Coverage for pyrdnap / rdnap2018.py: 93%
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« prev ^ index » next coverage.py v7.14.0, created at 2026-06-10 10:52 -0400
2# -*- coding: utf-8 -*-
4u'''Main classes L{RDNAP2018v1} and L{RDNAP2018v2} follow C{variant 1} respectively C{variant 2} of
5the U{RDNAPTRANS(tm)2018_v220627<https://formulieren.kadaster.nl/aanvragen_rdnaptrans>} specification.
6Each provide a C{forward} method to convert geodetic lat-/longitudes and heights to C{RD} coodinates
7and C{NAP} heights and a C{reverse} method for converting the other way.
9The L{RDNAP2018v1.forward} and C{.reverse} results are within the C{RDNAPTRANS(tm)2018_v220627}
10self-validation requirements of C{0.000000010 degrees} respectively C{0.0010 meter} for points inside
11the C{RD} region, see B{C{Note below}}.
13@note: L{RDNAP2018v1}, L{RDNAP2018v2}, C{PyRDNAP} and C{pyrdnap} have B{not been formally validated}
14 and are B{not certified} to carry the trademark C{RDNAPTRANS(tm)}.
15'''
16# make sure int/int division yields float quotient, see .basics
17from __future__ import division as _; del _ # noqa: E702 ;
19from pyrdnap.rd0 import _RD, _RD0 as A0, RDNAP7Tuple
20from pyrdnap.v_grids import RDNAPError, _V_grid, _v_gridz_import
21from pyrdnap.__pygeodesy import (_0_0, _0_5, _1_0, _2_0,
22 _isNAN, _isNAN0, _earth_datum,
23 _ALL_DOCS, _ALL_OTHER, _FOR_DOCS,
24 _NamedBase)
25from pygeodesy import (map1, EPS0, EPS1, NAN, PI_2, PI, PI2, # "consterns"
26 Datum, Ellipsoid, LatLonDatum3Tuple, # datums, ellipsoids
27 Property_RO, property_RO, property_ROnce, # props
28 Lamd, Lat, Lon, Phid, # units
29 sincos2, sincos2d) # utily
31from math import asin, atan, copysign, degrees, exp, \
32 fabs, floor, hypot, radians, sin, sqrt
34__all__ = ()
35__version__ = '26.06.09'
37_TOL_D = 1e-9 # degrees 2.3.3f+
38_TOL_M = 1e-6 # meter
39_TOL_R = radians(_TOL_D) # 2e-11
40_TRIPS = 16 # 5..6 sufficient
43class _RDNAPbase(_NamedBase): # in .rd0._RD.regionB
44 '''(INTERNAL) L{RDNAP2018v1}C{/-v2} base class.
45 '''
46 _datum = None # forward, v1 reverse Datum, lazily (GRS80)
47 _EETRS = None # forward, v1 reverse Ellipsoid, lazily
48 _raiser = False
50 def __init__(self, a_ellipsoid=None, f=None, raiser=False, **name):
51 '''New C{RDNAP2018v1} or C{-v2} instance.
53 @kwarg a_ellipsoid: An ellipsoid (L{Ellipsoid}) or the ellipsoid's equatorial
54 radius (C{scalar}, conventionally in C{meter}), see B{C{f}}
55 or a datum (L{Datum}). Default C{Datums.GRS80} for ETRS89.
56 @kwarg f: The flattening of the ellipsoid (C{scalar}) if B{C{a_ellipsoid}} is
57 specified as C{scalar}, ignored otherwise.
58 @kwarg raiser: If C{True} raise an L{RDNAPError} for lat-/longitudes outside
59 the C{RD} region (C{bool}).
60 @kwarg name: Optional name (C{str}).
62 @raise RDNAPError: Ellipsoid (or datum) is not oblate (i.e. is spherical or
63 prolate) or the datum's C{transform} is not C{unity}.
