Coverage for pygeodesy/formy.py: 98%
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2# -*- coding: utf-8 -*-
4u'''Formulary of basic geodesy functions and approximations.
5'''
6# make sure int/int division yields float quotient, see .basics
7from __future__ import division as _; del _ # PYCHOK semicolon
9# from pygeodesy.cartesianBase import CartesianBase # _MODS
10from pygeodesy.constants import EPS, EPS0, EPS1, PI, PI2, PI3, PI_2, R_M, \
11 _0_0s, float0_, isnon0, remainder, _umod_PI2, \
12 _0_0, _0_125, _0_25, _0_5, _1_0, _2_0, _4_0, \
13 _32_0, _90_0, _180_0, _360_0
14from pygeodesy.datums import Datum, Ellipsoid, _ellipsoidal_datum, \
15 _mean_radius, _spherical_datum, _WGS84, _EWGS84
16# from pygeodesy.ellipsoids import Ellipsoid, _EWGS84 # from .datums
17from pygeodesy.errors import IntersectionError, LimitError, limiterrors, \
18 _TypeError, _ValueError, _xattr, _xError, \
19 _xcallable,_xkwds, _xkwds_pop2
20from pygeodesy.fmath import euclid, hypot, hypot2, sqrt0
21from pygeodesy.fsums import fsumf_, Fmt, unstr
22# from pygeodesy.internals import _dunder_nameof # from .named
23from pygeodesy.interns import _delta_, _distant_, _inside_, _SPACE_, _too_
24from pygeodesy.lazily import _ALL_LAZY, _ALL_MODS as _MODS
25from pygeodesy.named import _name__, _name2__, _NamedTuple, _xnamed, \
26 _dunder_nameof
27from pygeodesy.namedTuples import Bearing2Tuple, Distance4Tuple, LatLon2Tuple, \
28 Intersection3Tuple, PhiLam2Tuple, Vector3Tuple
29# from pygeodesy.streprs import Fmt, unstr # from .fsums
30# from pygeodesy.triaxials import _hartzell3 # _MODS
31from pygeodesy.units import _isHeight, _isRadius, Bearing, Degrees_, Distance, \
32 Distance_, Height, Lamd, Lat, Lon, Meter_, Phid, \
33 Radians, Radians_, Radius, Radius_, Scalar, _100km
34from pygeodesy.utily import acos1, atan2b, atan2d, degrees2m, _loneg, m2degrees, \
35 tan_2, sincos2, sincos2_, sincos2d_, _Wrap
36# from pygeodesy.vector3d import _otherV3d # _MODS
37# from pygeodesy.vector3dBase import _xyz_y_z3 # _MODS
38# from pygeodesy import ellipsoidalExact, ellipsoidalKarney, vector3d, \
39# sphericalNvector, sphericalTrigonometry # _MODS
41from contextlib import contextmanager
42from math import asin, atan, atan2, cos, degrees, fabs, radians, sin, sqrt # pow
44__all__ = _ALL_LAZY.formy
45__version__ = '24.07.29'
47_RADIANS2 = (PI / _180_0)**2 # degrees- to radians-squared
48_ratio_ = 'ratio'
49_xline_ = 'xline'
52def _anti2(a, b, n_2, n, n2):
53 '''(INTERNAL) Helper for C{antipode} and C{antipode_}.
54 '''
55 r = remainder(a, n) if fabs(a) > n_2 else a
56 if r == a:
57 r = -r
58 b += n
59 if fabs(b) > n:
60 b = remainder(b, n2)
61 return float0_(r, b)
64def antipode(lat, lon, **name):
65 '''Return the antipode, the point diametrically opposite to a given
66 point in C{degrees}.
68 @arg lat: Latitude (C{degrees}).
69 @arg lon: Longitude (C{degrees}).
70 @kwarg name: Optional C{B{name}=NN} (C{str}).
72 @return: A L{LatLon2Tuple}C{(lat, lon)}.
74 @see: Functions L{antipode_} and L{normal} and U{Geosphere
75 <https://CRAN.R-Project.org/web/packages/geosphere/geosphere.pdf>}.
76 '''
77 return LatLon2Tuple(*_anti2(lat, lon, _90_0, _180_0, _360_0), **name)
80def antipode_(phi, lam, **name):
81 '''Return the antipode, the point diametrically opposite to a given
82 point in C{radians}.
84 @arg phi: Latitude (C{radians}).
85 @arg lam: Longitude (C{radians}).
86 @kwarg name: Optional C{B{name}=NN} (C{str}).
88 @return: A L{PhiLam2Tuple}C{(phi, lam)}.
90 @see: Functions L{antipode} and L{normal_} and U{Geosphere
91 <https://CRAN.R-Project.org/web/packages/geosphere/geosphere.pdf>}.
92 '''
93 return PhiLam2Tuple(*_anti2(phi, lam, PI_2, PI, PI2), **name)
96def bearing(lat1, lon1, lat2, lon2, **final_wrap):
97 '''Compute the initial or final bearing (forward or reverse azimuth)
98 between two (spherical) points.
100 @arg lat1: Start latitude (C{degrees}).
101 @arg lon1: Start longitude (C{degrees}).
102 @arg lat2: End latitude (C{degrees}).
103 @arg lon2: End longitude (C{degrees}).
104 @kwarg final_wrap: Optional keyword arguments for function
105 L{pygeodesy.bearing_}.
107 @return: Initial or final bearing (compass C{degrees360}) or zero if
108 both points coincide.
109 '''
110 r = bearing_(Phid(lat1=lat1), Lamd(lon1=lon1),
111 Phid(lat2=lat2), Lamd(lon2=lon2), **final_wrap)
112 return degrees(r)
115def bearing_(phi1, lam1, phi2, lam2, final=False, wrap=False):
116 '''Compute the initial or final bearing (forward or reverse azimuth) between
117 two (spherical) points.
119 @arg phi1: Start latitude (C{radians}).
120 @arg lam1: Start longitude (C{radians}).
121 @arg phi2: End latitude (C{radians}).
122 @arg lam2: End longitude (C{radians}).
123 @kwarg final: If C{True}, return the final, otherwise the initial bearing
124 (C{bool}).
125 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll B{C{phi2}} and
126 B{C{lam2}} (C{bool}).
128 @return: Initial or final bearing (compass C{radiansPI2}) or zero if both
129 are coincident.
131 @see: U{Bearing<https://www.Movable-Type.co.UK/scripts/latlong.html>}, U{Course
132 between two points<https://www.EdWilliams.org/avform147.htm#Crs>} and
133 U{Bearing Between Two Points<https://web.Archive.org/web/20020630205931/
134 https://MathForum.org/library/drmath/view/55417.html>}.
135 '''
136 db, phi2, lam2 = _Wrap.philam3(lam1, phi2, lam2, wrap)
137 if final: # swap plus PI
138 phi1, lam1, phi2, lam2, db = phi2, lam2, phi1, lam1, -db
139 r = PI3
140 else:
141 r = PI2
142 sa1, ca1, sa2, ca2, sdb, cdb = sincos2_(phi1, phi2, db)
144 x = ca1 * sa2 - sa1 * ca2 * cdb
145 y = sdb * ca2
146 return _umod_PI2(atan2(y, x) + r) # .utily.wrapPI2
149def _bearingTo2(p1, p2, wrap=False): # for points.ispolar, sphericalTrigonometry.areaOf
150 '''(INTERNAL) Compute initial and final bearing.
151 '''
152 try: # for LatLon_ and ellipsoidal LatLon
153 return p1.bearingTo2(p2, wrap=wrap)
154 except AttributeError:
155 pass
156 # XXX spherical version, OK for ellipsoidal ispolar?
157 t = p1.philam + p2.philam
158 return Bearing2Tuple(degrees(bearing_(*t, final=False, wrap=wrap)),
159 degrees(bearing_(*t, final=True, wrap=wrap)),
160 name__=_bearingTo2)
163def compassAngle(lat1, lon1, lat2, lon2, adjust=True, wrap=False):
164 '''Return the angle from North for the direction vector M{(lon2 - lon1,
165 lat2 - lat1)} between two points.
167 Suitable only for short, not near-polar vectors up to a few hundred
168 Km or Miles. Use function L{pygeodesy.bearing} for longer vectors.
170 @arg lat1: From latitude (C{degrees}).
171 @arg lon1: From longitude (C{degrees}).
172 @arg lat2: To latitude (C{degrees}).
173 @arg lon2: To longitude (C{degrees}).
174 @kwarg adjust: Adjust the longitudinal delta by the cosine of the
175 mean latitude (C{bool}).
176 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll B{C{lat2}}
177 and B{C{lon2}} (C{bool}).
179 @return: Compass angle from North (C{degrees360}).
181 @note: Courtesy of Martin Schultz.
183 @see: U{Local, flat earth approximation
184 <https://www.EdWilliams.org/avform.htm#flat>}.
185 '''
186 d_lon, lat2, lon2 = _Wrap.latlon3(lon1, lat2, lon2, wrap)
187 if adjust: # scale delta lon
188 d_lon *= _scale_deg(lat1, lat2)
189 return atan2b(d_lon, lat2 - lat1)
192def cosineAndoyerLambert(lat1, lon1, lat2, lon2, datum=_WGS84, wrap=False):
193 '''Compute the distance between two (ellipsoidal) points using the U{Andoyer-Lambert
194 <https://books.google.com/books?id=x2UiAQAAIAAJ>} correction of the U{Law of
195 Cosines<https://www.Movable-Type.co.UK/scripts/latlong.html#cosine-law>} formula.
197 @arg lat1: Start latitude (C{degrees}).
198 @arg lon1: Start longitude (C{degrees}).
199 @arg lat2: End latitude (C{degrees}).
200 @arg lon2: End longitude (C{degrees}).
201 @kwarg datum: Datum (L{Datum}) or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
202 L{a_f2Tuple}) to use.
203 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll B{C{lat2}} and
204 B{C{lon2}} (C{bool}).
206 @return: Distance (C{meter}, same units as the B{C{datum}}'s ellipsoid axes or
207 C{radians} if C{B{datum} is None}).
209 @raise TypeError: Invalid B{C{datum}}.
211 @see: Functions L{cosineAndoyerLambert_}, L{cosineForsytheAndoyerLambert},
212 L{cosineLaw}, L{equirectangular}, L{euclidean}, L{flatLocal}/L{hubeny},
213 L{flatPolar}, L{haversine}, L{thomas} and L{vincentys} and method
214 L{Ellipsoid.distance2}.
215 '''
216 return _dE(cosineAndoyerLambert_, datum, wrap, lat1, lon1, lat2, lon2)
219def cosineAndoyerLambert_(phi2, phi1, lam21, datum=_WGS84):
220 '''Compute the I{angular} distance between two (ellipsoidal) points using the U{Andoyer-Lambert
221 <https://books.google.com/books?id=x2UiAQAAIAAJ>} correction of the U{Law of
222 Cosines<https://www.Movable-Type.co.UK/scripts/latlong.html#cosine-law>} formula.
224 @arg phi2: End latitude (C{radians}).
