def __init__(self, a, f):
"""
Construct a Geodesic object for ellipsoid with major radius a and
flattening f.
"""
self._a = float(a)
self._f = float(f) if f <= 1 else 1.0 / f
self._f1 = 1 - self._f
self._e2 = self._f * (2 - self._f)
self._ep2 = self._e2 / Math.sq(self._f1) # e2 / (1 - e2)
self._n = self._f / (2 - self._f)
self._b = self._a * self._f1
# authalic radius squared
self._c2 = (
Math.sq(self._a) + Math.sq(self._b) *
(1 if self._e2 == 0 else
(Math.atanh(math.sqrt(self._e2)) if self._e2 > 0 else math.atan(
math.sqrt(-self._e2))) / math.sqrt(abs(self._e2)))) / 2
# The sig12 threshold for "really short"
self._etol2 = 0.01 * Geodesic.tol2_ / max(0.1, math.sqrt(abs(
self._e2)))
if not (Math.isfinite(self._a) and self._a > 0):
raise ValueError("Major radius is not positive")
if not (Math.isfinite(self._b) and self._b > 0):
raise ValueError("Minor radius is not positive")
self._A3x = range(Geodesic.nA3x_)
self._C3x = range(Geodesic.nC3x_)
self._C4x = range(Geodesic.nC4x_)
self.A3coeff()
self.C3coeff()
self.C4coeff()
def __init__(self, a, f):
"""
Construct a Geodesic object for ellipsoid with major radius a and
flattening f.
"""
self._a = float(a)
self._f = float(f) if f <= 1 else 1.0/f
self._f1 = 1 - self._f
self._e2 = self._f * (2 - self._f)
self._ep2 = self._e2 / Math.sq(self._f1) # e2 / (1 - e2)
self._n = self._f / ( 2 - self._f)
self._b = self._a * self._f1
# authalic radius squared
self._c2 = (Math.sq(self._a) + Math.sq(self._b) *
(1 if self._e2 == 0 else
(Math.atanh(math.sqrt(self._e2)) if self._e2 > 0 else
math.atan(math.sqrt(-self._e2))) /
math.sqrt(abs(self._e2))))/2
# The sig12 threshold for "really short"
self._etol2 = 0.01 * Geodesic.tol2_ / max(0.1, math.sqrt(abs(self._e2)))
if not(Math.isfinite(self._a) and self._a > 0):
raise ValueError("Major radius is not positive")
if not(Math.isfinite(self._b) and self._b > 0):
raise ValueError("Minor radius is not positive")
self._A3x = range(Geodesic.nA3x_)
self._C3x = range(Geodesic.nC3x_)
self._C4x = range(Geodesic.nC4x_)
self.A3coeff()
self.C3coeff()
self.C4coeff()
def __init__(self, a, f):
"""Construct a Geodesic object
:param a: the equatorial radius of the ellipsoid in meters
:param f: the flattening of the ellipsoid
An exception is thrown if *a* or the polar semi-axis *b* = *a* (1 -
*f*) is not a finite positive quantity.
"""
self.a = float(a)
"""The equatorial radius in meters (readonly)"""
self.f = float(f)
"""The flattening (readonly)"""
self._f1 = 1 - self.f
self._e2 = self.f * (2 - self.f)
self._ep2 = self._e2 / Math.sq(self._f1) # e2 / (1 - e2)
self._n = self.f / ( 2 - self.f)
self._b = self.a * self._f1
# authalic radius squared
self._c2 = (Math.sq(self.a) + Math.sq(self._b) *
(1 if self._e2 == 0 else
(Math.atanh(math.sqrt(self._e2)) if self._e2 > 0 else
math.atan(math.sqrt(-self._e2))) /
math.sqrt(abs(self._e2))))/2
# The sig12 threshold for "really short". Using the auxiliary sphere
# solution with dnm computed at (bet1 + bet2) / 2, the relative error in
# the azimuth consistency check is sig12^2 * abs(f) * min(1, 1-f/2) / 2.
# (Error measured for 1/100 < b/a < 100 and abs(f) >= 1/1000. For a given
# f and sig12, the max error occurs for lines near the pole. If the old
# rule for computing dnm = (dn1 + dn2)/2 is used, then the error increases
# by a factor of 2.) Setting this equal to epsilon gives sig12 = etol2.
# Here 0.1 is a safety factor (error decreased by 100) and max(0.001,
# abs(f)) stops etol2 getting too large in the nearly spherical case.
self._etol2 = 0.1 * Geodesic.tol2_ / math.sqrt( max(0.001, abs(self.f)) *
min(1.0, 1-self.f/2) / 2 )
if not(Math.isfinite(self.a) and self.a > 0):
raise ValueError("Equatorial radius is not positive")
if not(Math.isfinite(self._b) and self._b > 0):
raise ValueError("Polar semi-axis is not positive")
self._A3x = list(range(Geodesic.nA3x_))
self._C3x = list(range(Geodesic.nC3x_))
self._C4x = list(range(Geodesic.nC4x_))
self._A3coeff()
self._C3coeff()
self._C4coeff()
def __init__(self, a, f):
"""
Construct a Geodesic object for ellipsoid with major radius a and
flattening f.
