3)
b3 = fsum_(b1 * log(f2), -b2 * log(f1),
(b2 - b1) * log(f3)) / f
h = self._havg(other) if height is None else Height(height)
return self.classof(degrees90(a3), degrees180(b3), height=h)
def toNvector(self, datum=Datums.WGS84):
'''Convert this cartesian to an (ellipsoidal) n-vector.
@keyword datum: Optional datum to use (L{Datum}).
@return: The ellipsoidal n-vector (L{Nvector}).
@raise ValueError: The B{C{Cartesian}} at origin.
@example:
>>> from ellipsoidalNvector import LatLon
>>> c = Cartesian(3980581, 97, 4966825)
>>> n = c.toNvector() # (0.62282, 0.000002, 0.78237, +0.24)
'''
if self._Nv is None or datum != self._Nv.datum:
E = datum.ellipsoid
x, y, z = self.to3xyz()
# Kenneth Gade eqn 23
p = (x**2 + y**2) * E.a2_
q = (z**2 * E.e12) * E.a2_
r = fsum_(p, q, -E.e4) / 6
s = (p * q * E.e4) / (4 * r**3)
t = cbrt(fsum_(1, s, sqrt(s * (2 + s))))
u = r * fsum_(1, t, 1 / t)
v = sqrt(u**2 + E.e4 * q)
w = E.e2 * fsum_(u, v, -q) / (2 * v)
k = sqrt(fsum_(u, v, w**2)) - w
if abs(k) < EPS:
raise ValueError('%s: %r' % ('origin', self))
e = k / (k + E.e2)
d = e * hypot(x, y)
t = hypot(d, z)
if t < EPS:
raise ValueError('%s: %r' % ('origin', self))
h = fsum_(k, E.e2, -1) / k * t
s = e / t
self._Nv = Nvector(x * s,
y * s,
z / t,
h=h,
datum=datum,
name=self.name)
return self._Nv
def horizon(height, radius=R_M, refraction=False):
'''Determine the distance to the horizon from a given altitude
above the (spherical) earth.
@param height: Altitude (C{meter} or same units as B{C{radius}}).
@keyword radius: Optional mean earth radius (C{meter}).
@keyword refraction: Consider atmospheric refraction (C{bool}).
@return: Distance (C{meter}, same units as B{C{height}} and B{C{radius}}).
@raise ValueError: Invalid B{C{height}} or B{C{radius}}.
@see: U{Distance to horizon<https://www.EdWilliams.org/avform.htm#Horizon>}.
'''
if min(height, radius) < 0:
raise ValueError('%s%r' % ('horizon', (height, radius)))
if refraction:
d2 = 2.415750694528 * height * radius # 2.0 / 0.8279
else:
d2 = height * fsum_(radius, radius, height)
return sqrt(d2)
def horizon(height, radius=R_M, refraction=False):
'''Determine the distance to the horizon from a given altitude
above the (spherical) earth.
@arg height: Altitude (C{meter} or same units as B{C{radius}}).
@kwarg radius: Optional mean earth radius (C{meter}).
@kwarg refraction: Consider atmospheric refraction (C{bool}).
@return: Distance (C{meter}, same units as B{C{height}} and B{C{radius}}).
@raise ValueError: Invalid B{C{height}} or B{C{radius}}.
@see: U{Distance to horizon<https://www.EdWilliams.org/avform.htm#Horizon>}.
'''
h, r = Height(height), Radius(radius)
if min(h, r) < 0:
raise InvalidError(height=height, radius=radius)
if refraction:
d2 = 2.415750694528 * h * r # 2.0 / 0.8279
else:
d2 = h * fsum_(r, r, h)
return sqrt(d2)
def _scaled(self, tau, d2, snu, cnu, dnu, snv, cnv, dnv):
'''(INTERNAL) C{scaled}.
@note: Argument B{C{d2}} is C{_mu * cnu**2 + _mv * cnv**2}
from C{._sigma3} or C{._zeta3}.
@return: 2-Tuple C{(convergence, scale)}.
