1

2# -*- coding: utf-8 -*-

3

4 u'''Wrapper around Python classes C{geodesic.Geodesic} and C{geodesicline.GeodesicLine} from

5 I{Karney}'s Python package U{geographiclib<https://PyPI.org/project/geographiclib>}, provided

6 that package is installed.

7

8 The I{wrapped} class methods return a L{GDict} instance offering access to the C{dict} items

9 either by C{key} or by C{attribute} name.

10

11 With env variable C{PYGEODESY_GEOGRAPHICLIB} left undefined or set to C{"2"}, this module,

12 L{pygeodesy.geodesicx} and L{pygeodesy.karney} will use U{GeographicLib 2.0

13<https://GeographicLib.SourceForge.io/C++/doc/>} transcoding, otherwise C{1.52} or older.

14'''

15

16 from pygeodesy.basics import _copysign, _xinstanceof

17 from pygeodesy.constants import EPS, NAN, _EPSqrt as _TOL, _0_5

18 from pygeodesy.datums import _earth_datum, _WGS84, _EWGS84

19# from pygeodesy.dms import F_D # from .latlonBase

20# from pygeodesy.ellipsoids import _EWGS84 # from .datums

21 from pygeodesy.errors import IntersectionError, GeodesicError

22 from pygeodesy.interns import NN, _DOT_, _dunder_nameof, _SPACE_, \

23 _to_, _too_,_under

24 from pygeodesy.karney import _atan2d, Caps, Direct9Tuple, GDict, \

25 _kWrapped, Inverse10Tuple

26 from pygeodesy.latlonBase import LatLonBase as _LLB, F_D, Radius_

27 from pygeodesy.lazily import _ALL_LAZY, _ALL_MODS as _MODS

28 from pygeodesy.named import callername, classname

29 from pygeodesy.namedTuples import Destination3Tuple, Distance3Tuple

30 from pygeodesy.props import Property, Property_RO, property_RO

31 from pygeodesy.streprs import Fmt, unstr

32# from pygeodesy.units import Radius_ # from .latlonBase

33 from pygeodesy.utily import _unrollon, _Wrap, wrap360, fabs # PYCHOK used!

34

35 from contextlib import contextmanager

36# from math import fabs # from .utily

37

38__all__ = _ALL_LAZY.geodesicw

39__version__ = '23.12.09'

40

41_plumb_ = 'plumb'

42_TRIPS = 129

43

44

45 class _gWrapped(_kWrapped):

46 ''''(INTERNAL) Wrapper for some of I{Karney}'s U{geographiclib

47 <https://PyPI.org/project/geographiclib>} classes.

48 '''

49

50 @Property_RO # MCCABE 24

51 def Geodesic(self):

52 '''Get the I{wrapped} C{geodesic.Geodesic} class from I{Karney}'s Python

53 U{geographiclib<https://GitHub.com/geographiclib/geographiclib-python>},

54 provided the latter is installed.

55 '''

56 _Geodesic = self.geographiclib.Geodesic

57 # assert Caps._STD == _Geodesic.STANDARD

58

59 class Geodesic(_Geodesic):

60 '''I{Wrapper} for I{Karney}'s Python U{geodesic.Geodesic

61 <https://PyPI.org/project/geographiclib>} class.

62 '''

63 _datum = _WGS84

64 _debug = 0 # like .geodesicx.bases._GeodesicBase

65 LINE_OFF = 0 # in .azimuthal._GnomonicBase and .css.CassiniSoldner

66

67 def __init__(self, a_ellipsoid=_EWGS84, f=None, name=NN): # PYCHOK signature

68 '''New I{wrapped} C{geodesic.Geodesic} instance.

69

70 @arg a_ellipsoid: An ellipsoid (L{Ellipsoid}) or datum (L{Datum})

71 or the equatorial radius I{a} of the ellipsoid (C{meter}).