64 '''
65 if a_ellipsoid is f is None:
66 self._datum = A0.D80 # GRS80 (ETRS89)
67 else:
68 _earth_datum(self, a_ellipsoid, f, **name) # sets self._datum
69 self._EETRS = E = self._datum.ellipsoid
70 if not E.isOblate:
71 raise RDNAPError('not oblate: %r' % (E,))
72 if raiser: # PYCHOK no cover
73 T = self._datum.transform
74 if not T.isunity:
75 raise RDNAPError('not unity: %r' % (T,))
76 self._raiser = True
77 if name:
78 self.name = name
80 def forward(self, lat, lon, height=0, raiser=None, name='forward'):
81 '''Convert GRS80 (ETRS98) geodetic C{(B{lat}, B{lon})} and B{C{height}}
82 to local C{(RDx, RDy)} coordinates and C{NAPh} quasi-geoid-height.
84 @arg lat: Latitude (C{degrees} geodetic).
85 @arg lon: Longitude (C{degrees} geodetic).
86 @kwarg height: Height, optional (C{meter} above geoid) or C{NAN}
87 to ignore C{NAPh} interpolation.
88 @kwarg raiser: If C{True} raise an L{RDNAPError} if B{C{lat}} or
89 B{C{lon}} is outside the C{RD} region (C{bool}),
90 if C{False} don't, overriding property C{raiser}.
91 @kwarg name: Optional name (C{str}).
93 @return: An L{RDNAP7Tuple}C{(RDx, RDy, NAPh, lat, lon, height, datum)}
94 with local C{RDx}, C{RDy} coordinates and C{NAPh} height.
95 '''
96 lat, lon = Lat(lat), Lon(lon)
97 lat0, lon0 = \
98 lat_, lon_ = self._forwardXform2(raiser, lat, lon)
99 for _ in range(_TRIPS): # 2.3.3a-f, 1..2
100 latc, lonc = self._rdlatlon2(lat_, lon_, lat0, lon0)
101 if fabs(latc - lat_) < _TOL_D and \
102 fabs(lonc - lon_) < _TOL_D:
103 break
104 lat_, lon_ = latc, lonc
106 phiClamC = _ellipsoidal2spherical(latc, lonc)
107 RDx, RDy = _spherical2oblique(*phiClamC)
108 NAPh = NAN if _isNAN(height) else (height - # NOT lat0, lon0
109 self._rdNAPh_v(lat, lon, latc, lonc)) # 2.5.2
110 return RDNAP7Tuple(RDx, RDy, NAPh,
111 lat, lon, height, self.forwardDatum, name=name)
113 def forward3(self, lat, lon, name='forward3'):
114 '''Datum transform C{(B{lat}, B{lon})} from GRS80 (ETRS98) to Bessel1841 (RD-Bessel).
116 @return: A L{LatLonDatum3Tuple}C{(lat, lon, datum)}.
117 '''
118 x, y, z = _geodetic2cartesian(lat, lon, A0.H0_ETRS, self._EETRS)
119 x, y, z = _RD._xETRS2RD.transform(x, y, z) # pseudo
120 lat, lon = _cartesian2geodetic(x, y, z, A0.E0) # pseudo
121 return LatLonDatum3Tuple(lat, lon, A0.D0, name=name)
123 @property_RO
124 def forwardDatum(self):
125 '''Get the C{forward} datum (L{Datum}, default GRS80).
126 '''
127 return self._datum
129 def _forwardXform2(self, *args): # PYCHOK no cover
130 return self._notOverloaded(*args)
132 def _inside2(self, raiser, lat, lon, **as89):
133 # if RD-Bessel C{(lat, lon)} is not inside C{RD} region
134 # raise an error if C{raiser} or self.raiser is True
135 if (raiser or (raiser is None and self._raiser)) and \
136 not _RD.isinside(lat, lon, **as89):
137 raise self._outsidError(lat, lon)
138 return lat, lon
140 def isinside(self, lat, lon, as89=False, eps=0):
141 '''Is geodetic C{(B{lat}, B{lon})} inside the C{RD} region[89] (C{bool})?