@see: C{void TMExact::Scale(real tau, real /*lam*/,
real snu, real cnu, real dnu,
real snv, real cnv, real dnv,
real &gamma, real &k)}.
'''
mu, mv = self._mu, self._mv
cnudnv = cnu * dnv
# Lee 55.12 -- negated for our sign convention. g gives
# the bearing (clockwise from true north) of grid north
g = atan2(mv * cnv * snv * snu, cnudnv * dnu)
# Lee 55.13 with nu given by Lee 9.1 -- in sqrt change
# the numerator from
#
# (1 - snu^2 * dnv^2) to (_mv * snv^2 + cnu^2 * dnv^2)
#
# to maintain accuracy near phi = 90 and change the
# denomintor from
# (dnu^2 + dnv^2 - 1) to (_mu * cnu^2 + _mv * cnv^2)
#
# to maintain accuracy near phi = 0, lam = 90 * (1 - e).
# Similarly rewrite sqrt term in 9.1 as
#
# _mv + _mu * c^2 instead of 1 - _mu * sin(phi)^2
q2 = (mv * snv**2 + cnudnv**2) / d2
# originally: sec2 = 1 + tau**2 # sec(phi)^2
# k = sqrt(mv + mu / sec2) * sqrt(sec2) * sqrt(q2)
# = sqrt(mv + mv * tau**2 + mu) * sqrt(q2)
k = sqrt(fsum_(mu, mv, mv * tau**2)) * sqrt(q2)
return degrees(g), k * self._k0
def toOsgr(latlon,
lon=None,
datum=Datums.WGS84,
Osgr=Osgr,
name=NN,
**Osgr_kwds):
'''Convert a lat-/longitude point to an OSGR coordinate.
@arg latlon: Latitude (C{degrees}) or an (ellipsoidal) geodetic
C{LatLon} point.
@kwarg lon: Optional longitude in degrees (scalar or C{None}).
@kwarg datum: Optional datum to convert B{C{lat, lon}} from
(L{Datum}, L{Ellipsoid}, L{Ellipsoid2} or
L{a_f2Tuple}).
@kwarg Osgr: Optional class to return the OSGR coordinate
(L{Osgr}) or C{None}.
@kwarg name: Optional B{C{Osgr}} name (C{str}).
@kwarg Osgr_kwds: Optional, additional B{C{Osgr}} keyword
arguments, ignored if B{C{Osgr=None}}.
@return: The OSGR coordinate (B{C{Osgr}}) or an
L{EasNor2Tuple}C{(easting, northing)} if B{C{Osgr}}
is C{None}.
@raise OSGRError: Invalid B{C{latlon}} or B{C{lon}}.
@raise TypeError: Non-ellipsoidal B{C{latlon}} or invalid
B{C{datum}} or conversion failed.
@example:
>>> p = LatLon(52.65798, 1.71605)
>>> r = toOsgr(p) # TG 51409 13177
>>> # for conversion of (historical) OSGB36 lat-/longitude:
>>> r = toOsgr(52.65757, 1.71791, datum=Datums.OSGB36)
'''
if not isinstance(latlon, _LLEB):
# XXX fix failing _LLEB.convertDatum()
latlon = _LLEB(*parseDMS2(latlon, lon), datum=datum)
elif lon is not None:
raise OSGRError(lon=lon, txt='not %s' % (None, ))
elif not name: # use latlon.name
name = nameof(latlon)
# if necessary, convert to OSGB36 first
ll = _ll2datum(latlon, _Datums_OSGB36, _latlon_)
try:
a, b = ll.philam
except AttributeError:
a, b = map1(radians, ll.lat, ll.lon)
sa, ca = sincos2(a)
E = _Datums_OSGB36.ellipsoid
s = E.e2s2(sa) # r, v = E.roc2_(sa, _F0); r = v / r
v = E.a * _F0 / sqrt(s) # nu
r = s / E.e12 # nu / rho == v / (v * E.e12 / s) == s / E.e12
x2 = r - 1 # η2
ta = tan(a)
ca3, ca5 = fpowers(ca, 5, 3) # PYCHOK false!