72 @arg f: The flattening of the ellipsoid (C{scalar}), ignored if

73 B{C{a_ellipsoid}) is not specified as C{scalar}.

74 @kwarg name: Optional ellipsoid name (C{str}), ignored like B{C{f}}.

75 '''

76 _earth_datum(self, a_ellipsoid, f=f, name=name) # raiser=NN

77 with _wargs(self, *self.ellipsoid.a_f, name=name) as args:

78 _Geodesic.__init__(self, *args)

79

80 def ArcDirect(self, lat1, lon1, azi1, a12, outmask=Caps._STD):

81 '''Return the C{_Geodesic.ArcDirect} result as L{GDict}.

82 '''

83 with _wargs(self, lat1, lon1, azi1, a12, outmask) as args:

84 d = _Geodesic.ArcDirect(self, *args)

85 return GDict(d)

86

87 def ArcDirectLine(self, lat1, lon1, azi1, a12, caps=Caps._STD_LINE):

88 '''Return the C{_Geodesic.ArcDirectLine} as I{wrapped} C{GeodesicLine}.

89 '''

90 return self._GenDirectLine(lat1, lon1, azi1, True, a12, caps)

91

92 Area = _Geodesic.Polygon # like GeodesicExact.Area

93

94 @property_RO

95 def datum(self):

96 '''Get this geodesic's datum (C{Datum}).

97 '''

98 return self._datum

99

100 @Property

101 def debug(self):

102 '''Get the C{debug} option (C{bool}).

103 '''

104 return bool(self._debug)

105

106 @debug.setter # PYCHOK setter!

107 def debug(self, debug):

108 '''Set the C{debug} option (C{bool}) to include more

109 details in L{GDict} results.

110 '''

111 self._debug = Caps._DEBUG_ALL if debug else 0

112

113 def Direct(self, lat1, lon1, azi1, s12=0, outmask=Caps._STD):

114 '''Return the C{_Geodesic.Direct} result as L{GDict}.

115 '''

116 with _wargs(self, lat1, lon1, azi1, s12, outmask) as args:

117 d = _Geodesic.Direct(self, *args)

118 return GDict(d)

119

120 def Direct3(self, lat1, lon1, azi1, s12): # PYCHOK outmask

121 '''Return the destination lat, lon and reverse azimuth

122 in C{degrees} as L{Destination3Tuple}.

123 '''

124 d = self.Direct(lat1, lon1, azi1, s12, outmask=Caps._DIRECT3)

125 return Destination3Tuple(d.lat2, d.lon2, d.azi2)

126

127 def _DirectLine(self, ll1, azi12, s12=0, **caps_name):

128 '''(INTERNAL) Short-cut version.

129 '''

130 return self.DirectLine(ll1.lat, ll1.lon, azi12, s12, **caps_name)

131

132 def DirectLine(self, lat1, lon1, azi1, s12, caps=Caps._STD_LINE):

133 '''Return the C{_Geodesic.DirectLine} as I{wrapped} C{GeodesicLine}.

134 '''

135 return self._GenDirectLine(lat1, lon1, azi1, False, s12, caps)

136

137 @Property_RO

138 def ellipsoid(self):

139 '''Get this geodesic's ellipsoid (C{Ellipsoid}).

140 '''

141 return self.datum.ellipsoid

142

143 @property_RO

144 def f1(self): # in .css.CassiniSoldner.reset

145 '''Get the geodesic's ellipsoid's I{1 - flattening} (C{float}).

146 '''

147 return getattr(self, _under(Geodesic.f1.name), self.ellipsoid.f1)

148

149 def _GDictDirect(self, lat, lon, azi, arcmode, s12_a12, outmask=Caps._STD):

150 '''(INTERNAL) Get C{_Geodesic._GenDirect} result as C{GDict}.

151 '''

152 with _wargs(self, lat, lon, azi, arcmode, s12_a12, outmask) as args:

153 t = _Geodesic._GenDirect(self, *args)

154 return Direct9Tuple(t).toGDict() # *t

155

156 def _GDictInverse(self, lat1, lon1, lat2, lon2, outmask=Caps._STD):

157 '''(INTERNAL) Get C{_Geodesic._GenInverse} result as L{Inverse10Tuple}.