"""
self._a = float(a)
self._f = float(f) if f <= 1 else 1.0 / f
self._f1 = 1 - self._f
self._e2 = self._f * (2 - self._f)
self._ep2 = self._e2 / Math.sq(self._f1) # e2 / (1 - e2)
self._n = self._f / (2 - self._f)
self._b = self._a * self._f1
# authalic radius squared
self._c2 = (
Math.sq(self._a) + Math.sq(self._b) *
(1 if self._e2 == 0 else
(Math.atanh(math.sqrt(self._e2)) if self._e2 > 0 else math.atan(
math.sqrt(-self._e2))) / math.sqrt(abs(self._e2)))) / 2
# The sig12 threshold for "really short". Using the auxiliary sphere
# solution with dnm computed at (bet1 + bet2) / 2, the relative error in
# the azimuth consistency check is sig12^2 * abs(f) * min(1, 1-f/2) / 2.
# (Error measured for 1/100 < b/a < 100 and abs(f) >= 1/1000. For a given
# f and sig12, the max error occurs for lines near the pole. If the old
# rule for computing dnm = (dn1 + dn2)/2 is used, then the error increases
# by a factor of 2.) Setting this equal to epsilon gives sig12 = etol2.
# Here 0.1 is a safety factor (error decreased by 100) and max(0.001,
# abs(f)) stops etol2 getting too large in the nearly spherical case.
self._etol2 = 0.1 * Geodesic.tol2_ / math.sqrt(
max(0.001, abs(self._f)) * min(1.0, 1 - self._f / 2) / 2)
if not (Math.isfinite(self._a) and self._a > 0):
raise ValueError("Major radius is not positive")
if not (Math.isfinite(self._b) and self._b > 0):
raise ValueError("Minor radius is not positive")
self._A3x = list(range(Geodesic.nA3x_))
self._C3x = list(range(Geodesic.nC3x_))
self._C4x = list(range(Geodesic.nC4x_))
self.A3coeff()
self.C3coeff()
self.C4coeff()
def __init__(self, a, f):
"""Construct a Geodesic object for ellipsoid with major radius a and
flattening f.
"""
self._a = float(a)
self._f = float(f) if f <= 1 else 1.0/f
self._f1 = 1 - self._f
self._e2 = self._f * (2 - self._f)
self._ep2 = self._e2 / Math.sq(self._f1) # e2 / (1 - e2)
self._n = self._f / ( 2 - self._f)
