1

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

3

4 u'''World Geographic Reference System (WGRS) en-/decoding, aka GEOREF.

5

6 Class L{Georef} and several functions to encode, decode and inspect WGRS

7(or GEOREF) references.

8

9 Transcoded from I{Charles Karney}'s C++ class U{Georef

10<https://GeographicLib.SourceForge.io/C++/doc/classGeographicLib_1_1Georef.html>},

11 but with modified C{precision} and extended with C{height} and C{radius}.

12

13@see: U{World Geographic Reference System

14 <https://WikiPedia.org/wiki/World_Geographic_Reference_System>}.

15'''

16 from pygeodesy.basics import isstr, typename

17 from pygeodesy.constants import INT0, _float, _off90, _0_001, \

18 _0_5, _1_0, _2_0, _60_0, _1000_0

19 from pygeodesy.dms import parse3llh

20 from pygeodesy.errors import _ValueError, _xattr, _xStrError

21# from pygeodesy.internals import typename # from .basics

22 from pygeodesy.interns import NN, _0to9_, _AtoZnoIO_, _COMMA_, \

23 _height_, _INV_, _radius_, _SPACE_

24 from pygeodesy.lazily import _ALL_DOCS, _ALL_LAZY

25 from pygeodesy.named import _name2__, nameof, Property_RO

26 from pygeodesy.namedTuples import LatLon2Tuple, LatLonPrec3Tuple

27# from pygeodesy.props import Property_RO # from .named

28 from pygeodesy.streprs import Fmt, _0wd

29 from pygeodesy.units import Height, Int, Lat, Lon, Precision_, \

30 Radius, Scalar_, Str

31 from pygeodesy.utily import ft2m, m2ft, m2NM

32

33 from math import floor

34

35__all__ = _ALL_LAZY.wgrs

36__version__ = '25.04.14'

37

38_Base = 10

39_BaseLen = 4

40_DegChar = _AtoZnoIO_.tillQ

41_Digits = _0to9_

42_LatOrig = -90

43_LatTile = _AtoZnoIO_.tillM

44_LonOrig = -180

45_LonTile = _AtoZnoIO_

46_60B = 60000000000 # == 60_000_000_000 == 60e9

47_MaxPrec = 11

48_Tile = 15 # tile size in degrees

49

50_MaxLen = _BaseLen + 2 * _MaxPrec

51_MinLen = _BaseLen - 2

52

53_LatOrig_60B = _LatOrig * _60B

54_LonOrig_60B = _LonOrig * _60B

55

56_float_Tile = _float(_Tile)

57_LatOrig_Tile = _float(_LatOrig) / _Tile

58_LonOrig_Tile = _float(_LonOrig) / _Tile

59

60

61 def _divmod3(x, _Orig_60B):

62 '''(INTERNAL) Convert B{C{x}} to 3_tuple C{(tile, modulo, fraction)}/

63 '''

64 i = int(floor(x * _60B))

65 i, x = divmod(i - _Orig_60B, _60B)

66 xt, xd = divmod(i, _Tile)

67 return xt, xd, x

68

69

70 def _2fll(lat, lon):

71 '''(INTERNAL) Convert lat, lon.

72 '''

73 # lat, lon = parseDMS2(lat, lon)

74 return (Lat(lat, Error=WGRSError),

75 Lon(lon, Error=WGRSError))

76

77

78 def _2geostr2(georef):

79 '''(INTERNAL) Check a georef string.

80 '''

81 try:

82 n, g = len(georef), georef.upper()

83 p, o = divmod(n, 2)

84 if o or n < _MinLen or n > _MaxLen \

85 or g.startswith(_INV_) or not g.isalnum():

86 raise ValueError()

87 return g, _2Precision(p - 1)

88

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

90 raise WGRSError(typename(Georef), georef, cause=x)

91

92

93 def _2Precision(precision):

94 '''(INTERNAL) Return a L{Precision_} instance.

95 '''

96 return Precision_(precision, Error=WGRSError, low=0, high=_MaxPrec)

97

98

99 class WGRSError(_ValueError):

100 '''World Geographic Reference System (WGRS) encode, decode or other L{Georef} issue.

101 '''

102 pass

103

104

105 class Georef(Str):

106 '''Georef class, a named C{str}.