143 @kwarg as89: Use C{B{as89}=True} for C{RD} region89 and in case
144 C{(B{lat}, B{lon})} are ETRS89 (GRS80), not Bessel1841.
145 @kwarg eps: Over-/undersize the C{RD} region (C{degrees}).
146 '''
147 return _RD.isinside(Lat(lat), Lon(lon), as89, eps)
149 def _outsidError(self, *lat_lon):
150 # format an RDNAPError for C{lat_lon} outside C{RD} region
151 return RDNAPError('%r outside %s' % (lat_lon, self.region))
153 @property_RO
154 def _rdgrid(self): # PYCHOK no cover
155 return self._notOverloaded()
157 def _rdlatlon2(self, lat, lon, lat0=None, lon0=None): # 2.3.2
158 # return the RD-corrected C{(lat, lon)}
159 if _RD.isinside(lat, lon):
160 c_f_N_f6 = _RD._c_f_N_f6(lat, lon)
161 lat_corr = _bilinear(self._rdgrid._lat_corr, *c_f_N_f6)
162 lon_corr = _bilinear(self._rdgrid._lon_corr, *c_f_N_f6)
164 if lat0 is lon0 is None: # reverse
165 lat += lat_corr
166 lon += lon_corr
167 else: # forward
168 lat = lat0 - lat_corr
169 lon = lon0 - lon_corr
170 return lat, lon # NAN, NAN?
172 def rdNAPh(self, lat, lon, raiser=False): # 2.5.1 and 3.5
173 '''Interpolate the C{NAPh} quasi-geoid-height I{within} the C{RD} region.
175 @arg lat: Latitude (C{degrees} geodetic).
176 @arg lon: Longitude (C{degrees} geodetic).
177 @kwarg raiser: If C{True} raise an L{RDNAPError} if B{C{lat}} or
178 B{C{lon}} is outside the C{RD} region (C{bool}),
179 otherwise don't and return C{NAN}.
181 @return: C{NAPh} (C{meter}) or C{NAN} if C{B{raiser} is False} and
182 B{C{lat}} or B{C{lon}} is outside the C{RD} region.
183 '''
184 return self._rdNAPh(Lat(lat), Lon(lon), raiser)
186 def _rdNAPh(self, lat, lon, raiser):
187 # return C{NAPh} at C{(lat, lon)} or C{NAN} if outside
188 if _RD.isinside(lat, lon): # eps=0
189 c_f_N_f6 = _RD._c_f_N_f6(lat, lon)
190 return _bilinear(self._rdgrid._NAP_h, *c_f_N_f6)
191 elif raiser:
192 raise self._outsidError(lat, lon)
193 return NAN # c0 2.5.1e+
195 def _rdNAPh_v(self, lat1, lon1, lat2, lon2):
196 # get C{NAPh} at geodetic C{lat1, lon1} for variant 1 or at the
197 # RD-corrected or inverse-projected C{lat2, lon2} for variant 2
198 if self.variant == 2:
199 lat1, lon1 = lat2, lon2
200 return self._rdNAPh(lat1, lon1, False)
202 @property_ROnce
203 def region(self):
204 '''Get the C{RD} region as L{Bounds4Tuple}C{(latS, lonW, latN, lonE)}, all C{RD-Bessel degrees}.
205 '''
206 return _RD.region
208 @Property_RO
209 def region89(self): # in .rd0._RD.region89
210 '''Get the C{RD} region as L{Bounds4Tuple}C{(latS, lonW, latN, lonE)}, all C{ETRS89 (GRS80) degrees}.
211 '''
212 S, W, N, E = r = self.region # Bounds4Tuple
213 _R = _RDNAPbase
214 _r = _R().reverse3
215 nB = r.name.replace(_R.region.name, _R.region89.name)
216 s, w, _ = _r(S, W)
217 n, e, _ = _r(N, E)
218 return r.classof(s, w, n, e, name=nB) # r.dup(latS=S, ...)