158 '''

159 with _wargs(self, lat1, lon1, lat2, lon2, outmask) as args:

160 t = _Geodesic._GenInverse(self, *args)

161 return Inverse10Tuple(t).toGDict(lon1=lon1, lon2=lon2) # *t

162

163 def _GenDirectLine(self, lat1, lon1, azi1, arcmode, s12_a12, *caps):

164 '''(INTERNAL) Invoked by C{_Geodesic.DirectLine} and C{-.ArcDirectLine},

165 returning the result as a I{wrapped} C{GeodesicLine}.

166 '''

167 with _wargs(self, lat1, lon1, azi1, arcmode, s12_a12, *caps) as args:

168 t = _Geodesic._GenDirectLine(self, *args)

169 return self._Line13(t)

170

171 def _Inverse(self, ll1, ll2, wrap, **outmask):

172 '''(INTERNAL) Short-cut version, see .ellipsoidalBaseDI.intersecant2.

173 '''

174 if wrap:

175 ll2 = _unrollon(ll1, _Wrap.point(ll2))

176 return self.Inverse(ll1.lat, ll1.lon, ll2.lat, ll2.lon, **outmask)

177

178 def Inverse(self, lat1, lon1, lat2, lon2, outmask=Caps._STD):

179 '''Return the C{_Geodesic.Inverse} result as L{GDict}.

180 '''

181 with _wargs(self, lat1, lon1, lat2, lon2, outmask) as args:

182 d = _Geodesic.Inverse(self, *args)

183 return GDict(d)

184

185 def Inverse1(self, lat1, lon1, lat2, lon2, wrap=False):

186 '''Return the non-negative, I{angular} distance in C{degrees}.

187

188 @kwarg wrap: If C{True}, wrap or I{normalize} and unroll

189 B{C{lat2}} and BC{lon2}} (C{bool}).

190 '''

191 # see .FrechetKarney.distance, .HausdorffKarney._distance

192 # and .HeightIDWkarney._distances

193 if wrap:

194 _, lat2, lon2 = _Wrap.latlon3(lat1, lat2, lon2, True) # _Geodesic.LONG_UNROLL

195 r = self.Inverse(lat1, lon1, lat2, lon2)

196 # XXX _Geodesic.DISTANCE needed for 'a12'?

197 return fabs(r.a12)

198

199 def Inverse3(self, lat1, lon1, lat2, lon2): # PYCHOK outmask

200 '''Return the distance in C{meter} and the forward and reverse

201 azimuths in C{degrees} as L{Distance3Tuple}.

202 '''

203 r = self.Inverse(lat1, lon1, lat2, lon2, outmask=Caps._INVERSE3)

204 return Distance3Tuple(r.s12, wrap360(r.azi1), wrap360(r.azi2))

205

206 def _InverseLine(self, ll1, ll2, wrap, **caps_name):

207 '''(INTERNAL) Short-cut version.

208 '''

209 if wrap:

210 ll2 = _unrollon(ll1, _Wrap.point(ll2))

211 return self.InverseLine(ll1.lat, ll1.lon, ll2.lat, ll2.lon, **caps_name)

212

213 def InverseLine(self, lat1, lon1, lat2, lon2, caps=Caps._STD_LINE):

214 '''Return the C{_Geodesic.InverseLine} as I{wrapped} C{GeodesicLine}.

215 '''

216 with _wargs(self, lat1, lon1, lat2, lon2, caps) as args:

217 t = _Geodesic.InverseLine(self, *args)

218 return self._Line13(t)

219

220 def Line(self, lat1, lon1, azi1, caps=Caps._STD_LINE):

221 '''Set up a I{wrapped} C{GeodesicLine} to compute several points

222 along a single, I{wrapped} (this) geodesic.