107 '''

108 # no str.__init__ in Python 3

109 def __new__(cls, lat_gll, lon=None, height=None, precision=3, name=NN):

110 '''New L{Georef} from an other L{Georef} instance or georef

111 C{str} or from a C{LatLon} instance or lat-/longitude C{str}.

112

113 @arg lat_gll: Latitude (C{degrees90}), a georef (L{Georef},

114 C{str}) or a location (C{LatLon}, C{LatLon*Tuple}).

115 @kwarg lon: Logitude (C{degrees180)}, required if B{C{lat_gll}}

116 is C{degrees90}, ignored otherwise.

117 @kwarg height: Optional height in C{meter}, used if B{C{lat_gll}}

118 is a location.

119 @kwarg precision: The desired georef resolution and length (C{int}

120 0..11), see L{encode<pygeodesy.wgrs.encode>}.

121 @kwarg name: Optional name (C{str}).

122

123 @return: New L{Georef}.

124

125 @raise RangeError: Invalid B{C{lat_gll}} or B{C{lon}}.

126

127 @raise TypeError: Invalid B{C{lat_gll}} or B{C{lon}}.

128

129 @raise WGRSError: INValid B{C{lat_gll}}.

130 '''

131 if lon is None:

132 if isinstance(lat_gll, Georef):

133 g, ll, p = str(lat_gll), lat_gll.latlon, lat_gll.precision

134 elif isstr(lat_gll):

135 if _COMMA_ in lat_gll or _SPACE_ in lat_gll:

136 lat, lon, h = parse3llh(lat_gll, height=height)

137 g, ll, p = _encode3(lat, lon, precision, h=h)

138 else:

139 g, ll = lat_gll.upper(), None

140 try:

141 _, p = _2geostr2(g) # validate

142 except WGRSError: # R00H00?

143 p = None # = decode5(g).precision?

144 else: # assume LatLon

145 try:

146 g, ll, p = _encode3(lat_gll.lat, lat_gll.lon, precision,

147 h=_xattr(lat_gll, height=height))

148 except AttributeError:

149 raise _xStrError(Georef, gll=lat_gll) # Error=WGRSError

150 else:

151 g, ll, p = _encode3(lat_gll, lon, precision, h=height)

152

153 self = Str.__new__(cls, g, name=name or nameof(lat_gll))

154 self._latlon = ll

155 self._precision = p

156 return self

157

158 @Property_RO

159 def decoded3(self):

160 '''Get this georef's attributes (L{LatLonPrec3Tuple}).

161 '''

162 lat, lon = self.latlon

163 return LatLonPrec3Tuple(lat, lon, self.precision, name=self.name)

164

165 @Property_RO

166 def decoded5(self):

167 '''Get this georef's attributes (L{LatLonPrec5Tuple}) with

168 height and radius set to C{None} if missing.

169 '''

170 return self.decoded3.to5Tuple(self.height, self.radius)

171

172 @Property_RO

173 def _decoded5(self):

174 '''(INTERNAL) Initial L{LatLonPrec5Tuple}.

175 '''

176 return decode5(self)

177

178 @Property_RO

179 def height(self):

180 '''Get this georef's height in C{meter} or C{None} if missing.

181 '''

182 return self._decoded5.height

183

184 @Property_RO

185 def latlon(self):

186 '''Get this georef's (center) lat- and longitude (L{LatLon2Tuple}).

187 '''

188 lat, lon = self._latlon or self._decoded5[:2]

189 return LatLon2Tuple(lat, lon, name=self.name)

190

191 @Property_RO

192 def latlonheight(self):

193 '''Get this georef's (center) lat-, longitude and height (L{LatLon3Tuple}),

194 with height set to C{INT0} if missing.

195 '''

196 return self.latlon.to3Tuple(self.height or INT0)

197

198 @Property_RO

199 def precision(self):

200 '''Get this georef's precision (C{int}).

201 '''

202 p = self._precision

203 return self._decoded5.precision if p is None else p

204

205 @Property_RO

206 def radius(self):

207 '''Get this georef's radius in C{meter} or C{None} if missing.

208 '''

209 return self._decoded5.radius

210

211 def toLatLon(self, LatLon=None, height=None, **name_LatLon_kwds):

212 '''Return (the center of) this georef cell as a C{LatLon}.

213

214 @kwarg LatLon: Class to use (C{LatLon}) or C{None}.

215 @kwarg height: Optional height (C{meter}), overriding this height.