220 def _reverse(self, RDx, RDy, NAPh, asRD, raiser=None, name='reverse', toRD=None):
221 '''(INTERNAL) Convert local C{(B{RDx}, B{RDy})} coordinates and
222 B{C{NAPh}} quasi-geoid-height to GRS80 (ETRS89) or Bessel1841
223 (RD-Bessel) geodetic C{lat}, C{lon} and C{height}.
224 '''
225 phiClamC = _oblique2spherical(RDx, RDy)
226 latlon = _spherical2ellipsoidal(*phiClamC)
228 latc, lonc = self._rdlatlon2(*latlon)
229 lat, lon, d = self._reverseXform3(raiser, latc, lonc)
230 h = NAN if _isNAN(NAPh) else (NAPh +
231 self._rdNAPh_v(lat, lon, *latlon))
233 if (asRD if toRD is None else toRD): # backward comp'y toRD
234 lat, lon, d = latc, lonc, A0.D0
235 return RDNAP7Tuple(RDx, RDy, NAPh,
236 lat, lon, h, d, name=name)
238 def reverse3(self, lat, lon, name='reverse3'):
239 '''Datum transform C{(B{lat}, B{lon})} from Bessel1841 (RD-Bessel) to GRS80 (ETRS98).
241 @return: A L{LatLon3Tuple}C{(lat, lon, datum)}.
242 '''
243 x, y, z = _geodetic2cartesian(lat, lon, A0.H0, A0.E0)
244 x, y, z = _RD._xRD2ETRS.transform(x, y, z)
245 lat, lon = _cartesian2geodetic(x, y, z, self._EETRS)
246 return LatLonDatum3Tuple(lat, lon, self.forwardDatum, name=name)
248 @property_RO
249 def reverseDatum(self):
250 '''Get the I{default} C{reverse} datum (L{Datum}), GRS80 or Bessel1841.
251 '''
252 return {1: self._datum, # self.forwardDatum
253 2: A0.D0}.get(self.variant)
255 def _reverseXform3(self, *raiser_lat_lon):
256 # datum transform C{(lat, lon)} from RD-Bessel to GRS80 (ETRS89)
257 # and raise an C{RDNAPError} if outside the C{RD} region
258 lat, lon = self._inside2(*raiser_lat_lon)
259 return self.reverse3(lat, lon)
261 def similarity(self, inverse=None): # PYCHOK no cover
262 return self._notOverloaded(inverse=inverse)
264 def toStr(self, prec=9, **unused): # PYCHOK signature
265 '''Return this C{RDNAP20181v1} or C{-v2} instance as a string.
267 @kwarg prec: Precision, number of decimal digits (0..9).
269 @return: This C{RDNAP2018v1} or C{-v2} (C{str}).
270 '''
271 return self.attrs('name', 'variant', 'forwardDatum', prec=prec) # _ellipsoid_, _name__
273 @property_RO
274 def variant(self): # PYCHOK no cover
275 return self._notOverloaded()
278class RDNAP2018v1(_RDNAPbase):
279 '''Transformer implementing C{variant 1} of U{RD NAP 2018 v220627
280 <https://formulieren.kadaster.nl/aanvragen_rdnaptrans>}.