self._b = self._a * self._f1
# authalic radius squared
self._c2 = (Math.sq(self._a) + Math.sq(self._b) *
(1 if self._e2 == 0 else
(Math.atanh(math.sqrt(self._e2)) if self._e2 > 0 else
math.atan(math.sqrt(-self._e2))) /
math.sqrt(abs(self._e2))))/2
# The sig12 threshold for "really short". Using the auxiliary sphere
# solution with dnm computed at (bet1 + bet2) / 2, the relative error in
# the azimuth consistency check is sig12^2 * abs(f) * min(1, 1-f/2) / 2.
# (Error measured for 1/100 < b/a < 100 and abs(f) >= 1/1000. For a given
# f and sig12, the max error occurs for lines near the pole. If the old
# rule for computing dnm = (dn1 + dn2)/2 is used, then the error increases
# by a factor of 2.) Setting this equal to epsilon gives sig12 = etol2.
# Here 0.1 is a safety factor (error decreased by 100) and max(0.001,
# abs(f)) stops etol2 getting too large in the nearly spherical case.
self._etol2 = 0.1 * Geodesic.tol2_ / math.sqrt( max(0.001, abs(self._f)) *
min(1.0, 1-self._f/2) / 2 )
if not(Math.isfinite(self._a) and self._a > 0):
raise ValueError("Major radius is not positive")
if not(Math.isfinite(self._b) and self._b > 0):
raise ValueError("Minor radius is not positive")
self._A3x = list(range(Geodesic.nA3x_))
self._C3x = list(range(Geodesic.nC3x_))
self._C4x = list(range(Geodesic.nC4x_))
self.A3coeff()
self.C3coeff()
self.C4coeff()
def CheckDistance(s):
"""Check that s is a legal distance"""
if not (Math.isfinite(s)):
raise ValueError("distance " + str(s) + " not a finite number")
def CheckDistance(s):
"""Check that s is a legal distance"""
if not (Math.isfinite(s)):
raise ValueError("distance " + str(s) + " not a finite number")
def CheckDistance(s):
if not (Math.isfinite(s)):
raise ValueError("distance " + str(s) + " not a finite number")
def _GenPosition(self, arcmode, s12_a12, outmask):
"""Private: General solution of position along geodesic"""
from geographiclib.geodesic import Geodesic
a12 = lat2 = lon2 = azi2 = s12 = m12 = M12 = M21 = S12 = Math.nan
outmask &= self.caps & Geodesic.OUT_MASK
if not (arcmode or
(self.caps & (Geodesic.OUT_MASK & Geodesic.DISTANCE_IN))):
# Uninitialized or impossible distance calculation requested
return a12, lat2, lon2, azi2, s12, m12, M12, M21, S12
# Avoid warning about uninitialized B12.
B12 = 0.0; AB1 = 0.0
if arcmode:
# Interpret s12_a12 as spherical arc length
sig12 = math.radians(s12_a12)
ssig12, csig12 = Math.sincosd(s12_a12)
else:
# Interpret s12_a12 as distance
tau12 = s12_a12 / (self._b * (1 + self._A1m1))
tau12 = tau12 if Math.isfinite(tau12) else Math.nan
s = math.sin(tau12); c = math.cos(tau12)
# tau2 = tau1 + tau12
B12 = - Geodesic._SinCosSeries(True,
self._stau1 * c + self._ctau1 * s,
self._ctau1 * c - self._stau1 * s,
self._C1pa)
sig12 = tau12 - (B12 - self._B11)
ssig12 = math.sin(sig12); csig12 = math.cos(sig12)
if abs(self.f) > 0.01:
# Reverted distance series is inaccurate for |f| > 1/100, so correct
# sig12 with 1 Newton iteration. The following table shows the
# approximate maximum error for a = WGS_a() and various f relative to
# GeodesicExact.
# erri = the error in the inverse solution (nm)
# errd = the error in the direct solution (series only) (nm)
# errda = the error in the direct solution (series + 1 Newton) (nm)
#
# f erri errd errda
# -1/5 12e6 1.2e9 69e6
# -1/10 123e3 12e6 765e3
# -1/20 1110 108e3 7155
# -1/50 18.63 200.9 27.12
# -1/100 18.63 23.78 23.37
# -1/150 18.63 21.05 20.26
# 1/150 22.35 24.73 25.83
# 1/100 22.35 25.03 25.31
# 1/50 29.80 231.9 30.44
# 1/20 5376 146e3 10e3
# 1/10 829e3 22e6 1.5e6
# 1/5 157e6 3.8e9 280e6
ssig2 = self._ssig1 * csig12 + self._csig1 * ssig12
csig2 = self._csig1 * csig12 - self._ssig1 * ssig12
B12 = Geodesic._SinCosSeries(True, ssig2, csig2, self._C1a)
serr = ((1 + self._A1m1) * (sig12 + (B12 - self._B11)) -
s12_a12 / self._b)
sig12 = sig12 - serr / math.sqrt(1 + self._k2 * Math.sq(ssig2))
ssig12 = math.sin(sig12); csig12 = math.cos(sig12)
# Update B12 below
# real omg12, lam12, lon12
# real ssig2, csig2, sbet2, cbet2, somg2, comg2, salp2, calp2
# sig2 = sig1 + sig12
ssig2 = self._ssig1 * csig12 + self._csig1 * ssig12
csig2 = self._csig1 * csig12 - self._ssig1 * ssig12
dn2 = math.sqrt(1 + self._k2 * Math.sq(ssig2))
if outmask & (
Geodesic.DISTANCE | Geodesic.REDUCEDLENGTH | Geodesic.GEODESICSCALE):
if arcmode or abs(self.f) > 0.01:
B12 = Geodesic._SinCosSeries(True, ssig2, csig2, self._C1a)
AB1 = (1 + self._A1m1) * (B12 - self._B11)
# sin(bet2) = cos(alp0) * sin(sig2)
sbet2 = self._calp0 * ssig2
# Alt: cbet2 = hypot(csig2, salp0 * ssig2)
cbet2 = math.hypot(self._salp0, self._calp0 * csig2)
if cbet2 == 0:
# I.e., salp0 = 0, csig2 = 0. Break the degeneracy in this case
cbet2 = csig2 = Geodesic.tiny_
# tan(alp0) = cos(sig2)*tan(alp2)
salp2 = self._salp0; calp2 = self._calp0 * csig2 # No need to normalize
if outmask & Geodesic.DISTANCE:
s12 = self._b * ((1 + self._A1m1) * sig12 + AB1) if arcmode else s12_a12
if outmask & Geodesic.LONGITUDE:
# tan(omg2) = sin(alp0) * tan(sig2)
somg2 = self._salp0 * ssig2; comg2 = csig2 # No need to normalize
E = Math.copysign(1, self._salp0) # East or west going?