ta2, ta4 = fpowers(ta, 4, 2) # PYCHOK false!
vsa = v * sa
I4 = (E.b * _F0 * _M(E.Mabcd, a) + _N0, (vsa / 2) * ca,
(vsa / 24) * ca3 * fsum_(5, -ta2, 9 * x2),
(vsa / 720) * ca5 * fsum_(61, ta4, -58 * ta2))
V4 = (_E0, (v * ca), (v / 6) * ca3 * (r - ta2), (v / 120) * ca5 * fdot(
(-18, 1, 14, -58), ta2, 5 + ta4, x2, ta2 * x2))
d, d2, d3, d4, d5, d6 = fpowers(b - _B0, 6) # PYCHOK false!
n = fdot(I4, 1, d2, d4, d6)
e = fdot(V4, 1, d, d3, d5)
if Osgr is None:
r = _EasNor2Tuple(e, n)
else:
r = Osgr(e, n, datum=_Datums_OSGB36, **Osgr_kwds)
if lon is None and isinstance(latlon, _LLEB):
r._latlon = latlon # XXX weakref(latlon)?
return _xnamed(r, name)
def toLatLon(self, LatLon=None, datum=Datums.WGS84):
'''Convert this OSGR coordinate to an (ellipsoidal) geodetic
point.
While OS grid references are based on the OSGB36 datum, the
I{Ordnance Survey} have deprecated the use of OSGB36 for
lat-/longitude coordinates (in favour of WGS84). Hence, this
method returns WGS84 by default with OSGB36 as an option,
U{see<https://www.OrdnanceSurvey.co.UK/blog/2014/12/2>}.
I{Note formulation implemented here due to Thomas, Redfearn,
etc. is as published by OS, but is inferior to Krüger as
used by e.g. Karney 2011.}
@kwarg LatLon: Optional ellipsoidal class to return the
geodetic point (C{LatLon}) or C{None}.
@kwarg datum: Optional datum to convert to (L{Datum},
L{Ellipsoid}, L{Ellipsoid2}, L{Ellipsoid2}
or L{a_f2Tuple}).
@return: The geodetic point (B{C{LatLon}}) or a
L{LatLonDatum3Tuple}C{(lat, lon, datum)}
if B{C{LatLon}} is C{None}.
@raise OSGRError: No convergence.
@raise TypeError: If B{C{LatLon}} is not ellipsoidal or
B{C{datum}} is invalid or conversion failed.
@example:
>>> from pygeodesy import ellipsoidalVincenty as eV
>>> g = Osgr(651409.903, 313177.270)
>>> p = g.toLatLon(eV.LatLon) # 52°39′28.723″N, 001°42′57.787″E
>>> # to obtain (historical) OSGB36 lat-/longitude point
>>> p = g.toLatLon(eV.LatLon, datum=Datums.OSGB36) # 52°39′27.253″N, 001°43′04.518″E
'''
if self._latlon:
return self._latlon3(LatLon, datum)
E = self.datum.ellipsoid # _Datums_OSGB36.ellipsoid, Airy130
a_F0 = E.a * _F0
b_F0 = E.b * _F0
e, n = self.easting, self.northing
n_N0 = n - _N0
a, m = _A0, n_N0
sa = Fsum(a)
for self._iteration in range(1, _TRIPS):
a = sa.fsum_(m / a_F0)
m = n_N0 - b_F0 * _M(E.Mabcd, a) # meridional arc
if abs(m) < _10um:
break
else:
t = _dot_(_item_ps(self.classname, self.toStr(prec=-3)),
self.toLatLon.__name__)
raise OSGRError(_no_convergence_, txt=t)
sa, ca = sincos2(a)
s = E.e2s2(sa) # r, v = E.roc2_(sa, _F0)
v = a_F0 / sqrt(s) # nu
r = v * E.e12 / s # rho = a_F0 * E.e12 / pow(s, 1.5) == a_F0 * E.e12 / (s * sqrt(s))
vr = v / r # == s / E.e12
x2 = vr - 1 # η2
ta = tan(a)
v3, v5, v7 = fpowers(v, 7, 3) # PYCHOK false!