223 '''

224 return _wrapped.GeodesicLine(self, lat1, lon1, azi1, caps=caps)

225

226 def _Line13(self, t):

227 '''(INTERNAL) Wrap C{_GeodesicLine}, add distance and arc length

228 to reference point 3.

229 '''

230 gl = _wrapped.GeodesicLine(self, t.lat1, t.lon1, t.azi1, caps=t.caps,

231 salp1=t.salp1, calp1=t.calp1)

232 gl.a13, gl.s13 = t.a13, t.s13

233 return gl

234

235# Polygon = _Geodesic.Polygon

236

237 # Geodesic.ArcDirect.__doc__ = _Geodesic.ArcDirect.__doc__

238 # Geodesic.Direct.__doc__ = _Geodesic.Direct.__doc__

239 # Geodesic.Inverse.__doc__ = _Geodesic.Inverse.__doc__

240 # Geodesic.InverseLine.__doc__ = _Geodesic.InverseLinr.__doc__

241 # Geodesic.Line.__doc__ = _Geodesic.Line.__doc__

242 return Geodesic

243

244 @Property_RO # MCCABE 16

245 def GeodesicLine(self):

246 '''Get the I{wrapped} C{geodesicline.GeodesicLine} class from I{Karney}'s

247 Python U{geographiclib<https://GitHub.com/geographiclib/geographiclib-python>},

248 provided the latter is installed.

249 '''

250 _GeodesicLine = self.geographiclib.GeodesicLine

251

252 class GeodesicLine(_GeodesicLine):

253 '''I{Wrapper} for I{Karney}'s Python U{geodesicline.GeodesicLine

254 <https://PyPI.org/project/geographiclib>} class.

255 '''

256 _geodesic = None

257

258 def __init__(self, geodesic, lat1, lon1, azi1, **caps_): # salp1=NAN, calp1=NAN

259 '''New I{wrapped} C{geodesicline.GeodesicLine} instance.

260

261 @arg geodesic: A I{wrapped} C{Geodesic} instance.

262 @arg lat1: Latitude of the first points (C{degrees}).

263 @arg lon1: Longitude of the first points (C{degrees}).

264 @arg azi1: Azimuth at the first points (compass C{degrees360}).

265 @kwarg caps_: Optional, bit-or'ed combination of L{Caps} values

266 specifying the capabilities the C{GeodesicLine}

267 instance should possess (plus optional keyword

268 arguments C{salp1=NAN} and C{calp1=NAN}).

269 '''

270 _xinstanceof(_wrapped.Geodesic, geodesic=geodesic)

271 with _wargs(self, geodesic, lat1, lon1, azi1, **caps_) as args:

272 _GeodesicLine.__init__(self, *args, **caps_)

273 self._geodesic = geodesic

274

275 @Property_RO

276 def a1(self):

277 '''Get the I{equatorial arc} (C{degrees}), the arc length between

278 the northward equatorial crossing and point C{(lat1, lon1)}.

279

280 @see: U{EquatorialArc<https://GeographicLib.SourceForge.io/

281 C++/doc/classGeographicLib_1_1GeodesicLine.html>}

282 '''

283 try:

284 return _atan2d(self._ssig1, self._csig1)

285 except AttributeError:

286 return NAN # see .geodesicx.gxline._GeodesicLineExact

287

288 equatorarc = a1

289

290 def Arc(self):

291 '''Return the angular distance to point 3 (C{degrees} or C{NAN}).

292 '''

293 return self.a13

294

295 def ArcPosition(self, a12, outmask=Caps._STD):

296 '''Return the position at C{B{a12} degrees} on this line.

297

298 @arg a12: Angular distance from this line's first point

299 (C{degrees}).

300

301 @see: Method L{Position} for further details.

302 '''

303 with _wargs(self, a12, outmask) as args:

304 d = _GeodesicLine.ArcPosition(self, *args)

305 return GDict(d)

306

307 @Property_RO

308 def azi0(self): # see .css.CassiniSoldner.forward4

309 '''Get the I{equatorial azimuth} (C{degrees}), the azimuth of the

310 geodesic line as it crosses the equator in a northward direction.