# omg12 = omg2 - omg1
omg12 = (E * (sig12
- (math.atan2( ssig2, csig2) -
math.atan2( self._ssig1, self._csig1))
+ (math.atan2(E * somg2, comg2) -
math.atan2(E * self._somg1, self._comg1)))
if outmask & Geodesic.LONG_UNROLL
else math.atan2(somg2 * self._comg1 - comg2 * self._somg1,
comg2 * self._comg1 + somg2 * self._somg1))
lam12 = omg12 + self._A3c * (
sig12 + (Geodesic._SinCosSeries(True, ssig2, csig2, self._C3a)
- self._B31))
lon12 = math.degrees(lam12)
lon2 = (self.lon1 + lon12 if outmask & Geodesic.LONG_UNROLL else
Math.AngNormalize(Math.AngNormalize(self.lon1) +
Math.AngNormalize(lon12)))
if outmask & Geodesic.LATITUDE:
lat2 = Math.atan2d(sbet2, self._f1 * cbet2)
if outmask & Geodesic.AZIMUTH:
azi2 = Math.atan2d(salp2, calp2)
if outmask & (Geodesic.REDUCEDLENGTH | Geodesic.GEODESICSCALE):
B22 = Geodesic._SinCosSeries(True, ssig2, csig2, self._C2a)
AB2 = (1 + self._A2m1) * (B22 - self._B21)
J12 = (self._A1m1 - self._A2m1) * sig12 + (AB1 - AB2)
if outmask & Geodesic.REDUCEDLENGTH:
# Add parens around (_csig1 * ssig2) and (_ssig1 * csig2) to ensure
# accurate cancellation in the case of coincident points.
m12 = self._b * (( dn2 * (self._csig1 * ssig2) -
self._dn1 * (self._ssig1 * csig2))
- self._csig1 * csig2 * J12)
if outmask & Geodesic.GEODESICSCALE:
t = (self._k2 * (ssig2 - self._ssig1) *
(ssig2 + self._ssig1) / (self._dn1 + dn2))
M12 = csig12 + (t * ssig2 - csig2 * J12) * self._ssig1 / self._dn1
M21 = csig12 - (t * self._ssig1 - self._csig1 * J12) * ssig2 / dn2
if outmask & Geodesic.AREA:
B42 = Geodesic._SinCosSeries(False, ssig2, csig2, self._C4a)
# real salp12, calp12
if self._calp0 == 0 or self._salp0 == 0:
# alp12 = alp2 - alp1, used in atan2 so no need to normalize
salp12 = salp2 * self.calp1 - calp2 * self.salp1
calp12 = calp2 * self.calp1 + salp2 * self.salp1
else:
# tan(alp) = tan(alp0) * sec(sig)
# tan(alp2-alp1) = (tan(alp2) -tan(alp1)) / (tan(alp2)*tan(alp1)+1)
# = calp0 * salp0 * (csig1-csig2) / (salp0^2 + calp0^2 * csig1*csig2)
# If csig12 > 0, write
# csig1 - csig2 = ssig12 * (csig1 * ssig12 / (1 + csig12) + ssig1)
# else
# csig1 - csig2 = csig1 * (1 - csig12) + ssig12 * ssig1
# No need to normalize
salp12 = self._calp0 * self._salp0 * (
self._csig1 * (1 - csig12) + ssig12 * self._ssig1 if csig12 <= 0
else ssig12 * (self._csig1 * ssig12 / (1 + csig12) + self._ssig1))
calp12 = (Math.sq(self._salp0) +
Math.sq(self._calp0) * self._csig1 * csig2)
S12 = (self._c2 * math.atan2(salp12, calp12) +
self._A4 * (B42 - self._B41))
a12 = s12_a12 if arcmode else math.degrees(sig12)
return a12, lat2, lon2, azi2, s12, m12, M12, M21, S12
def CheckDistance(s):
if not (Math.isfinite(s)):
raise ValueError("distance " + str(s) + " not a finite number")