225 @arg phi1: Start latitude (C{radians}).
226 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
227 @kwarg datum: Datum (L{Datum}) or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
228 L{a_f2Tuple}) to use.
230 @return: Angular distance (C{radians}).
232 @raise TypeError: Invalid B{C{datum}}.
234 @see: Functions L{cosineAndoyerLambert}, L{cosineForsytheAndoyerLambert_},
235 L{cosineLaw_}, L{euclidean_}, L{flatLocal_}/L{hubeny_}, L{flatPolar_},
236 L{haversine_}, L{thomas_} and L{vincentys_} and U{Geodesy-PHP
237 <https://GitHub.com/jtejido/geodesy-php/blob/master/src/Geodesy/Distance/
238 AndoyerLambert.php>}.
239 '''
240 s2, c2, s1, c1, r, c21 = _sincosa6(phi2, phi1, lam21)
241 if isnon0(c1) and isnon0(c2):
242 E = _ellipsoidal(datum, cosineAndoyerLambert_)
243 if E.f: # ellipsoidal
244 r2 = atan2(E.b_a * s2, c2)
245 r1 = atan2(E.b_a * s1, c1)
246 s2, c2, s1, c1 = sincos2_(r2, r1)
247 r = acos1(s1 * s2 + c1 * c2 * c21)
248 if r:
249 sr, _, sr_2, cr_2 = sincos2_(r, r * _0_5)
250 if isnon0(sr_2) and isnon0(cr_2):
251 s = (sr + r) * ((s1 - s2) / sr_2)**2
252 c = (sr - r) * ((s1 + s2) / cr_2)**2
253 r += (c - s) * E.f * _0_125
254 return r
257def cosineForsytheAndoyerLambert(lat1, lon1, lat2, lon2, datum=_WGS84, wrap=False):
258 '''Compute the distance between two (ellipsoidal) points using the U{Forsythe-Andoyer-Lambert
259 <https://www2.UNB.Ca/gge/Pubs/TR77.pdf>} correction of the U{Law of Cosines
260 <https://www.Movable-Type.co.UK/scripts/latlong.html#cosine-law>} formula.
262 @arg lat1: Start latitude (C{degrees}).
263 @arg lon1: Start longitude (C{degrees}).
264 @arg lat2: End latitude (C{degrees}).
265 @arg lon2: End longitude (C{degrees}).
266 @kwarg datum: Datum (L{Datum}) or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
267 L{a_f2Tuple}) to use.
268 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll B{C{lat2}} and
269 B{C{lon2}} (C{bool}).
271 @return: Distance (C{meter}, same units as the B{C{datum}}'s ellipsoid axes or
272 C{radians} if C{B{datum} is None}).
274 @raise TypeError: Invalid B{C{datum}}.
276 @see: Functions L{cosineForsytheAndoyerLambert_}, L{cosineAndoyerLambert},
277 L{cosineLaw}, L{equirectangular}, L{euclidean}, L{flatLocal}/L{hubeny},
278 L{flatPolar}, L{haversine}, L{thomas} and L{vincentys} and method
279 L{Ellipsoid.distance2}.
280 '''
281 return _dE(cosineForsytheAndoyerLambert_, datum, wrap, lat1, lon1, lat2, lon2)
284def cosineForsytheAndoyerLambert_(phi2, phi1, lam21, datum=_WGS84):
285 '''Compute the I{angular} distance between two (ellipsoidal) points using the
286 U{Forsythe-Andoyer-Lambert<https://www2.UNB.Ca/gge/Pubs/TR77.pdf>} correction of
287 the U{Law of Cosines<https://www.Movable-Type.co.UK/scripts/latlong.html#cosine-law>}
288 formula.
290 @arg phi2: End latitude (C{radians}).
291 @arg phi1: Start latitude (C{radians}).
292 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
293 @kwarg datum: Datum (L{Datum}) or ellipsoid to use (L{Ellipsoid},
294 L{Ellipsoid2} or L{a_f2Tuple}).
296 @return: Angular distance (C{radians}).
298 @raise TypeError: Invalid B{C{datum}}.
300 @see: Functions L{cosineForsytheAndoyerLambert}, L{cosineAndoyerLambert_},
301 L{cosineLaw_}, L{euclidean_}, L{flatLocal_}/L{hubeny_}, L{flatPolar_},
302 L{haversine_}, L{thomas_} and L{vincentys_} and U{Geodesy-PHP
303 <https://GitHub.com/jtejido/geodesy-php/blob/master/src/Geodesy/
304 Distance/ForsytheCorrection.php>}.
305 '''
306 s2, c2, s1, c1, r, _ = _sincosa6(phi2, phi1, lam21)
307 if r and isnon0(c1) and isnon0(c2):
308 E = _ellipsoidal(datum, cosineForsytheAndoyerLambert_)
309 if E.f: # ellipsoidal
310 sr, cr, s2r, _ = sincos2_(r, r * 2)
311 if isnon0(sr) and fabs(cr) < EPS1:
312 s = (s1 + s2)**2 / (1 + cr)
313 t = (s1 - s2)**2 / (1 - cr)
314 x = s + t
315 y = s - t
317 s = 8 * r**2 / sr
318 a = 64 * r + s * cr * 2 # 16 * r**2 / tan(r)
319 d = 48 * sr + s # 8 * r**2 / tan(r)
320 b = -2 * d
321 e = 30 * s2r
322 c = fsumf_(30 * r, e * _0_5, s * cr) # 8 * r**2 / tan(r)
323 t = fsumf_( a * x, e * y**2, b * y, -c * x**2, d * x * y)
325 r += fsumf_(-r * x, 3 * y * sr, t * E.f / _32_0) * E.f * _0_25
326 return r
329def cosineLaw(lat1, lon1, lat2, lon2, radius=R_M, wrap=False):
330 '''Compute the distance between two points using the U{spherical Law of Cosines
331 <https://www.Movable-Type.co.UK/scripts/latlong.html#cosine-law>} formula.
333 @arg lat1: Start latitude (C{degrees}).
334 @arg lon1: Start longitude (C{degrees}).
335 @arg lat2: End latitude (C{degrees}).
336 @arg lon2: End longitude (C{degrees}).
337 @kwarg radius: Mean earth radius (C{meter}), datum (L{Datum})
338 or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
339 L{a_f2Tuple}) to use.
340 @kwarg wrap: If C{True}, wrap or I{normalize} and B{C{lat2}}
341 and B{C{lon2}} (C{bool}).
343 @return: Distance (C{meter}, same units as B{C{radius}} or the
344 ellipsoid or datum axes).
346 @raise TypeError: Invalid B{C{radius}}.
348 @see: Functions L{cosineLaw_}, L{cosineAndoyerLambert},
349 L{cosineForsytheAndoyerLambert}, L{equirectangular}, L{euclidean},
350 L{flatLocal}/L{hubeny}, L{flatPolar}, L{haversine}, L{thomas} and
351 L{vincentys} and method L{Ellipsoid.distance2}.
353 @note: See note at function L{vincentys_}.
354 '''
355 return _dS(cosineLaw_, radius, wrap, lat1, lon1, lat2, lon2)
358def cosineLaw_(phi2, phi1, lam21):
359 '''Compute the I{angular} distance between two points using the U{spherical Law of
360 Cosines<https://www.Movable-Type.co.UK/scripts/latlong.html#cosine-law>} formula.
362 @arg phi2: End latitude (C{radians}).
363 @arg phi1: Start latitude (C{radians}).
364 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
366 @return: Angular distance (C{radians}).
368 @see: Functions L{cosineLaw}, L{cosineAndoyerLambert_},
369 L{cosineForsytheAndoyerLambert_}, L{euclidean_},
370 L{flatLocal_}/L{hubeny_}, L{flatPolar_}, L{haversine_},
371 L{thomas_} and L{vincentys_}.
373 @note: See note at function L{vincentys_}.
374 '''
375 return _sincosa6(phi2, phi1, lam21)[4]
378def _d3(wrap, lat1, lon1, lat2, lon2):
379 '''(INTERNAL) Helper for _dE, _dS and _eA.
380 '''
381 if wrap:
382 d_lon, lat2, _ = _Wrap.latlon3(lon1, lat2, lon2, wrap)
383 return radians(lat2), Phid(lat1=lat1), radians(d_lon)
384 else: # for backward compaibility
385 return Phid(lat2=lat2), Phid(lat1=lat1), Phid(d_lon=lon2 - lon1)
388def _dE(func_, earth, *wrap_lls):
389 '''(INTERNAL) Helper for ellipsoidal distances.
390 '''
391 E = _ellipsoidal(earth, func_)
392 r = func_(*_d3(*wrap_lls), datum=E)
393 return r * E.a
396def _dS(func_, radius, *wrap_lls, **adjust):
397 '''(INTERNAL) Helper for spherical distances.
398 '''
399 r = func_(*_d3(*wrap_lls), **adjust)
400 if radius is not R_M:
401 _, lat1, _, lat2, _ = wrap_lls
402 radius = _mean_radius(radius, lat1, lat2)
403 return r * radius
406def _eA(excess_, radius, *wrap_lls):
407 '''(INTERNAL) Helper for spherical excess or area.
408 '''
409 r = excess_(*_d3(*wrap_lls))
410 if radius:
411 _, lat1, _, lat2, _ = wrap_lls
412 r *= _mean_radius(radius, lat1, lat2)**2
413 return r
416def _ellipsoidal(earth, where):
417 '''(INTERNAL) Helper for distances.
418 '''
419 return _EWGS84 if earth in (_WGS84, _EWGS84) else (
420 earth if isinstance(earth, Ellipsoid) else
421 (earth if isinstance(earth, Datum) else # PYCHOK indent
422 _ellipsoidal_datum(earth, name__=where)).ellipsoid)
425def equirectangular(lat1, lon1, lat2, lon2, radius=R_M, **adjust_limit_wrap):
426 '''Compute the distance between two points using the U{Equirectangular Approximation
427 / Projection<https://www.Movable-Type.co.UK/scripts/latlong.html#equirectangular>}.
429 @arg lat1: Start latitude (C{degrees}).
430 @arg lon1: Start longitude (C{degrees}).
431 @arg lat2: End latitude (C{degrees}).
432 @arg lon2: End longitude (C{degrees}).
433 @kwarg radius: Mean earth radius (C{meter}), datum (L{Datum}) or ellipsoid
434 (L{Ellipsoid}, L{Ellipsoid2} or L{a_f2Tuple}).
435 @kwarg adjust_limit_wrap: Optional keyword arguments for function L{equirectangular4}.
437 @return: Distance (C{meter}, same units as B{C{radius}} or the ellipsoid or datum axes).