311

312 @see: U{EquatorialAzimuth<https://GeographicLib.SourceForge.io/

313 C++/doc/classGeographicLib_1_1GeodesicLine.html>}

314 '''

315 try:

316 return _atan2d(self._salp0, self._calp0)

317 except AttributeError:

318 return NAN # see .geodesicx.gxline._GeodesicLineExact

319

320 equatorazimuth = azi0

321

322 def Distance(self):

323 '''Return the distance to reference point 3 (C{meter} or C{NAN}).

324 '''

325 return self.s13

326

327 @property_RO

328 def geodesic(self):

329 '''Get the I{wrapped} geodesic (L{Geodesic}).

330 '''

331 return self._geodesic

332

333 def Intersecant2(self, lat0, lon0, radius, tol=_TOL):

334 '''Compute the intersection(s) of this geodesic line and a circle.

335

336 @arg lat0: Latitude of the circle center (C{degrees}).

337 @arg lon0: Longitude of the circle center (C{degrees}).

338 @arg radius: Radius of the circle (C{meter}, conventionally).

339 @kwarg tol: Convergence tolerance (C{scalar}).

340

341 @return: 2-Tuple C{(P, Q)} with both intersections (representing a

342 geodesic chord), each a L{GDict} from method L{Position}

343 extended to 14 items by C{lon0, lat0, azi0, a02, s02, at}

344 with the circle center C{lat0}, C{lon0}, azimuth C{azi0} at,

345 distance C{a02} in C{degrees} and C{s02} in C{meter} along

346 the geodesic from the circle center to the intersection

347 C{lat2}, C{lon2} and the angle C{at} between the geodesic

348 and this line at the intersection. The I{geodesic} azimuth

349 at the intersection is C{(at + azi2)}. If this line is

350 tangential to the circle, both intersections are the same

351 L{GDict} instance.

352

353 @raise IntersectionError: The circle and this geodesic line do not

354 intersect.

355

356 @raise UnitError: Invalid B{C{radius}}.

357 '''

358 return _Intersecant2(self, lat0, lon0, radius, tol=tol)

359

360 def PlumbTo(self, lat0, lon0, est=None, tol=_TOL):

361 '''Compute the I{perpendicular} intersection of this geodesic line

362 with a geodesic from the given point.

363

364 @arg lat0: Latitude of the point (C{degrees}).

365 @arg lon0: Longitude of the point (C{degrees}).

366 @kwarg est: Optional, initial estimate for the distance C{s12} of

367 the intersection I{along} this geodesic line (C{meter}).

368 @kwarg tol: Convergence tolerance (C(meter)).

369

370 @return: The intersection point on this geodesic line, a L{GDict}

371 from method L{Position} extended to 14 items C{lat1, lon1,

372 azi1, lat2, lon2, azi2, a12, s12, lat0, lon0, azi0, a02,

373 s02, at} with C{a02} and C{s02} the distance in C{degrees}

374 and C{meter} from the given point C{lat0, lon0} to the

375 intersection C{lat2, lon2}, azimuth C{azi0} at the given

376 point and the (perpendicular) angle C{at} between the

377 geodesic and this line at the intersection point. The

378 geodesic azimuth at the intersection is C{(at + azi2)}.

379 See method L{Position} for further details.

380

381 @see: Methods C{Intersecant2}, C{Intersection} and C{Position}.

382 '''

383 return _PlumbTo(self, lat0, lon0, est=est, tol=tol)

384

385 def Position(self, s12, outmask=Caps._STD):

386 '''Return the position at distance C{B{s12} meter} on this line.

387

388 @arg s12: Distance from this line's first point (C{meter}).

389 @kwarg outmask: Bit-or'ed combination of L{Caps} values specifying

390 the quantities to be returned.

391

392 @return: A L{GDict} with up to 12 items C{lat1, lon1, azi1, lat2,

393 lon2, azi2, m12, a12, s12, M12, M21, S12} with C{lat1},

394 C{lon1}, C{azi1} and arc length C{a12} always included,

395 except when C{a12=NAN}.