282 @note: L{RDNAP2018v1} has B{not been formally validated} and is
283 B{not certified} to carry the trademark C{RDNAPTRANS(tm)}.
284 '''
285 if _FOR_DOCS:
286 __init__ = _RDNAPbase.__init__
287 forward = _RDNAPbase.forward
288 forward3 = _RDNAPbase.forward3
289 reverse3 = _RDNAPbase.reverse3
291 def _forwardXform2(self, raiser, *lat_lon): # PYCHOK signature
292 # datum transform C{(lat, lon)} from ETRS89 to RD-Bessel
293 # and raise an C{RDNAPError} if outside the C{RD} region
294 lat, lon, _ = self.forward3(*lat_lon)
295 return self._inside2(raiser, lat, lon)
297 @property_ROnce
298 def _rdgrid(self):
299 try:
300 from pyrdnap import v1grid
301 except (AttributeError, ImportError, RDNAPError):
302 v1grid = _v_gridz_import(self.variant)
303 return v1grid
305 def reverse(self, RDx, RDy, NAPh=0, asRD=False, **raiser_name):
306 '''Convert a local C{(B{RDx}, B{RDy})} point and B{C{NAPh}} height to
307 B{GRS80 (ETRS89)} geodetic C{(lat, lon, height)}, by default.
309 @arg RDx: Local C{RD} X (C{meter}, conventionally).
310 @arg RDy: Local C{RD} Y (C{meter}, conventionally).
311 @kwarg NAPh: C{NAP} quasi-geoid-height (C{meter}, conventionally)
312 or C{NAN} to ignore C{NAPh} interpolation.
313 @kwarg asRD: Use C{B{asRD}=True} to return Bessel1841 (RD-Bessel) lat-
314 and longitudes instead of GRS80 (ETRS89) (C{bool}).
315 @kwarg raiser_name: Like the C{forward} method, C{B{raiser}=None}
316 (C{bool}) and optional C{B{name}='reverse'} (C{str}).
318 @return: An L{RDNAP7Tuple}C{(RDx, RDy, NAPh, lat, lon, height, datum)}
319 with geodetic C{lat} and C{lon}, C{height} and C{datum}
320 B{GRS80 (ETRS89)} or C{Bessel1841 (RD-Bessel)}.
321 '''
322 return self._reverse(RDx, RDy, NAPh, asRD, **raiser_name)
324 def similarity(self, inverse=False):
325 '''Get the similarity transform (C{Similarity}).
327 @kwarg inverse: Use C{True} for the C{reverse} or C{False}
328 for the C{forward} transform (C{bool}).
329 '''
330 return _RD._xRD2ETRS if inverse else _RD._xETRS2RD
332 @property_ROnce
333 def variant(self):
334 '''Get this C{RDNAP2018}'s variant (C{int}).
335 '''
336 return 1
339class RDNAP2018v2(_RDNAPbase):
340 '''Transformer implementing C{variant 2} of U{RD NAP 2018 v220627
341 <https://formulieren.kadaster.nl/aanvragen_rdnaptrans>}.
343 @note: Method L{RDNAP2018v2.reverse} returns by default GRS80
344 (ETRS89) geodetic lat- and longitudes and datum.
346 @note: L{RDNAP2018v2} has B{not been formally validated} and is
347 B{not certified} to carry the trademark C{RDNAPTRANS(tm)}.
348 '''
349 if _FOR_DOCS:
350 __init__ = _RDNAPbase.__init__
351 forward = _RDNAPbase.forward
352 forward3 = _RDNAPbase.forward3
353 reverse3 = _RDNAPbase.reverse3
355 def _forwardXform2(self, *raiser_lat_lon):
356 # no datum transform C{(lat, lon)} to RD-Bessel, but
357 # raise an C{RDNAPError} if outside the C{RD} region
358 return self._inside2(*raiser_lat_lon) # as89=True
360 @property_ROnce
361 def _rdgrid(self):
362 try:
363 from pyrdnap import v2grid
364 except (AttributeError, ImportError, RDNAPError):
365 v2grid = _v_gridz_import(self.variant)
366 return v2grid
368 def reverse(self, RDx, RDy, NAPh=0, asRD=True, **raiser_name):
369 '''Convert a local C{(B{RDx}, B{RDy})} point and B{C{NAPh}} height to
370 B{GRS80 (ETRS89)} geodetic C{(lat, lon, height)}, by default.
372 @arg RDx: Local C{RD} X (C{meter}, conventionally).
373 @arg RDy: Local C{RD} Y (C{meter}, conventionally).