ta2, ta4, ta6 = fpowers(ta**2, 3) # PYCHOK false!
tar = ta / r
V4 = (a, tar / (2 * v), tar / (24 * v3) * fdot(
(1, 3, -9), 5 + x2, ta2, ta2 * x2), tar / (720 * v5) * fdot(
(61, 90, 45), 1, ta2, ta4))
csa = 1.0 / ca
X5 = (_B0, csa / v, csa / (6 * v3) * fsum_(vr, ta2, ta2),
csa / (120 * v5) * fdot(
(5, 28, 24), 1, ta2, ta4), csa / (5040 * v7) * fdot(
(61, 662, 1320, 720), 1, ta2, ta4, ta6))
d, d2, d3, d4, d5, d6, d7 = fpowers(e - _E0, 7) # PYCHOK false!
a = fdot(V4, 1, -d2, d4, -d6)
b = fdot(X5, 1, d, -d3, d5, -d7)
r = _LLEB(degrees90(a),
degrees180(b),
datum=self.datum,
name=self.name)
r._iteration = self._iteration # only ellipsoidal LatLon
self._latlon = r
return self._latlon3(LatLon, datum)
def reverse(self, x, y, lon0=0, name=NN, LatLon=None, **LatLon_kwds):
'''Convert an east- and northing location to geodetic lat- and longitude.
@arg x: Easting of the location (C{meter}).
@arg y: Northing of the location (C{meter}).
@kwarg lon0: Optional central meridian longitude (C{degrees}).
@kwarg name: Optional name for the location (C{str}).
@kwarg LatLon: Class to use (C{LatLon}) or C{None}.
@kwarg LatLon_kwds: Optional, additional B{C{LatLon}} keyword
arguments, ignored if C{B{LatLon}=None}.
@return: The geodetic (C{LatLon}) or if B{C{LatLon}} is C{None} an
L{Albers7Tuple}C{(x, y, lat, lon, gamma, scale, datum)}.
@note: The origin latitude is returned by C{property lat0}. No
false easting or northing is added. The returned value of
C{lon} is in the range C{[-180..180] degrees} and C{lat}
is in the range C{[-90..90] degrees}. If the given
B{C{x}} or B{C{y}} point is outside the valid projected
space the nearest pole is returned.
'''
x = Meter(x=x)
y = Meter(y=y)
k0 = self._k0
n0 = self._n0
k0n0 = self._k0n0
nrho0 = self._nrho0
txi0 = self._txi0
y_ = self._sign * y
nx = k0n0 * x
ny = k0n0 * y_
y1 = nrho0 - ny
drho = den = nrho0 + hypot(nx,
y1) # 0 implies origin with polar aspect
if den:
drho = fsum_(x * nx, -_2_0 * y_ * nrho0, y_ * ny) * k0 / den
# dsxia = scxi0 * dsxi
dsxia = -self._scxi0 * (_2_0 * nrho0 + n0 * drho) * drho / self._qZa2
t = _1_0 - dsxia * (_2_0 * txi0 + dsxia)
txi = (txi0 + dsxia) / (sqrt(t) if t > _EPS__4 else _EPS__2)
ta = self._tanf(txi)
lat = atand(ta * self._sign)
th = atan2(nx, y1)
lon = degrees(th / self._k02n0 if n0 else x / (y1 * k0))
if lon0:
lon += _norm180(lon0)
lon = _norm180(lon)
if LatLon is None:
g = degrees360(self._sign * th)
if den:
k0 = self._azik(nrho0 + n0 * drho, ta)
r = Albers7Tuple(x, y, lat, lon, g, k0, self.datum)
else:
kwds = _xkwds(LatLon_kwds, datum=self.datum)
r = LatLon(lat, lon, **kwds)
return self._xnamed(r, name=name)