216 @kwarg name_LatLon_kwds: Optional C{B{name}=NN} (C{str}) and optionally,

217 additional B{C{LatLon}} keyword arguments, ignored if C{B{LatLon}

218 is None}.

219

220 @return: This georef location (B{C{LatLon}}) or if C{B{LatLon} is None},

221 a L{LatLon3Tuple}C{(lat, lon, height)}.

222

223 @raise TypeError: Invalid B{C{LatLon}} or B{C{name_LatLon_kwds}}.

224 '''

225 n, kwds = _name2__(name_LatLon_kwds, _or_nameof=self)

226 h = (self.height or INT0) if height is None else height # _heigHt

227 r = self.latlon.to3Tuple(h) if LatLon is None else LatLon(

228 *self.latlon, height=h, **kwds)

229 return r.renamed(n) if n else r

230

231

232 def decode3(georef, center=True):

233 '''Decode a C{georef} to lat-, longitude and precision.

234

235 @arg georef: To be decoded (L{Georef} or C{str}).

236 @kwarg center: If C{True}, use the georef's center, otherwise

237 the south-west, lower-left corner (C{bool}).

238

239 @return: A L{LatLonPrec3Tuple}C{(lat, lon, precision)}.

240

241 @raise WGRSError: Invalid B{C{georef}}, INValid, non-alphanumeric

242 or odd length B{C{georef}}.

243 '''

244 def _digit(ll, g, i, m):

245 d = _Digits.find(g[i])

246 if d < 0 or d >= m:

247 raise _Error(i)

248 return ll * m + d

249

250 def _Error(i):

251 return WGRSError(Fmt.SQUARE(georef=i), georef)

252

253 def _index(chars, g, i):

254 k = chars.find(g[i])

255 if k < 0:

256 raise _Error(i)

257 return k

258

259 g, precision = _2geostr2(georef)

260 lon = _index(_LonTile, g, 0) + _LonOrig_Tile

261 lat = _index(_LatTile, g, 1) + _LatOrig_Tile

262

263 u = _1_0

264 if precision > 0:

265 lon = lon * _Tile + _index(_DegChar, g, 2)

266 lat = lat * _Tile + _index(_DegChar, g, 3)

267 m, p = 6, precision - 1

268 for i in range(_BaseLen, _BaseLen + p):

269 lon = _digit(lon, g, i, m)

270 lat = _digit(lat, g, i + p, m)

271 u *= m

272 m = _Base

273 u *= _Tile

274

275 if center:

276 lon = lon * _2_0 + _1_0

277 lat = lat * _2_0 + _1_0

278 u *= _2_0

279 u = _Tile / u

280 return LatLonPrec3Tuple(Lat(lat * u, Error=WGRSError),

281 Lon(lon * u, Error=WGRSError),

282 precision, name=nameof(georef))

283

284

285 def decode5(georef, center=True):

286 '''Decode a C{georef} to lat-, longitude, precision, height and radius.

287

288 @arg georef: To be decoded (L{Georef} or C{str}).

289 @kwarg center: If C{True}, use the georef's center, otherwise the

290 south-west, lower-left corner (C{bool}).

291

292 @return: A L{LatLonPrec5Tuple}C{(lat, lon, precision, height, radius)}

293 where C{height} and/or C{radius} are C{None} if missing.

294

295 @raise WGRSError: Invalid B{C{georef}}.

296 '''

297 def _h2m(kft, g_n):

298 return Height(ft2m(kft * _1000_0), name=g_n, Error=WGRSError)

299

300 def _r2m(NM, g_n):

301 return Radius(NM / m2NM(1), name=g_n, Error=WGRSError)

302

303 def _split2(g, Unit, _2m):

304 n = typename(Unit)

305 i = max(g.find(n[0]), g.rfind(n[0]))

306 if i > _BaseLen:

307 return g[:i], _2m(int(g[i+1:]), _SPACE_(georef, n))

308 else:

309 return g, None

310

311 g = Str(georef, Error=WGRSError)

312

313 g, h = _split2(g, Height, _h2m) # H is last

314 g, r = _split2(g, Radius, _r2m) # R before H

315

316 return decode3(g, center=center).to5Tuple(h, r)

317

318

319 def encode(lat, lon, precision=3, height=None, radius=None): # MCCABE 14

320 '''Encode a lat-/longitude as a C{georef} of the given precision.