374 @kwarg NAPh: C{NAP} quasi-geoid-height (C{meter}, conventionally)
375 or C{NAN} to ignore C{NAPh} interpolation.
376 @kwarg asRD: Use C{B{asRD}=False} to return GRS80 (ETRS89) lat- and
377 longitudes instead of Bessel1841 (RD-Bessel) (C{bool}).
378 @kwarg raiser_name: Like the C{forward} method, C{B{raiser}=None}
379 (C{bool}) and optional C{B{name}='reverse'} (C{str}).
381 @return: An L{RDNAP7Tuple}C{(RDx, RDy, NAPh, lat, lon, height, datum)}
382 with geodetic C{lat} and C{lon}, C{height} and C{datum}
383 B{Bessel1841 (RD-Bessel)} or C{GRS80 (ETRS89)}.
384 '''
385 return self._reverse(RDx, RDy, NAPh, asRD, **raiser_name)
387 def similarity(self, *unused): # PYCHOK signature
388 '''Get the similarity transform, always C{None}.
389 '''
390 return None
392 @property_ROnce
393 def variant(self):
394 '''Get this C{RDNAP2018}'s variant (C{int}).
395 '''
396 return 2
399def _atan3(y, x, x0): # 2.2.3e and 3.1.1i
400 # equiv to math.atan2 iff x0 is y
401 if x > 0:
402 r = atan(y / x)
403 elif x < 0:
404 r = atan(y / x) + copysign(PI, x0)
405 else:
406 r = copysign(PI_2, x0) if x0 else _0_0
407 return r
410def _atan_exp(w): # 2.4.1c
411 return atan(exp(w)) * _2_0 - PI_2
414def _bilinear(v_grid, c_latI, f_latI, latN_f, # 2.3.1f and g
415 c_lonI, f_lonI, lonN_f):
416 # interpolate a lat_corr_, lon_corr_ or NAP_h...
417 assert isinstance(v_grid, _V_grid), v_grid
418 ne = v_grid(c_latI, c_lonI)
419 nw = v_grid(c_latI, f_lonI)
420 se = v_grid(f_latI, c_lonI)
421 sw = v_grid(f_latI, f_lonI)
422 lonN_f1 = _1_0 - lonN_f # == 1 - (lonN - f_lonN)
423 return (ne * lonN_f + nw * lonN_f1) * latN_f + \
424 (se * lonN_f + sw * lonN_f1) * (_1_0 - latN_f)
427def _cartesian2geodetic(x, y, z, E): # 2.2.3 == EcefUPC.reverse?
428 # convert cartesian C{(x, y, z)} to C{E}-geodetic C{(lat, lon)}
429 r = hypot(x, y)
430 if r > _TOL_M:
431 a = E.a * E.e2
432 phi_ = atan(z / r) # atan2(z, r)
433 for _ in range(_TRIPS): # 4..6
434 s = sin(phi_)
435 s *= a / sqrt(_1_0 - s**2 * E.e2)
436 phi = atan((z + s) / r) # atan2(z + s, r)
437 if fabs(phi - phi_) < _TOL_R:
438 break
439 phi_ = phi
440 else:
441 phi = copysign(PI_2, z)
442 lam = _atan3(y, x, y)
443 return map1(degrees, phi, lam) # lat, lon
446def _ellipsoidal2spherical(lat, lon): # 2.4.1
447 # convert RD-Bessel C{(lat, lon)} to spherical C{(𝛷, 𝛬)}
448 phiC = phi = Phid(lat)
449 if PI_2 > phi > -PI_2: # 2.4.1c
450 q = A0.log_tan(phi) - A0.log_e_2(phi)
451 w = A0.N0 * q + A0.M0 # 2.4.1b
452 phiC = _atan_exp(w)