439 @raise TypeError: Invalid B{C{radius}}.
441 @see: Function L{equirectangular4} for more details, the available B{C{options}},
442 errors, restrictions and other, approximate or accurate distance functions.
443 '''
444 d = sqrt(equirectangular4(Lat(lat1=lat1), Lon(lon1=lon1),
445 Lat(lat2=lat2), Lon(lon2=lon2),
446 **adjust_limit_wrap).distance2) # PYCHOK 4 vs 2-3
447 return degrees2m(d, radius=_mean_radius(radius, lat1, lat2))
450def _equirectangular(lat1, lon1, lat2, lon2, **adjust_limit_wrap):
451 '''(INTERNAL) Helper for the L{frechet._FrechetMeterRadians}
452 and L{hausdorff._HausdorffMeterRedians} classes.
453 '''
454 return equirectangular4(lat1, lon1, lat2, lon2, **adjust_limit_wrap).distance2 * _RADIANS2
457def equirectangular4(lat1, lon1, lat2, lon2, adjust=True, limit=45, wrap=False):
458 '''Compute the distance between two points using the U{Equirectangular Approximation
459 / Projection<https://www.Movable-Type.co.UK/scripts/latlong.html#equirectangular>}.
461 This approximation is valid for short distance of several hundred Km or Miles, see
462 the B{C{limit}} keyword argument and L{LimitError}.
464 @arg lat1: Start latitude (C{degrees}).
465 @arg lon1: Start longitude (C{degrees}).
466 @arg lat2: End latitude (C{degrees}).
467 @arg lon2: End longitude (C{degrees}).
468 @kwarg adjust: Adjust the wrapped, unrolled longitudinal delta by the cosine of the mean
469 latitude (C{bool}).
470 @kwarg limit: Optional limit for lat- and longitudinal deltas (C{degrees}) or C{None}
471 or C{0} for unlimited.
472 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll B{C{lat2}} and B{C{lon2}}
473 (C{bool}).
475 @return: A L{Distance4Tuple}C{(distance2, delta_lat, delta_lon, unroll_lon2)}
476 in C{degrees squared}.
478 @raise LimitError: If the lat- and/or longitudinal delta exceeds the B{C{-limit..limit}}
479 range and L{limiterrors<pygeodesy.limiterrors>} is C{True}.
481 @see: U{Local, flat earth approximation<https://www.EdWilliams.org/avform.htm#flat>},
482 functions L{equirectangular}, L{cosineAndoyerLambert}, L{cosineForsytheAndoyerLambert},
483 L{cosineLaw}, L{euclidean}, L{flatLocal}/L{hubeny}, L{flatPolar}, L{haversine},
484 L{thomas} and L{vincentys} and methods L{Ellipsoid.distance2}, C{LatLon.distanceTo*}
485 and C{LatLon.equirectangularTo}.
486 '''
487 d_lon, lat2, ulon2 = _Wrap.latlon3(lon1, lat2, lon2, wrap)
488 d_lat = lat2 - lat1
490 if limit and limit > 0 and limiterrors():
491 d = max(fabs(d_lat), fabs(d_lon))
492 if d > limit:
493 t = _SPACE_(_delta_, Fmt.PAREN_g(d), Fmt.exceeds_limit(limit))
494 s = unstr(equirectangular4, lat1, lon1, lat2, lon2,
495 limit=limit, wrap=wrap)
496 raise LimitError(s, txt=t)
498 if adjust: # scale delta lon
499 d_lon *= _scale_deg(lat1, lat2)
501 d2 = hypot2(d_lat, d_lon) # degrees squared!
502 return Distance4Tuple(d2, d_lat, d_lon, ulon2 - lon2)
505def euclidean(lat1, lon1, lat2, lon2, radius=R_M, adjust=True, wrap=False):
506 '''Approximate the C{Euclidean} distance between two (spherical) points.
508 @arg lat1: Start latitude (C{degrees}).
509 @arg lon1: Start longitude (C{degrees}).
510 @arg lat2: End latitude (C{degrees}).
511 @arg lon2: End longitude (C{degrees}).
512 @kwarg radius: Mean earth radius (C{meter}), datum (L{Datum})
513 or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
514 L{a_f2Tuple}) to use.
515 @kwarg adjust: Adjust the longitudinal delta by the cosine of
516 the mean latitude (C{bool}).
517 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll B{C{lat2}}
518 and B{C{lon2}} (C{bool}).
520 @return: Distance (C{meter}, same units as B{C{radius}} or the
521 ellipsoid or datum axes).
523 @raise TypeError: Invalid B{C{radius}}.
525 @see: U{Distance between two (spherical) points
526 <https://www.EdWilliams.org/avform.htm#Dist>}, functions L{euclid},
527 L{euclidean_}, L{cosineAndoyerLambert}, L{cosineForsytheAndoyerLambert},
528 L{cosineLaw}, L{equirectangular}, L{flatLocal}/L{hubeny}, L{flatPolar},
529 L{haversine}, L{thomas} and L{vincentys} and methods L{Ellipsoid.distance2},
530 C{LatLon.distanceTo*} and C{LatLon.equirectangularTo}.
531 '''
532 return _dS(euclidean_, radius, wrap, lat1, lon1, lat2, lon2, adjust=adjust)
535def euclidean_(phi2, phi1, lam21, adjust=True):
536 '''Approximate the I{angular} C{Euclidean} distance between two (spherical) points.
538 @arg phi2: End latitude (C{radians}).
539 @arg phi1: Start latitude (C{radians}).
540 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
541 @kwarg adjust: Adjust the longitudinal delta by the cosine
542 of the mean latitude (C{bool}).
544 @return: Angular distance (C{radians}).
546 @see: Functions L{euclid}, L{euclidean}, L{cosineAndoyerLambert_},
547 L{cosineForsytheAndoyerLambert_}, L{cosineLaw_},
548 L{flatLocal_}/L{hubeny_}, L{flatPolar_}, L{haversine_},
549 L{thomas_} and L{vincentys_}.
550 '''
551 if adjust:
552 lam21 *= _scale_rad(phi2, phi1)
553 return euclid(phi2 - phi1, lam21)
556def excessAbc_(A, b, c):
557 '''Compute the I{spherical excess} C{E} of a (spherical) triangle from two sides
558 and the included (small) angle.
560 @arg A: An interior triangle angle (C{radians}).
561 @arg b: Frist adjacent triangle side (C{radians}).
562 @arg c: Second adjacent triangle side (C{radians}).
564 @return: Spherical excess (C{radians}).
566 @raise UnitError: Invalid B{C{A}}, B{C{b}} or B{C{c}}.
568 @see: Functions L{excessGirard_}, L{excessLHuilier_} and U{Spherical
569 trigonometry<https://WikiPedia.org/wiki/Spherical_trigonometry>}.
570 '''
571 A = Radians_(A=A)
572 b = Radians_(b=b) * _0_5
573 c = Radians_(c=c) * _0_5
575 sA, cA, sb, cb, sc, cc = sincos2_(A, b, c)
576 return atan2(sA * sb * sc, cb * cc + cA * sb * sc) * _2_0
579def excessCagnoli_(a, b, c):
580 '''Compute the I{spherical excess} C{E} of a (spherical) triangle using U{Cagnoli's
581 <https://Zenodo.org/record/35392>} (D.34) formula.
583 @arg a: First triangle side (C{radians}).
584 @arg b: Second triangle side (C{radians}).
585 @arg c: Third triangle side (C{radians}).
587 @return: Spherical excess (C{radians}).
589 @raise UnitError: Invalid B{C{a}}, B{C{b}} or B{C{c}}.
591 @see: Function L{excessLHuilier_} and U{Spherical trigonometry
592 <https://WikiPedia.org/wiki/Spherical_trigonometry>}.
593 '''
594 a = Radians_(a=a)
595 b = Radians_(b=b)
596 c = Radians_(c=c)
598 s = fsumf_(a, b, c) * _0_5
599 _s = sin
600 r = _s(s) * _s(s - a) * _s(s - b) * _s(s - c)
601 c = cos(a * _0_5) * cos(b * _0_5) * cos(c * _0_5)
602 r = asin(sqrt(r) * _0_5 / c) if c and r > 0 else _0_0
603 return Radians(Cagnoli=r * _2_0)
606def excessGirard_(A, B, C):
607 '''Compute the I{spherical excess} C{E} of a (spherical) triangle using U{Girard's
608 <https://MathWorld.Wolfram.com/GirardsSphericalExcessFormula.html>} formula.
610 @arg A: First interior triangle angle (C{radians}).
611 @arg B: Second interior triangle angle (C{radians}).
612 @arg C: Third interior triangle angle (C{radians}).
614 @return: Spherical excess (C{radians}).
616 @raise UnitError: Invalid B{C{A}}, B{C{B}} or B{C{C}}.
618 @see: Function L{excessLHuilier_} and U{Spherical trigonometry
619 <https://WikiPedia.org/wiki/Spherical_trigonometry>}.
620 '''
621 return Radians(Girard=fsumf_(Radians_(A=A),
622 Radians_(B=B),
623 Radians_(C=C), -PI))
626def excessLHuilier_(a, b, c):
627 '''Compute the I{spherical excess} C{E} of a (spherical) triangle using U{L'Huilier's
628 <https://MathWorld.Wolfram.com/LHuiliersTheorem.html>}'s Theorem.
630 @arg a: First triangle side (C{radians}).
631 @arg b: Second triangle side (C{radians}).
632 @arg c: Third triangle side (C{radians}).
634 @return: Spherical excess (C{radians}).
636 @raise UnitError: Invalid B{C{a}}, B{C{b}} or B{C{c}}.
638 @see: Function L{excessCagnoli_}, L{excessGirard_} and U{Spherical
639 trigonometry<https://WikiPedia.org/wiki/Spherical_trigonometry>}.
640 '''
641 a = Radians_(a=a)
642 b = Radians_(b=b)
643 c = Radians_(c=c)
645 s = fsumf_(a, b, c) * _0_5
646 _t = tan_2
647 r = _t(s) * _t(s - a) * _t(s - b) * _t(s - c)
648 r = atan(sqrt(r)) if r > 0 else _0_0
649 return Radians(LHuilier=r * _4_0)
652def excessKarney(lat1, lon1, lat2, lon2, radius=R_M, wrap=False):
653 '''Compute the surface area of a (spherical) quadrilateral bounded by a
654 segment of a great circle, two meridians and the equator using U{Karney's
655 <https://MathOverflow.net/questions/97711/the-area-of-spherical-polygons>}
656 method.
658 @arg lat1: Start latitude (C{degrees}).
659 @arg lon1: Start longitude (C{degrees}).
660 @arg lat2: End latitude (C{degrees}).
661 @arg lon2: End longitude (C{degrees}).