321

322 @arg lat: Latitude (C{degrees}).

323 @arg lon: Longitude (C{degrees}).

324 @kwarg precision: Optional, the desired C{georef} resolution and length

325 (C{int} 0..11).

326 @kwarg height: Optional, height in C{meter}, see U{Designation of area

327 <https://WikiPedia.org/wiki/World_Geographic_Reference_System>}.

328 @kwarg radius: Optional, radius in C{meter}, see U{Designation of area

329 <https://WikiPedia.org/wiki/World_Geographic_Reference_System>}.

330

331 @return: The C{georef} (C{str}).

332

333 @raise RangeError: Invalid B{C{lat}} or B{C{lon}}.

334

335 @raise WGRSError: Invalid B{C{precision}}, B{C{height}} or B{C{radius}}.

336

337 @note: The B{C{precision}} value differs from I{Karney}'s U{Georef<https://

338 GeographicLib.SourceForge.io/C++/doc/classGeographicLib_1_1Georef.html>}.

339 The C{georef} length is M{2 * (precision + 1)} and the C{georef}

340 resolution is I{15°} for B{C{precision}} 0:, I{1°} for 1, I{1′} for 2,

341 I{0.1′} for 3, I{0.01′} for 4, ... up to I{10**(2 - precision)′}.

342 '''

343 def _option(name, m, m2_, K):

344 f = Scalar_(m, name=name, Error=WGRSError)

345 return NN(name[0].upper(), int(m2_(f * K) + _0_5))

346

347 g, _, _ = _encode3(lat, lon, precision)

348 if radius is not None: # R before H

349 g += _option(_radius_, radius, m2NM, _1_0)

350 if height is not None: # H is last

351 g += _option(_height_, height, m2ft, _0_001)

352 return g

353

354

355 def _encode3(lat, lon, precision, h=None):

356 '''Return 3-tuple C{(georef, (lat, lon), p)}.

357 '''

358 p = _2Precision(precision)

359

360 lat, lon = _2fll(lat, lon)

361

362 if h is None:

363 xt, xd, x = _divmod3( lon, _LonOrig_60B)

364 yt, yd, y = _divmod3(_off90(lat), _LatOrig_60B)

365

366 g = _LonTile[xt], _LatTile[yt]

367 if p > 0:

368 g += _DegChar[xd], _DegChar[yd]

369 p -= 1

370 if p > 0:

371 d = pow(_Base, _MaxPrec - p)

372 x = _0wd(p, x // d)

373 y = _0wd(p, y // d)

374 g += x, y

375 g = NN.join(g)

376 else:

377 g = encode(lat, lon, precision=p, height=h)

378

379 return g, (lat, lon), p # XXX Georef(''.join(g))

380

381

382 def precision(res):

383 '''Determine the L{Georef} precision to meet a required (geographic)

384 resolution.

385

386 @arg res: The required resolution (C{degrees}).

387

388 @return: The L{Georef} precision (C{int} 0..11).

389

390 @raise ValueError: Invalid B{C{res}}.

391

392 @see: Function L{wgrs.encode} for more C{precision} details.

393 '''

394 r = Scalar_(res=res)

395 for p in range(_MaxPrec):

396 if resolution(p) <= r:

397 return p

398 return _MaxPrec

399

400

401 def resolution(prec):

402 '''Determine the (geographic) resolution of a given L{Georef} precision.

403

404 @arg prec: The given precision (C{int}).

405

406 @return: The (geographic) resolution (C{degrees}).

407

408 @raise ValueError: Invalid B{C{prec}}.

409

410 @see: Function L{wgrs.encode} for more C{precision} details.

411 '''

412 p = Int(prec=prec, Error=WGRSError)

413 if p > 1:

414 p = min(p, _MaxPrec) - 1

415 r = _1_0 / (pow(_Base, p) * _60_0)

416 elif p < 1:

417 r = _float_Tile

418 else:

419 r = _1_0

420 return r

421

422

423__all__ += _ALL_DOCS(decode3, decode5, # functions

424 encode, precision, resolution)

425

426# **) MIT License

427#

428# Copyright (C) 2016-2025 -- mrJean1 at Gmail -- All Rights Reserved.

429#

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

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

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

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

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

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

436#

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

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

439#

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

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

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

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

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

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

446# OTHER DEALINGS IN THE SOFTWARE.