396 '''

397 with _wargs(self, s12, outmask) as args:

398 d = _GeodesicLine.Position(self, *args)

399 return GDict(d)

400

401 # GeodesicLine.ArcPosition.__doc__ = _GeodesicLine.ArcPosition.__doc__

402 # GeodesicLine.Position.__doc__ = _GeodesicLine.Position.__doc__

403 return GeodesicLine

404

405 @Property_RO

406 def Geodesic_WGS84(self):

407 '''Get the I{wrapped} C{Geodesic(WGS84)} singleton, provided the

408 U{geographiclib<https://PyPI.org/project/geographiclib>} package

409 is installed, otherwise an C{ImportError}.

410 '''

411 return _EWGS84.geodesic

412

413_wrapped = _gWrapped() # PYCHOK singleton, .ellipsoids, .test/base.py

414

415

416 def Geodesic(a_ellipsoid, f=None, name=NN):

417 '''Return a I{wrapped} C{geodesic.Geodesic} instance from I{Karney}'s

418 Python U{geographiclib<https://PyPI.org/project/geographiclib>},

419 provide the latter is installed, otherwise an C{ImportError}.

420

421 @arg a_ellipsoid: An ellipsoid (L{Ellipsoid}) or datum (L{Datum})

422 or the equatorial radius I{a} of the ellipsoid (C{meter}).

423 @arg f: The flattening of the ellipsoid (C{scalar}), ignored if

424 B{C{a_ellipsoid}}) is not specified as C{meter}.

425 @kwarg name: Optional ellipsoid name (C{str}), ignored like B{C{f}}.

426 '''

427 return _wrapped.Geodesic(a_ellipsoid, f=f, name=name)

428

429

430 def GeodesicLine(geodesic, lat1, lon1, azi1, caps=Caps._STD_LINE):

431 '''Return a I{wrapped} C{geodesicline.GeodesicLine} instance from I{Karney}'s

432 Python U{geographiclib<https://PyPI.org/project/geographiclib>}, provided

433 the latter is installed, otherwise an C{ImportError}.

434

435 @arg geodesic: A I{wrapped} L{Geodesic} instance.

436 @arg lat1: Latitude of the first points (C{degrees}).

437 @arg lon1: Longitude of the first points (C{degrees}).

438 @arg azi1: Azimuth at the first points (compass C{degrees360}).

439 @kwarg caps: Optional, bit-or'ed combination of L{Caps} values

440 specifying the capabilities the C{GeodesicLine}

441 instance should possess, i.e., which quantities can

442 be returned by calls to C{GeodesicLine.Position}

443 and C{GeodesicLine.ArcPosition}.

444 '''

445 return _wrapped.GeodesicLine(geodesic, lat1, lon1, azi1, caps=caps)

446

447

448 def Geodesic_WGS84():

449 '''Get the I{wrapped} L{Geodesic}C{(WGS84)} singleton, provided

450 U{geographiclib<https://PyPI.org/project/geographiclib>} is

451 installed, otherwise an C{ImportError}.

452 '''

453 return _wrapped.Geodesic_WGS84

454

455

456 class _wargs(object): # see also .formy._idllmn6, .latlonBase._toCartesian3, .vector2d._numpy

457 '''(INTERNAL) C{geographiclib} caller and exception mapper.

458 '''

459 @contextmanager # <https://www.Python.org/dev/peps/pep-0343/> Examples

460 def __call__(self, inst, *args, **kwds):

461 '''(INTERNAL) Yield C{tuple(B{args})} with any errors raised

462 as L{GeodesicError} embellished with all B{C{kwds}}.