662 @kwarg radius: Mean earth radius (C{meter}), datum (L{Datum})
663 or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
664 L{a_f2Tuple}) or C{None}.
665 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll
666 B{C{lat2}} and B{C{lon2}} (C{bool}).
668 @return: Surface area, I{signed} (I{square} C{meter} or the same units as
669 B{C{radius}} I{squared}) or the I{spherical excess} (C{radians})
670 if C{B{radius}=0} or C{None}.
672 @raise TypeError: Invalid B{C{radius}}.
674 @raise UnitError: Invalid B{C{lat2}} or B{C{lat1}}.
676 @raise ValueError: Semi-circular longitudinal delta.
678 @see: Functions L{excessKarney_} and L{excessQuad}.
679 '''
680 return _eA(excessKarney_, radius, wrap, lat1, lon1, lat2, lon2)
683def excessKarney_(phi2, phi1, lam21):
684 '''Compute the I{spherical excess} C{E} of a (spherical) quadrilateral bounded by
685 a segment of a great circle, two meridians and the equator using U{Karney's
686 <https://MathOverflow.net/questions/97711/the-area-of-spherical-polygons>}
687 method.
689 @arg phi2: End latitude (C{radians}).
690 @arg phi1: Start latitude (C{radians}).
691 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
693 @return: Spherical excess, I{signed} (C{radians}).
695 @raise ValueError: Semi-circular longitudinal delta B{C{lam21}}.
697 @see: Function L{excessKarney} and U{Area of a spherical polygon
698 <https://MathOverflow.net/questions/97711/the-area-of-spherical-polygons>}.
699 '''
700 # from: Veness <https://www.Movable-Type.co.UK/scripts/latlong.html> Area
701 # method due to Karney: for each edge of the polygon,
702 #
703 # tan(Δλ / 2) · (tan(φ1 / 2) + tan(φ2 / 2))
704 # tan(E / 2) = -----------------------------------------
705 # 1 + tan(φ1 / 2) · tan(φ2 / 2)
706 #
707 # where E is the spherical excess of the trapezium obtained by extending
708 # the edge to the equator-circle vector for each edge (see also ***).
709 _t = tan_2
710 t2 = _t(phi2)
711 t1 = _t(phi1)
712 t = _t(lam21, lam21=None)
713 return Radians(Karney=atan2(t * (t1 + t2),
714 _1_0 + (t1 * t2)) * _2_0)
717# ***) Original post no longer available, following is a copy of the main part
718# <http://OSGeo-org.1560.x6.Nabble.com/Area-of-a-spherical-polygon-td3841625.html>
719#
720# The area of a polygon on a (unit) sphere is given by the spherical excess
721#
722# A = 2 * pi - sum(exterior angles)
723#
724# However this is badly conditioned if the polygon is small. In this case, use
725#
726# A = sum(S12{i, i+1}) over the edges of the polygon
727#
728# where S12 is the area of the quadrilateral bounded by an edge of the polygon,
729# two meridians and the equator, i.e. with vertices (phi1, lambda1), (phi2,
730# lambda2), (0, lambda1) and (0, lambda2). S12 is given by
731#
732# tan(S12 / 2) = tan(lambda21 / 2) * (tan(phi1 / 2) + tan(phi2 / 2)) /
733# (tan(phi1 / 2) * tan(phi2 / 2) + 1)
734#
735# = tan(lambda21 / 2) * tanh((Lamb(phi1) + Lamb(phi2)) / 2)
736#
737# where lambda21 = lambda2 - lambda1 and Lamb(x) is the Lambertian (or the
738# inverse Gudermannian) function
739#
740# Lambertian(x) = asinh(tan(x)) = atanh(sin(x)) = 2 * atanh(tan(x / 2))
741#
742# Notes: The formula for S12 is exact, except that...
743# - it is indeterminate if an edge is a semi-circle
744# - the formula for A applies only if the polygon does not include a pole
745# (if it does, then add +/- 2 * pi to the result)
746# - in the limit of small phi and lambda, S12 reduces to the trapezoidal
747# formula, S12 = (lambda2 - lambda1) * (phi1 + phi2) / 2
748# - I derived this result from the equation for the area of a spherical
749# triangle in terms of two edges and the included angle given by, e.g.
750# U{Todhunter, I. - Spherical Trigonometry (1871), Sec. 103, Eq. (2)
751# <http://Books.Google.com/books?id=3uBHAAAAIAAJ&pg=PA71>}
752# - I would be interested to know if this formula for S12 is already known
753# - Charles Karney
756def excessQuad(lat1, lon1, lat2, lon2, radius=R_M, wrap=False):
757 '''Compute the surface area of a (spherical) quadrilateral bounded by a segment
758 of a great circle, two meridians and the equator.
760 @arg lat1: Start latitude (C{degrees}).
761 @arg lon1: Start longitude (C{degrees}).
762 @arg lat2: End latitude (C{degrees}).
763 @arg lon2: End longitude (C{degrees}).
764 @kwarg radius: Mean earth radius (C{meter}), datum (L{Datum})
765 or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
766 L{a_f2Tuple}) or C{None}.
767 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll
768 B{C{lat2}} and B{C{lon2}} (C{bool}).
770 @return: Surface area, I{signed} (I{square} C{meter} or the same units as
771 B{C{radius}} I{squared}) or the I{spherical excess} (C{radians})
772 if C{B{radius}=0} or C{None}.
774 @raise TypeError: Invalid B{C{radius}}.
776 @raise UnitError: Invalid B{C{lat2}} or B{C{lat1}}.
778 @see: Function L{excessQuad_} and L{excessKarney}.
779 '''
780 return _eA(excessQuad_, radius, wrap, lat1, lon1, lat2, lon2)
783def excessQuad_(phi2, phi1, lam21):
784 '''Compute the I{spherical excess} C{E} of a (spherical) quadrilateral bounded
785 by a segment of a great circle, two meridians and the equator.
787 @arg phi2: End latitude (C{radians}).
788 @arg phi1: Start latitude (C{radians}).
789 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
791 @return: Spherical excess, I{signed} (C{radians}).
793 @see: Function L{excessQuad} and U{Spherical trigonometry
794 <https://WikiPedia.org/wiki/Spherical_trigonometry>}.
795 '''
796 s = sin((phi2 + phi1) * _0_5)
797 c = cos((phi2 - phi1) * _0_5)
798 return Radians(Quad=atan2(tan_2(lam21) * s, c) * _2_0)
801def flatLocal(lat1, lon1, lat2, lon2, datum=_WGS84, scaled=True, wrap=False):
802 '''Compute the distance between two (ellipsoidal) points using
803 the U{ellipsoidal Earth to plane projection<https://WikiPedia.org/
804 wiki/Geographical_distance#Ellipsoidal_Earth_projected_to_a_plane>}
805 aka U{Hubeny<https://www.OVG.AT/de/vgi/files/pdf/3781/>} formula.
807 @arg lat1: Start latitude (C{degrees}).
808 @arg lon1: Start longitude (C{degrees}).
809 @arg lat2: End latitude (C{degrees}).
810 @arg lon2: End longitude (C{degrees}).
811 @kwarg datum: Datum (L{Datum}) or ellipsoid (L{Ellipsoid},
812 L{Ellipsoid2} or L{a_f2Tuple}) to use.
813 @kwarg scaled: Scale prime_vertical by C{cos(B{phi})} (C{bool}),
814 see method L{pygeodesy.Ellipsoid.roc2_}.
815 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll
816 B{C{lat2}} and B{C{lon2}} (C{bool}).
818 @return: Distance (C{meter}, same units as the B{C{datum}}'s
819 ellipsoid axes).
821 @raise TypeError: Invalid B{C{datum}}.
823 @note: The meridional and prime_vertical radii of curvature
824 are taken and scaled at the mean of both latitude.
826 @see: Functions L{flatLocal_} or L{hubeny_}, L{cosineLaw}, L{flatPolar},
827 L{cosineAndoyerLambert}, L{cosineForsytheAndoyerLambert},
828 L{equirectangular}, L{euclidean}, L{haversine}, L{thomas},
829 L{vincentys}, method L{Ellipsoid.distance2} and U{local, flat
830 earth approximation<https://www.EdWilliams.org/avform.htm#flat>}.
831 '''
832 E = _ellipsoidal(datum, flatLocal)
833 return E._hubeny_2(*_d3(wrap, lat1, lon1, lat2, lon2),
834 scaled=scaled, squared=False) * E.a
836hubeny = flatLocal # PYCHOK for Karl Hubeny
839def flatLocal_(phi2, phi1, lam21, datum=_WGS84, scaled=True):
840 '''Compute the I{angular} distance between two (ellipsoidal) points using
841 the U{ellipsoidal Earth to plane projection<https://WikiPedia.org/
842 wiki/Geographical_distance#Ellipsoidal_Earth_projected_to_a_plane>}
843 aka U{Hubeny<https://www.OVG.AT/de/vgi/files/pdf/3781/>} formula.
845 @arg phi2: End latitude (C{radians}).
846 @arg phi1: Start latitude (C{radians}).
847 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
848 @kwarg datum: Datum (L{Datum}) or ellipsoid (L{Ellipsoid},
849 L{Ellipsoid2} or L{a_f2Tuple}) to use.
850 @kwarg scaled: Scale prime_vertical by C{cos(B{phi})} (C{bool}),
851 see method L{pygeodesy.Ellipsoid.roc2_}.
853 @return: Angular distance (C{radians}).
855 @raise TypeError: Invalid B{C{datum}}.
857 @note: The meridional and prime_vertical radii of curvature
858 are taken and scaled I{at the mean of both latitude}.
860 @see: Functions L{flatLocal} or L{hubeny}, L{cosineAndoyerLambert_},
861 L{cosineForsytheAndoyerLambert_}, L{cosineLaw_}, L{flatPolar_},
862 L{euclidean_}, L{haversine_}, L{thomas_} and L{vincentys_} and
863 U{local, flat earth approximation
864 <https://www.EdWilliams.org/avform.htm#flat>}.
865 '''
866 E = _ellipsoidal(datum, flatLocal_)
867 return E._hubeny_2(phi2, phi1, lam21, scaled=scaled, squared=False)
869hubeny_ = flatLocal_ # PYCHOK for Karl Hubeny
872def flatPolar(lat1, lon1, lat2, lon2, radius=R_M, wrap=False):
873 '''Compute the distance between two (spherical) points using
874 the U{polar coordinate flat-Earth <https://WikiPedia.org/wiki/
875 Geographical_distance#Polar_coordinate_flat-Earth_formula>}
876 formula.
878 @arg lat1: Start latitude (C{degrees}).
879 @arg lon1: Start longitude (C{degrees}).
880 @arg lat2: End latitude (C{degrees}).
881 @arg lon2: End longitude (C{degrees}).
882 @kwarg radius: Mean earth radius (C{meter}), datum (L{Datum})
883 or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
884 L{a_f2Tuple}) to use.
885 @kwarg wrap: If C{True}, wrap or I{normalize} and B{C{lat2}}
886 and B{C{lon2}} (C{bool}).
888 @return: Distance (C{meter}, same units as B{C{radius}} or the
889 ellipsoid or datum axes).
891 @raise TypeError: Invalid B{C{radius}}.
893 @see: Functions L{flatPolar_}, L{cosineAndoyerLambert},
894 L{cosineForsytheAndoyerLambert},L{cosineLaw},
895 L{flatLocal}/L{hubeny}, L{equirectangular},
896 L{euclidean}, L{haversine}, L{thomas} and
897 L{vincentys}.
898 '''
899 return _dS(flatPolar_, radius, wrap, lat1, lon1, lat2, lon2)
902def flatPolar_(phi2, phi1, lam21):
903 '''Compute the I{angular} distance between two (spherical) points
904 using the U{polar coordinate flat-Earth<https://WikiPedia.org/wiki/
905 Geographical_distance#Polar_coordinate_flat-Earth_formula>}
906 formula.
908 @arg phi2: End latitude (C{radians}).
909 @arg phi1: Start latitude (C{radians}).
910 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
912 @return: Angular distance (C{radians}).
914 @see: Functions L{flatPolar}, L{cosineAndoyerLambert_},
915 L{cosineForsytheAndoyerLambert_}, L{cosineLaw_},
916 L{euclidean_}, L{flatLocal_}/L{hubeny_}, L{haversine_},
917 L{thomas_} and L{vincentys_}.
918 '''
919 a = fabs(PI_2 - phi1) # co-latitude
920 b = fabs(PI_2 - phi2) # co-latitude
921 if a < b:
922 a, b = b, a
923 if a < EPS0:
924 a = _0_0
925 elif b > 0:
926 b = b / a # /= chokes PyChecker
927 c = b * cos(lam21) * _2_0
928 c = fsumf_(_1_0, b**2, -fabs(c))
929 a *= sqrt0(c)
930 return a
933def _hartzell(pov, los, earth, **kwds):
934 '''(INTERNAL) Helper for C{CartesianBase.hartzell} and C{LatLonBase.hartzell}.
935 '''
936 if earth is None:
937 earth = pov.datum
938 else:
939 earth = _spherical_datum(earth, name__=hartzell)
940 pov = pov.toDatum(earth)
941 h = pov.height
942 if h < 0: # EPS0
943 t = _SPACE_(Fmt.PARENSPACED(height=h), _inside_)
944 raise IntersectionError(pov=pov, earth=earth, txt=t)
945 return hartzell(pov, los=los, earth=earth, **kwds) if h > 0 else pov # EPS0
948def hartzell(pov, los=False, earth=_WGS84, **name_LatLon_and_kwds):
949 '''Compute the intersection of the earth's surface and a Line-Of-Sight from
950 a Point-Of-View in space.
952 @arg pov: Point-Of-View outside the earth (C{LatLon}, C{Cartesian},
953 L{Ecef9Tuple} or L{Vector3d}).
954 @kwarg los: Line-Of-Sight, I{direction} to earth (L{Los}, L{Vector3d}),
955 C{True} for the I{normal, plumb} onto the surface or C{False}
956 or C{None} to point to the center of the earth.
957 @kwarg earth: The earth model (L{Datum}, L{Ellipsoid}, L{Ellipsoid2},
958 L{a_f2Tuple} or a C{scalar} earth radius in C{meter}).
959 @kwarg name_LatLon_and_kwds: Optional, overriding C{B{name}="hartzell"}
960 (C{str}), class C{B{LatLon}=None} to return the intersection
961 plus additional C{LatLon} keyword arguments, include the
962 B{C{datum}} if different and to convert from B{C{earth}}.
964 @return: The intersection (L{Vector3d}, B{C{pov}}'s C{cartesian type} or the
965 given B{C{LatLon}} instance) with attribute C{height} set to the
966 distance to the B{C{pov}}.
968 @raise IntersectionError: Invalid B{C{pov}} or B{C{pov}} inside the earth or
969 invalid B{C{los}} or B{C{los}} points outside or
970 away from the earth.
972 @raise TypeError: Invalid B{C{earth}}, C{ellipsoid} or C{datum}.
974 @see: Class L{Los}, functions L{tyr3d} and L{hartzell4} and methods
975 L{Ellipsoid.hartzell4} and any C{Cartesian.hartzell} and C{LatLon.hartzell}.
976 '''
977 n, LatLon_and_kwds = _name2__(name_LatLon_and_kwds, name__=hartzell)
978 try:
979 D = _spherical_datum(earth, name__=hartzell)
980 r, h, i = _MODS.triaxials._hartzell3(pov, los, D.ellipsoid._triaxial)
982 C = _MODS.cartesianBase.CartesianBase
983 if LatLon_and_kwds:
984 c = C(r, datum=D)
985 r = c.toLatLon(**_xkwds(LatLon_and_kwds, height=h))
986 elif isinstance(r, C):
987 r.height = h
988 if i:
989 r._iteration = i
990 except Exception as x:
991 raise IntersectionError(pov=pov, los=los, earth=earth, cause=x,
992 **LatLon_and_kwds)
993 return _xnamed(r, n) if n else r
996def haversine(lat1, lon1, lat2, lon2, radius=R_M, wrap=False):
997 '''Compute the distance between two (spherical) points using the
998 U{Haversine<https://www.Movable-Type.co.UK/scripts/latlong.html>}
999 formula.
1001 @arg lat1: Start latitude (C{degrees}).
1002 @arg lon1: Start longitude (C{degrees}).
1003 @arg lat2: End latitude (C{degrees}).
1004 @arg lon2: End longitude (C{degrees}).
1005 @kwarg radius: Mean earth radius (C{meter}), datum (L{Datum})
1006 or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
1007 L{a_f2Tuple}) to use.
1008 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll
1009 B{C{lat2}} and B{C{lon2}} (C{bool}).
1011 @return: Distance (C{meter}, same units as B{C{radius}}).
1013 @raise TypeError: Invalid B{C{radius}}.
1015 @see: U{Distance between two (spherical) points
1016 <https://www.EdWilliams.org/avform.htm#Dist>}, functions
1017 L{cosineLaw}, L{cosineAndoyerLambert}, L{cosineForsytheAndoyerLambert},
1018 L{equirectangular}, L{euclidean}, L{flatLocal}/L{hubeny}, L{flatPolar},
1019 L{thomas} and L{vincentys} and methods L{Ellipsoid.distance2},
1020 C{LatLon.distanceTo*} and C{LatLon.equirectangularTo}.
1022 @note: See note at function L{vincentys_}.
1023 '''
1024 return _dS(haversine_, radius, wrap, lat1, lon1, lat2, lon2)
1027def haversine_(phi2, phi1, lam21):
1028 '''Compute the I{angular} distance between two (spherical) points
1029 using the U{Haversine<https://www.Movable-Type.co.UK/scripts/latlong.html>}
1030 formula.
1032 @arg phi2: End latitude (C{radians}).
1033 @arg phi1: Start latitude (C{radians}).
1034 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
1036 @return: Angular distance (C{radians}).
1038 @see: Functions L{haversine}, L{cosineAndoyerLambert_},
1039 L{cosineForsytheAndoyerLambert_}, L{cosineLaw_},
1040 L{euclidean_}, L{flatLocal_}/L{hubeny_}, L{flatPolar_},
1041 L{thomas_} and L{vincentys_}.
1043 @note: See note at function L{vincentys_}.
1044 '''
1045 def _hsin(rad):
1046 return sin(rad * _0_5)**2
1048 h = _hsin(phi2 - phi1) + cos(phi1) * cos(phi2) * _hsin(lam21) # haversine
1049 return atan2(sqrt0(h), sqrt0(_1_0 - h)) * _2_0 # == asin(sqrt(h)) * 2
1052def heightOf(angle, distance, radius=R_M):
1053 '''Determine the height above the (spherical) earth' surface after
1054 traveling along a straight line at a given tilt.
1056 @arg angle: Tilt angle above horizontal (C{degrees}).
1057 @arg distance: Distance along the line (C{meter} or same units as
1058 B{C{radius}}).
1059 @kwarg radius: Optional mean earth radius (C{meter}).
1061 @return: Height (C{meter}, same units as B{C{distance}} and B{C{radius}}).
1063 @raise ValueError: Invalid B{C{angle}}, B{C{distance}} or B{C{radius}}.
1065 @see: U{MultiDop geog_lib.GeogBeamHt<https://GitHub.com/NASA/MultiDop>}
1066 (U{Shapiro et al. 2009, JTECH
1067 <https://Journals.AMetSoc.org/doi/abs/10.1175/2009JTECHA1256.1>}
1068 and U{Potvin et al. 2012, JTECH
1069 <https://Journals.AMetSoc.org/doi/abs/10.1175/JTECH-D-11-00019.1>}).
1070 '''
1071 r = h = Radius(radius)
1072 d = fabs(Distance(distance))
1073 if d > h:
1074 d, h = h, d
1076 if d > EPS0: # and h > EPS0
1077 d = d / h # /= h chokes PyChecker
1078 s = sin(Phid(angle=angle, clip=_180_0))
1079 s = fsumf_(_1_0, s * d * _2_0, d**2)
1080 if s > 0:
1081 return h * sqrt(s) - r
1083 raise _ValueError(angle=angle, distance=distance, radius=radius)
1086def heightOrthometric(h_ll, N):
1087 '''Get the I{orthometric} height B{H}, the height above the geoid, earth surface.
1089 @arg h_ll: The height above the ellipsoid (C{meter}) or an I{ellipsoidal}
1090 location (C{LatLon} with a C{height} or C{h} attribute).
1091 @arg N: The I{geoid} height (C{meter}), the height of the geoid above the
1092 ellipsoid at the same B{C{h_ll}} location.
1094 @return: I{Orthometric} height C{B{H} = B{h} - B{N}} (C{meter}, same units
1095 as B{C{h}} and B{C{N}}).
1097 @see: U{Ellipsoid, Geoid, and Othometric Heights<https://www.NGS.NOAA.gov/
1098 GEOID/PRESENTATIONS/2007_02_24_CCPS/Roman_A_PLSC2007notes.pdf>}, page
1099 6 and module L{pygeodesy.geoids}.
1100 '''
1101 h = h_ll if _isHeight(h_ll) else _xattr(h_ll, height=_xattr(h_ll, h=0))
1102 return Height(H=Height(h=h) - Height(N=N))
1105def horizon(height, radius=R_M, refraction=False):
1106 '''Determine the distance to the horizon from a given altitude above the
1107 (spherical) earth.
1109 @arg height: Altitude (C{meter} or same units as B{C{radius}}).
1110 @kwarg radius: Optional mean earth radius (C{meter}).
1111 @kwarg refraction: Consider atmospheric refraction (C{bool}).