463 '''

464 try:

465 yield args

466 except (AttributeError, TypeError, ValueError) as x:

467 n = _DOT_(classname(inst), callername(up=3, underOK=True))

468 raise GeodesicError(unstr(n, *args, **kwds), cause=x)

469

470_wargs = _wargs() # PYCHOK singleton

471

472

473 def _Intersecant2(gl, lat0, lon0, radius, tol=_TOL, form=F_D): # MCCABE in LatLonEllipsoidalBaseDI.intersecant2, .geodesicx.gxline.Intersecant2

474 # (INTERNAL) Return a 2-Tuple C{(P, Q)} with the intersections of

475 # a circle at C{lat0, lon0} and a geodesic line, each a C{GDict}.

476 r = Radius_(radius)

477 n = _dunder_nameof(_Intersecant2)[1:]

478 _P = gl.Position

479 _I = gl.geodesic.Inverse

480 _a = fabs

481

482 def _R3(s):

483 # radius, intersection, etc. at distance C{s}

484 P = _P(s)

485 d = _I(lat0, lon0, P.lat2, P.lon2)

486 return _a(d.s12), P, d

487

488 def _bisect2(s, c, Rc, r, tol):

489 b = c

490 while True:

491 b += s

492 Rb, P, d = _R3(b)

493 if Rb > r:

494 break

495 # assert Rb > r > Rc

496 for i in range(_TRIPS): # 47-48

497 s = (b + c) * _0_5

498 R, P, d = _R3(s)

499 if Rb > R > r:

500 b, Rb = s, R

501 elif Rc < R < r:

502 c, Rc = s, R

503 t = _a(b - c)

504 if t < tol: # or _a(R - r) < tol:

505 break

506 else:

507 # t = min(t, _a(R - r))

508 raise ValueError(Fmt.no_convergence(t, tol))

509 i += C.iteration # combine iterations

510 P.set_(lat0=lat0, lon0=lon0, azi0=d.azi1, iteration=i,

511 a02=d.a12, s02=d.s12, at=d.azi2 - P.azi2, name=n)

512 return P, s

513

514 # get the perpendicular intersection of 2

515 # geodesics, one as a pseudo-rhumb line

516 C = _PlumbTo(gl, lat0, lon0, tol=tol)

517 try:

518 a = _a(C.s02) # distance between centers

519 if a < r:

520 c = C.s12 # distance along pseudo-rhumb line

521 h = _copysign(r, c) # past half chord length

522 P, p = _bisect2( h, c, a, r, tol)

523 Q, q = _bisect2(-h, c, a, r, tol)

524 if _a(p - q) < max(EPS, tol):

525 Q = P

526 elif a > r:

527 raise ValueError(_too_(Fmt.distant(a)))

528 else: # tangential

529 P = Q = C

530 except Exception as x:

531 t = _LLB(C.lat2, C.lon2).toStr(form=form)

532 t = _SPACE_(x, _plumb_, _to_, Fmt.PAREN(t))

533 raise IntersectionError(t, txt=None, cause=x)

534

535 return P, Q

536

537

538 def _PlumbTo(gl, lat0, lon0, est=None, tol=_TOL):

539 # (INTERNAL) Return the I{perpendicular} intersection of

540 # a geodesic from C{(lat0, lon0)} and a geodesic (line).

541 pl = _MODS.rhumb.bases._PseudoRhumbLine(gl)

542 return pl.PlumbTo(lat0, lon0, exact=gl.geodesic,

543 est=est, tol=tol)

544

545# **) MIT License

546#

547# Copyright (C) 2016-2024 -- mrJean1 at Gmail -- All Rights Reserved.

548#

549# Permission is hereby granted, free of charge, to any person obtaining a

550# copy of this software and associated documentation files (the "Software"),

551# to deal in the Software without restriction, including without limitation

552# the rights to use, copy, modify, merge, publish, distribute, sublicense,

553# and/or sell copies of the Software, and to permit persons to whom the

554# Software is furnished to do so, subject to the following conditions:

555#

556# The above copyright notice and this permission notice shall be included

557# in all copies or substantial portions of the Software.

558#

559# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

560# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

561# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

562# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR

563# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,

564# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

565# OTHER DEALINGS IN THE SOFTWARE.