1113 @return: Distance (C{meter}, same units as B{C{height}} and B{C{radius}}).
1115 @raise ValueError: Invalid B{C{height}} or B{C{radius}}.
1117 @see: U{Distance to horizon<https://www.EdWilliams.org/avform.htm#Horizon>}.
1118 '''
1119 h, r = Height(height), Radius(radius)
1120 if min(h, r) < 0:
1121 raise _ValueError(height=height, radius=radius)
1123 d2 = ((r * 2.415750694528) if refraction else # 2.0 / 0.8279
1124 fsumf_(r, r, h)) * h
1125 return sqrt0(d2)
1128class _idllmn6(object): # see also .geodesicw._wargs, .latlonBase._toCartesian3, .vector2d._numpy
1129 '''(INTERNAL) Helper for C{intersection2} and C{intersections2}.
1130 '''
1131 @contextmanager # <https://www.Python.org/dev/peps/pep-0343/> Examples
1132 def __call__(self, datum, lat1, lon1, lat2, lon2, small, wrap, s, **kwds):
1133 try:
1134 if wrap:
1135 _, lat2, lon2 = _Wrap.latlon3(lon1, lat2, lon2, wrap)
1136 kwds = _xkwds(kwds, wrap=wrap) # for _xError
1137 m = small if small is _100km else Meter_(small=small)
1138 n = _dunder_nameof(intersections2 if s else intersection2)
1139 if datum is None or euclidean(lat1, lon1, lat2, lon2) < m:
1140 d, m = None, _MODS.vector3d
1141 _i = m._intersects2 if s else m._intersect3d3
1142 elif _isRadius(datum) and datum < 0 and not s:
1143 d = _spherical_datum(-datum, name=n)
1144 m = _MODS.sphericalNvector
1145 _i = m.intersection
1146 else:
1147 d = _spherical_datum(datum, name=n)
1148 if d.isSpherical:
1149 m = _MODS.sphericalTrigonometry
1150 _i = m._intersects2 if s else m._intersect
1151 elif d.isEllipsoidal:
1152 try:
1153 if d.ellipsoid.geodesic:
1154 pass
1155 m = _MODS.ellipsoidalKarney
1156 except ImportError:
1157 m = _MODS.ellipsoidalExact
1158 _i = m._intersections2 if s else m._intersection3 # ellispoidalBaseDI
1159 else:
1160 raise _TypeError(datum=datum)
1161 yield _i, d, lat2, lon2, m, n
1163 except (TypeError, ValueError) as x:
1164 raise _xError(x, lat1=lat1, lon1=lon1, datum=datum,
1165 lat2=lat2, lon2=lon2, small=small, **kwds)
1167_idllmn6 = _idllmn6() # PYCHOK singleton
1170def intersection2(lat1, lon1, bearing1,
1171 lat2, lon2, bearing2, datum=None, wrap=False, small=_100km): # was=True
1172 '''I{Conveniently} compute the intersection of two lines each defined
1173 by a (geodetic) point and a bearing from North, using either ...
1175 1) L{vector3d.intersection3d3} for B{C{small}} distances (below 100 Km
1176 or about 0.88 degrees) or if I{no} B{C{datum}} is specified, or ...
1178 2) L{sphericalTrigonometry.intersection} for a spherical B{C{datum}}
1179 or a C{scalar B{datum}} representing the earth radius, conventionally
1180 in C{meter} or ...
1182 3) L{sphericalNvector.intersection} if B{C{datum}} is a I{negative}
1183 C{scalar}, (negative) earth radius, conventionally in C{meter} or ...
1185 4) L{ellipsoidalKarney.intersection3} for an ellipsoidal B{C{datum}}
1186 and if I{Karney}'s U{geographiclib<https://PyPI.org/project/geographiclib>}
1187 is installed, otherwise ...
1189 5) L{ellipsoidalExact.intersection3}, provided B{C{datum}} is ellipsoidal.
1191 @arg lat1: Latitude of the first point (C{degrees}).
1192 @arg lon1: Longitude of the first point (C{degrees}).
1193 @arg bearing1: Bearing at the first point (compass C{degrees}).
1194 @arg lat2: Latitude of the second point (C{degrees}).
1195 @arg lon2: Longitude of the second point (C{degrees}).
1196 @arg bearing2: Bearing at the second point (compass C{degrees}).
1197 @kwarg datum: Optional datum (L{Datum}) or ellipsoid (L{Ellipsoid},
1198 L{Ellipsoid2} or L{a_f2Tuple}) or C{scalar} earth
1199 radius (C{meter}, same units as B{C{radius1}} and
1200 B{C{radius2}}) or C{None}.
1201 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll B{C{lat2}}
1202 and B{C{lon2}} (C{bool}).
1203 @kwarg small: Upper limit for small distances (C{meter}).
1205 @return: A L{LatLon2Tuple}C{(lat, lon)} with the lat- and
1206 longitude of the intersection point.
1208 @raise IntersectionError: Ambiguous or infinite intersection
1209 or colinear, parallel or otherwise
1210 non-intersecting lines.
1212 @raise TypeError: Invalid B{C{datum}}.
1214 @raise UnitError: Invalid B{C{lat1}}, B{C{lon1}}, B{C{bearing1}},
1215 B{C{lat2}}, B{C{lon2}} or B{C{bearing2}}.
1217 @see: Method L{RhumbLine.intersection2}.
1219 @note: The returned intersections may be near-antipodal.
1220 '''
1221 b1 = Bearing(bearing1=bearing1)
1222 b2 = Bearing(bearing2=bearing2)
1223 with _idllmn6(datum, lat1, lon1, lat2, lon2,
1224 small, wrap, False, bearing1=b1, bearing2=b2) as t:
1225 _i, d, lat2, lon2, m, n = t
1226 if d is None:
1227 t, _, _ = _i(m.Vector3d(lon1, lat1, 0), b1,
1228 m.Vector3d(lon2, lat2, 0), b2, useZ=False)
1229 t = LatLon2Tuple(t.y, t.x, name=n)
1231 else:
1232 t = _i(m.LatLon(lat1, lon1, datum=d), b1,
1233 m.LatLon(lat2, lon2, datum=d), b2, height=0, wrap=False)
1234 if isinstance(t, Intersection3Tuple): # ellipsoidal
1235 t, _, _ = t
1236 t = LatLon2Tuple(t.lat, t.lon, name=n)
1237 return t
1240def intersections2(lat1, lon1, radius1,
1241 lat2, lon2, radius2, datum=None, wrap=False, small=_100km): # was=True
1242 '''I{Conveniently} compute the intersections of two circles each defined
1243 by a (geodetic) center point and a radius, using either ...
1245 1) L{vector3d.intersections2} for B{C{small}} distances (below 100 Km
1246 or about 0.88 degrees) or if I{no} B{C{datum}} is specified, or ...
1248 2) L{sphericalTrigonometry.intersections2} for a spherical B{C{datum}}
1249 or a C{scalar B{datum}} representing the earth radius, conventionally
1250 in C{meter} or ...
1252 3) L{ellipsoidalKarney.intersections2} for an ellipsoidal B{C{datum}}
1253 and if I{Karney}'s U{geographiclib<https://PyPI.org/project/geographiclib>}
1254 is installed, otherwise ...
1256 4) L{ellipsoidalExact.intersections2}, provided B{C{datum}} is ellipsoidal.
1258 @arg lat1: Latitude of the first circle center (C{degrees}).
1259 @arg lon1: Longitude of the first circle center (C{degrees}).
1260 @arg radius1: Radius of the first circle (C{meter}, conventionally).
1261 @arg lat2: Latitude of the second circle center (C{degrees}).
1262 @arg lon2: Longitude of the second circle center (C{degrees}).
1263 @arg radius2: Radius of the second circle (C{meter}, same units as B{C{radius1}}).
1264 @kwarg datum: Optional datum (L{Datum}) or ellipsoid (L{Ellipsoid},
1265 L{Ellipsoid2} or L{a_f2Tuple}) or C{scalar} earth
1266 radius (C{meter}, same units as B{C{radius1}} and
1267 B{C{radius2}}) or C{None}.
1268 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll B{C{lat2}}
1269 and B{C{lon2}} (C{bool}).
1270 @kwarg small: Upper limit for small distances (C{meter}).
1272 @return: 2-Tuple of the intersection points, each a
1273 L{LatLon2Tuple}C{(lat, lon)}. For abutting circles, the
1274 points are the same instance, aka the I{radical center}.
1276 @raise IntersectionError: Concentric, antipodal, invalid or
1277 non-intersecting circles or no
1278 convergence.
1280 @raise TypeError: Invalid B{C{datum}}.
1282 @raise UnitError: Invalid B{C{lat1}}, B{C{lon1}}, B{C{radius1}},
1283 B{C{lat2}}, B{C{lon2}} or B{C{radius2}}.
1284 '''
1285 r1 = Radius_(radius1=radius1)
1286 r2 = Radius_(radius2=radius2)
1287 with _idllmn6(datum, lat1, lon1, lat2, lon2,
1288 small, wrap, True, radius1=r1, radius2=r2) as t:
1289 _i, d, lat2, lon2, m, n = t
1290 if d is None:
1291 r1 = m2degrees(r1, radius=R_M, lat=lat1)
1292 r2 = m2degrees(r2, radius=R_M, lat=lat2)
1294 def _V2T(x, y, _, **unused): # _ == z unused
1295 return LatLon2Tuple(y, x, name=n)
1297 t = _i(m.Vector3d(lon1, lat1, 0), r1,
1298 m.Vector3d(lon2, lat2, 0), r2, sphere=False,
1299 Vector=_V2T)
1300 else:
1301 def _LL2T(lat, lon, **unused):
1302 return LatLon2Tuple(lat, lon, name=n)
1304 t = _i(m.LatLon(lat1, lon1, datum=d), r1,
1305 m.LatLon(lat2, lon2, datum=d), r2,
1306 LatLon=_LL2T, height=0, wrap=False)
1307 return t
1310def isantipode(lat1, lon1, lat2, lon2, eps=EPS):
1311 '''Check whether two points are I{antipodal}, on diametrically
1312 opposite sides of the earth.
1314 @arg lat1: Latitude of one point (C{degrees}).
1315 @arg lon1: Longitude of one point (C{degrees}).
1316 @arg lat2: Latitude of the other point (C{degrees}).
1317 @arg lon2: Longitude of the other point (C{degrees}).
1318 @kwarg eps: Tolerance for near-equality (C{degrees}).
1320 @return: C{True} if points are antipodal within the
1321 B{C{eps}} tolerance, C{False} otherwise.
1323 @see: Functions L{isantipode_} and L{antipode}.
1324 '''
1325 return (fabs(lat1 + lat2) <= eps and
1326 fabs(lon1 + lon2) <= eps) or _isequalTo(
1327 normal(lat1, lon1), antipode(lat2, lon2), eps)
1330def isantipode_(phi1, lam1, phi2, lam2, eps=EPS):
1331 '''Check whether two points are I{antipodal}, on diametrically
1332 opposite sides of the earth.
1334 @arg phi1: Latitude of one point (C{radians}).
1335 @arg lam1: Longitude of one point (C{radians}).
1336 @arg phi2: Latitude of the other point (C{radians}).
1337 @arg lam2: Longitude of the other point (C{radians}).
1338 @kwarg eps: Tolerance for near-equality (C{radians}).
1340 @return: C{True} if points are antipodal within the
1341 B{C{eps}} tolerance, C{False} otherwise.
1343 @see: Functions L{isantipode} and L{antipode_}.
1344 '''
1345 return (fabs(phi1 + phi2) <= eps and
1346 fabs(lam1 + lam2) <= eps) or _isequalTo_(
1347 normal_(phi1, lam1), antipode_(phi2, lam2), eps)
1350def _isequalTo(p1, p2, eps=EPS):
1351 '''Compare 2 point lat-/lons ignoring C{class}.
1352 '''
1353 return (fabs(p1.lat - p2.lat) <= eps and
1354 fabs(p1.lon - p2.lon) <= eps) if eps else (p1.latlon == p2.latlon)
1357def _isequalTo_(p1, p2, eps=EPS):
1358 '''(INTERNAL) Compare 2 point phi-/lams ignoring C{class}.
1359 '''
1360 return (fabs(p1.phi - p2.phi) <= eps and
1361 fabs(p1.lam - p2.lam) <= eps) if eps else (p1.philam == p2.philam)
1364def isnormal(lat, lon, eps=0):
1365 '''Check whether B{C{lat}} I{and} B{C{lon}} are within their
1366 respective I{normal} range in C{degrees}.
1368 @arg lat: Latitude (C{degrees}).
1369 @arg lon: Longitude (C{degrees}).
1370 @kwarg eps: Optional tolerance C{degrees}).
1372 @return: C{True} if C{(abs(B{lat}) + B{eps}) <= 90} and
1373 C{(abs(B{lon}) + B{eps}) <= 180}, C{False} othwerwise.
1375 @see: Functions L{isnormal_} and L{normal}.
1376 '''
1377 return (_90_0 - fabs(lat)) >= eps and _loneg(fabs(lon)) >= eps
1380def isnormal_(phi, lam, eps=0):
1381 '''Check whether B{C{phi}} I{and} B{C{lam}} are within their
1382 respective I{normal} range in C{radians}.
1384 @arg phi: Latitude (C{radians}).
1385 @arg lam: Longitude (C{radians}).
1386 @kwarg eps: Optional tolerance C{radians}).
1388 @return: C{True} if C{(abs(B{phi}) + B{eps}) <= PI/2} and
1389 C{(abs(B{lam}) + B{eps}) <= PI}, C{False} othwerwise.
1391 @see: Functions L{isnormal} and L{normal_}.
1392 '''
1393 return (PI_2 - fabs(phi)) >= eps and (PI - fabs(lam)) >= eps
1396def latlon2n_xyz(lat, lon, **name):
1397 '''Convert lat-, longitude to C{n-vector} (I{normal} to the
1398 earth's surface) X, Y and Z components.
1400 @arg lat: Latitude (C{degrees}).
1401 @arg lon: Longitude (C{degrees}).
1402 @kwarg name: Optional C{B{name}=NN} (C{str}).
1404 @return: A L{Vector3Tuple}C{(x, y, z)}.
1406 @see: Function L{philam2n_xyz}.
1408 @note: These are C{n-vector} x, y and z components,
1409 I{NOT} geocentric ECEF x, y and z coordinates!
1410 '''
1411 return _2n_xyz(name, *sincos2d_(lat, lon))
1414def _normal2(a, b, n_2, n, n2):
1415 '''(INTERNAL) Helper for C{normal} and C{normal_}.
1416 '''
1417 if fabs(b) > n:
1418 b = remainder(b, n2)
1419 if fabs(a) > n_2:
1420 r = remainder(a, n)
1421 if r != a:
1422 a = -r
1423 b -= n if b > 0 else -n
1424 return float0_(a, b)
1427def normal(lat, lon, **name):
1428 '''Normalize a lat- I{and} longitude pair in C{degrees}.
1430 @arg lat: Latitude (C{degrees}).
1431 @arg lon: Longitude (C{degrees}).
1432 @kwarg name: Optional, overriding C{B{name}="normal"} (C{str}).
1434 @return: L{LatLon2Tuple}C{(lat, lon)} with C{abs(lat) <= 90}
1435 and C{abs(lon) <= 180}.
1437 @see: Functions L{normal_} and L{isnormal}.
1438 '''
1439 return LatLon2Tuple(*_normal2(lat, lon, _90_0, _180_0, _360_0),
1440 name=_name__(name, name__=normal))
1443def normal_(phi, lam, **name):
1444 '''Normalize a lat- I{and} longitude pair in C{radians}.
1446 @arg phi: Latitude (C{radians}).
1447 @arg lam: Longitude (C{radians}).
1448 @kwarg name: Optional, overriding C{B{name}="normal_"} (C{str}).
1450 @return: L{PhiLam2Tuple}C{(phi, lam)} with C{abs(phi) <= PI/2}
1451 and C{abs(lam) <= PI}.
1453 @see: Functions L{normal} and L{isnormal_}.
1454 '''
1455 return PhiLam2Tuple(*_normal2(phi, lam, PI_2, PI, PI2),
1456 name=_name__(name, name__=normal_))
1459def _2n_xyz(name, sa, ca, sb, cb): # name always **name
1460 '''(INTERNAL) Helper for C{latlon2n_xyz} and C{philam2n_xyz}.
1461 '''
1462 # Kenneth Gade eqn 3, but using right-handed
1463 # vector x -> 0°E,0°N, y -> 90°E,0°N, z -> 90°N
1464 return Vector3Tuple(ca * cb, ca * sb, sa, **name)
1467def n_xyz2latlon(x, y, z, **name):
1468 '''Convert C{n-vector} components to lat- and longitude in C{degrees}.
1470 @arg x: X component (C{scalar}).
1471 @arg y: Y component (C{scalar}).
1472 @arg z: Z component (C{scalar}).
1473 @kwarg name: Optional C{B{name}=NN} (C{str}).
1475 @return: A L{LatLon2Tuple}C{(lat, lon)}.
1477 @see: Function L{n_xyz2philam}.
1478 '''
1479 return LatLon2Tuple(atan2d(z, hypot(x, y)), atan2d(y, x), **name)
1482def n_xyz2philam(x, y, z, **name):
1483 '''Convert C{n-vector} components to lat- and longitude in C{radians}.
1485 @arg x: X component (C{scalar}).
1486 @arg y: Y component (C{scalar}).
1487 @arg z: Z component (C{scalar}).
1488 @kwarg name: Optional C{B{name}=NN} (C{str}).
1490 @return: A L{PhiLam2Tuple}C{(phi, lam)}.
1492 @see: Function L{n_xyz2latlon}.
1493 '''
1494 return PhiLam2Tuple(atan2(z, hypot(x, y)), atan2(y, x), **name)
1497def _opposes(d, m, n, n2):
1498 '''(INTERNAL) Helper for C{opposing} and C{opposing_}.
1499 '''
1500 d = d % n2 # -20 % 360 == 340, -1 % PI2 == PI2 - 1
1501 return False if d < m or d > (n2 - m) else (
1502 True if (n - m) < d < (n + m) else None)
1505def opposing(bearing1, bearing2, margin=_90_0):
1506 '''Compare the direction of two bearings given in C{degrees}.
1508 @arg bearing1: First bearing (compass C{degrees}).
1509 @arg bearing2: Second bearing (compass C{degrees}).
1510 @kwarg margin: Optional, interior angle bracket (C{degrees}).
1512 @return: C{True} if both bearings point in opposite, C{False} if
1513 in similar or C{None} if in I{perpendicular} directions.
1515 @see: Function L{opposing_}.
1516 '''
1517 m = Degrees_(margin=margin, low=EPS0, high=_90_0)
1518 return _opposes(bearing2 - bearing1, m, _180_0, _360_0)
1521def opposing_(radians1, radians2, margin=PI_2):
1522 '''Compare the direction of two bearings given in C{radians}.
1524 @arg radians1: First bearing (C{radians}).
1525 @arg radians2: Second bearing (C{radians}).
1526 @kwarg margin: Optional, interior angle bracket (C{radians}).
1528 @return: C{True} if both bearings point in opposite, C{False} if
1529 in similar or C{None} if in perpendicular directions.
1531 @see: Function L{opposing}.
1532 '''
1533 m = Radians_(margin=margin, low=EPS0, high=PI_2)
1534 return _opposes(radians2 - radians1, m, PI, PI2)
1537def philam2n_xyz(phi, lam, **name):
1538 '''Convert lat-, longitude to C{n-vector} (I{normal} to the
1539 earth's surface) X, Y and Z components.
1541 @arg phi: Latitude (C{radians}).
1542 @arg lam: Longitude (C{radians}).
1543 @kwarg name: Optional name (C{str}).
1545 @return: A L{Vector3Tuple}C{(x, y, z)}.
1547 @see: Function L{latlon2n_xyz}.
1549 @note: These are C{n-vector} x, y and z components,
1550 I{NOT} geocentric ECEF x, y and z coordinates!
1551 '''
1552 return _2n_xyz(name, *sincos2_(phi, lam))
1555def _Propy(func, nargs, kwds):
1556 '''(INTERNAL) Helper for the C{frechet.[-]Frechet**} and
1557 C{hausdorff.[-]Hausdorff*} classes.
1558 '''
1559 try:
1560 _xcallable(distance=func)
1561 # assert _args_kwds_count2(func)[0] == nargs + int(ismethod(func))
1562 _ = func(*_0_0s(nargs), **kwds)
1563 except Exception as x:
1564 t = unstr(func, **kwds)
1565 raise _TypeError(t, cause=x)
1566 return func
1569def _radical2(d, r1, r2, **name): # in .ellipsoidalBaseDI, .sphericalTrigonometry, .vector3d
1570 # (INTERNAL) See C{radical2} below
1571 # assert d > EPS0
1572 r = fsumf_(_1_0, (r1 / d)**2, -(r2 / d)**2) * _0_5
1573 n = _name__(name, name__=radical2)
1574 return Radical2Tuple(max(_0_0, min(_1_0, r)), r * d, name=n)
1577def radical2(distance, radius1, radius2, **name):
1578 '''Compute the I{radical ratio} and I{radical line} of two
1579 U{intersecting circles<https://MathWorld.Wolfram.com/
1580 Circle-CircleIntersection.html>}.
1582 The I{radical line} is perpendicular to the axis thru the
1583 centers of the circles at C{(0, 0)} and C{(B{distance}, 0)}.
1585 @arg distance: Distance between the circle centers (C{scalar}).
1586 @arg radius1: Radius of the first circle (C{scalar}).
1587 @arg radius2: Radius of the second circle (C{scalar}).
1588 @kwarg name: Optional C{B{name}=NN} (C{str}).
1590 @return: A L{Radical2Tuple}C{(ratio, xline)} where C{0.0 <=
1591 ratio <= 1.0} and C{xline} is along the B{C{distance}}.
1593 @raise IntersectionError: The B{C{distance}} exceeds the sum
1594 of B{C{radius1}} and B{C{radius2}}.
1596 @raise UnitError: Invalid B{C{distance}}, B{C{radius1}} or
1597 B{C{radius2}}.
1599 @see: U{Circle-Circle Intersection
1600 <https://MathWorld.Wolfram.com/Circle-CircleIntersection.html>}.
1601 '''
1602 d = Distance_(distance, low=_0_0)
1603 r1 = Radius_(radius1=radius1)
1604 r2 = Radius_(radius2=radius2)
1605 if d > (r1 + r2):
1606 raise IntersectionError(distance=d, radius1=r1, radius2=r2,
1607 txt=_too_(_distant_))
1608 return _radical2(d, r1, r2, **name) if d > EPS0 else \
1609 Radical2Tuple(_0_5, _0_0, **name)
1612class Radical2Tuple(_NamedTuple):
1613 '''2-Tuple C{(ratio, xline)} of the I{radical} C{ratio} and
1614 I{radical} C{xline}, both C{scalar} and C{0.0 <= ratio <= 1.0}
1615 '''
1616 _Names_ = (_ratio_, _xline_)
1617 _Units_ = ( Scalar, Scalar)
1620def _radistance(inst):
1621 '''(INTERNAL) Helper for the L{frechet._FrechetMeterRadians}
1622 and L{hausdorff._HausdorffMeterRedians} classes.
1623 '''
1624 wrap_, kwds_ = _xkwds_pop2(inst._kwds, wrap=False)
1625 func_ = inst._func_
1626 try: # calling lower-overhead C{func_}
1627 func_(0, _0_25, _0_5, **kwds_)
1628 wrap_ = _Wrap._philamop(wrap_)
1629 except TypeError:
1630 return inst.distance
1632 def _philam(p):
1633 try:
1634 return p.phi, p.lam
1635 except AttributeError: # no .phi or .lam
1636 return radians(p.lat), radians(p.lon)
1638 def _func_wrap(point1, point2):
1639 phi1, lam1 = wrap_(*_philam(point1))
1640 phi2, lam2 = wrap_(*_philam(point2))
1641 return func_(phi2, phi1, lam2 - lam1, **kwds_)
1643 inst._units = inst._units_
1644 return _func_wrap
1647def _scale_deg(lat1, lat2): # degrees
1648 # scale factor cos(mean of lats) for delta lon
1649 m = fabs(lat1 + lat2) * _0_5
1650 return cos(radians(m)) if m < 90 else _0_0
1653def _scale_rad(phi1, phi2): # radians, by .frechet, .hausdorff, .heights
1654 # scale factor cos(mean of phis) for delta lam
1655 m = fabs(phi1 + phi2) * _0_5
1656 return cos(m) if m < PI_2 else _0_0
1659def _sincosa6(phi2, phi1, lam21): # [4] in cosineLaw
1660 '''(INTERNAL) C{sin}es, C{cos}ines and C{acos}ine.
1661 '''
1662 s2, c2, s1, c1, _, c21 = sincos2_(phi2, phi1, lam21)
1663 return s2, c2, s1, c1, acos1(s1 * s2 + c1 * c2 * c21), c21
1666def thomas(lat1, lon1, lat2, lon2, datum=_WGS84, wrap=False):
1667 '''Compute the distance between two (ellipsoidal) points using
1668 U{Thomas'<https://apps.DTIC.mil/dtic/tr/fulltext/u2/703541.pdf>}
1669 formula.
1671 @arg lat1: Start latitude (C{degrees}).
1672 @arg lon1: Start longitude (C{degrees}).
1673 @arg lat2: End latitude (C{degrees}).
1674 @arg lon2: End longitude (C{degrees}).
1675 @kwarg datum: Datum (L{Datum}) or ellipsoid (L{Ellipsoid},
1676 L{Ellipsoid2} or L{a_f2Tuple}) to use.
1677 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll
1678 B{C{lat2}} and B{C{lon2}} (C{bool}).
1680 @return: Distance (C{meter}, same units as the B{C{datum}}'s
1681 ellipsoid axes).
1683 @raise TypeError: Invalid B{C{datum}}.
1685 @see: Functions L{thomas_}, L{cosineAndoyerLambert}, L{cosineForsytheAndoyerLambert},
1686 L{cosineLaw}, L{equirectangular}, L{euclidean}, L{flatLocal}/L{hubeny},
1687 L{flatPolar}, L{haversine}, L{vincentys} and method L{Ellipsoid.distance2}.
1688 '''
1689 return _dE(thomas_, datum, wrap, lat1, lon1, lat2, lon2)
1692def thomas_(phi2, phi1, lam21, datum=_WGS84):
1693 '''Compute the I{angular} distance between two (ellipsoidal) points using
1694 U{Thomas'<https://apps.DTIC.mil/dtic/tr/fulltext/u2/703541.pdf>}
1695 formula.
1697 @arg phi2: End latitude (C{radians}).
1698 @arg phi1: Start latitude (C{radians}).
1699 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
1700 @kwarg datum: Datum or ellipsoid to use (L{Datum}, L{Ellipsoid},
1701 L{Ellipsoid2} or L{a_f2Tuple}).
1703 @return: Angular distance (C{radians}).
1705 @raise TypeError: Invalid B{C{datum}}.
1707 @see: Functions L{thomas}, L{cosineAndoyerLambert_},
1708 L{cosineForsytheAndoyerLambert_}, L{cosineLaw_},
1709 L{euclidean_}, L{flatLocal_}/L{hubeny_}, L{flatPolar_},
1710 L{haversine_} and L{vincentys_} and U{Geodesy-PHP
1711 <https://GitHub.com/jtejido/geodesy-php/blob/master/src/Geodesy/
1712 Distance/ThomasFormula.php>}.
1713 '''
1714 s2, c2, s1, c1, r, _ = _sincosa6(phi2, phi1, lam21)
1715 if r and isnon0(c1) and isnon0(c2):
1716 E = _ellipsoidal(datum, thomas_)
1717 if E.f:
1718 r1 = atan2(E.b_a * s1, c1)
1719 r2 = atan2(E.b_a * s2, c2)
1721 j = (r2 + r1) * _0_5
1722 k = (r2 - r1) * _0_5
1723 sj, cj, sk, ck, h, _ = sincos2_(j, k, lam21 * _0_5)
1725 h = fsumf_(sk**2, (ck * h)**2, -(sj * h)**2)
1726 u = _1_0 - h
1727 if isnon0(u) and isnon0(h):
1728 r = atan(sqrt0(h / u)) * 2 # == acos(1 - 2 * h)
1729 sr, cr = sincos2(r)
1730 if isnon0(sr):
1731 u = 2 * (sj * ck)**2 / u
1732 h = 2 * (sk * cj)**2 / h
1733 x = u + h
1734 y = u - h
1736 s = r / sr
1737 e = 4 * s**2
1738 d = 2 * cr
1739 a = e * d
1740 b = 2 * r
1741 c = s - (a - d) * _0_5
1742 f = E.f * _0_25
1744 t = fsumf_(a * x, -b * y, c * x**2, -d * y**2, e * x * y)
1745 r -= fsumf_(s * x, -y, -t * f * _0_25) * f * sr
1746 return r
1749def vincentys(lat1, lon1, lat2, lon2, radius=R_M, wrap=False):
1750 '''Compute the distance between two (spherical) points using
1751 U{Vincenty's<https://WikiPedia.org/wiki/Great-circle_distance>}
1752 spherical formula.
1754 @arg lat1: Start latitude (C{degrees}).
1755 @arg lon1: Start longitude (C{degrees}).
1756 @arg lat2: End latitude (C{degrees}).
1757 @arg lon2: End longitude (C{degrees}).
1758 @kwarg radius: Mean earth radius (C{meter}), datum (L{Datum})
1759 or ellipsoid (L{Ellipsoid}, L{Ellipsoid2} or
1760 L{a_f2Tuple}) to use.
1761 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll
1762 B{C{lat2}} and B{C{lon2}} (C{bool}).
1764 @return: Distance (C{meter}, same units as B{C{radius}}).
1766 @raise UnitError: Invalid B{C{radius}}.
1768 @see: Functions L{vincentys_}, L{cosineAndoyerLambert},
1769 L{cosineForsytheAndoyerLambert},L{cosineLaw}, L{equirectangular},
1770 L{euclidean}, L{flatLocal}/L{hubeny}, L{flatPolar},
1771 L{haversine} and L{thomas} and methods L{Ellipsoid.distance2},
1772 C{LatLon.distanceTo*} and C{LatLon.equirectangularTo}.
1774 @note: See note at function L{vincentys_}.
1775 '''
1776 return _dS(vincentys_, radius, wrap, lat1, lon1, lat2, lon2)
1779def vincentys_(phi2, phi1, lam21):
1780 '''Compute the I{angular} distance between two (spherical) points using
1781 U{Vincenty's<https://WikiPedia.org/wiki/Great-circle_distance>}
1782 spherical formula.
1784 @arg phi2: End latitude (C{radians}).
1785 @arg phi1: Start latitude (C{radians}).
1786 @arg lam21: Longitudinal delta, M{end-start} (C{radians}).
1788 @return: Angular distance (C{radians}).
1790 @see: Functions L{vincentys}, L{cosineAndoyerLambert_},
1791 L{cosineForsytheAndoyerLambert_}, L{cosineLaw_},
1792 L{euclidean_}, L{flatLocal_}/L{hubeny_}, L{flatPolar_},
1793 L{haversine_} and L{thomas_}.
1795 @note: Functions L{vincentys_}, L{haversine_} and L{cosineLaw_}
1796 produce equivalent results, but L{vincentys_} is suitable
1797 for antipodal points and slightly more expensive (M{3 cos,
1798 3 sin, 1 hypot, 1 atan2, 6 mul, 2 add}) than L{haversine_}
1799 (M{2 cos, 2 sin, 2 sqrt, 1 atan2, 5 mul, 1 add}) and
1800 L{cosineLaw_} (M{3 cos, 3 sin, 1 acos, 3 mul, 1 add}).
1801 '''
1802 s1, c1, s2, c2, s21, c21 = sincos2_(phi1, phi2, lam21)
1804 c = c2 * c21
1805 x = s1 * s2 + c1 * c
1806 y = c1 * s2 - s1 * c
1807 return atan2(hypot(c2 * s21, y), x)
1809# **) MIT License
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