453 lamC = (Lamd(lon) - A0.LAM0) * A0.N0 + A0.LAM0C # 2.4.1d
454 return phiC, lamC # -Capital 𝛷, 𝛬
457def _eq0(r, r0=_0_0):
458 return fabs(r - r0) < _TOL_R
461# def _eq0d(d, d0=_0_0):
462# return fabs(d - d0) < _TOL_D
465def _geodetic2cartesian(lat, lon, h, E): # 2.2.1
466 # convert C{E}-geodetic C{(lat, lon)} to cartesian C{(x, y, z)}
467 y, x = sincos2d(lon)
468 z, c = sincos2d(lat)
469 n = E.a / sqrt(_1_0 - z**2 * E.e2)
470 H = _isNAN0(h)
471 c *= n + H
472 x *= c
473 y *= c
474 z *= n * (_1_0 - E.e2) + H
475 return x, y, z
478def _ne0(r, r0=_0_0):
479 return fabs(r - r0) > _TOL_R
482# def _ne0d(d, d0=_0_0):
483# return fabs(d - d0) > _TOL_D
486def _oblique2spherical(x, y): # 3.1.1
487 # inverse oblique stereographic conformal projection from
488 # C{RD (x, y)} to spherical C{(𝛷, 𝛬)}, see C++ function
489 # sterea_e_inverse in U{Proj/src/projections/sterea.cpp
490 # <https://Proj.org/en/stable/operations/projections/sterea.html>}
491 x -= A0.X0
492 y -= A0.Y0
493 r = hypot(x, y)
494 if r > _TOL_M: # x and y
495 s0, c0 = A0.sincos2PHI0C
496 sp, cp = sincos2(atan(r / A0.RK2) * _2_0) # psi atan2(r, A0.RK2)
497 ca = sp * y / r
498 xN = cp * c0 - ca * s0
499 yN = sp * x / r
500 zN = cp * s0 + ca * c0
501 phiC = asin(zN)
502 else:
503 _, xN = A0.sincos2PHI0C
504 yN = _0_0
505 phiC = A0.PHI0C # asin(sin(PHI0C))
506 lamC = _atan3(yN, xN, x) + A0.LAM0C
507 return phiC, lamC # -Capital 𝛷, 𝛬
510def _spherical2ellipsoidal(phiC, lamC): # 3.1.2
511 # inverse Gauss conformal projection from
512 # spherical C{(𝛷, 𝛬)} to RD-Bessel C{(lat, lon)}
513 phi = phiC
514 if PI_2 > phi > -PI_2:
515 q = (A0.log_tan(phi) - A0.M0) / A0.N0
516# w = A0.log_tan(phi)
517 for _ in range(_TRIPS): # 3..6
518 phi_ = phi
519 phi = _atan_exp(A0.log_e_2(phi) + q)
520 if fabs(phi - phi_) < _TOL_R:
521 break
522 lam = (lamC - A0.LAM0C) / A0.N0 + A0.LAM0
523 lam += floor((PI - lam) / PI2) * PI2
524 return map1(degrees, phi, lam) # lat, lon
527def _spherical2oblique(phiC, lamC): # 2.4.2
528 # oblique stereographic conformal projection
529 # from spherical C{(𝛷, 𝛬)} to C{RD (x, y)}
530 x = A0.X0 # 2.4.2g
531 y = A0.Y0 # 2.4.2h
532 a = phiC - A0.PHI0C # 𝛷 - 𝛷0
533 b = lamC - A0.LAM0C # 𝛬 - 𝛬0
534 if (_ne0(a) or _ne0(b)) and (_ne0(phiC, -A0.PHI0C) or
535 _ne0(lamC, -A0.LAM0C + PI)):
536 s0, c0 = A0.sincos2PHI0C # sin(𝛷0), cos(𝛷0)
537 s, c = sincos2(phiC) # sin(𝛷), cos(𝛷)
538 sp_22 = sin(a * _0_5)**2 + \
539 sin(b * _0_5)**2 * c * c0 # sin(𝜓/2)**2
540 if EPS0 < sp_22 < EPS1:
541 # r = 2kR * tan(𝜓/2)
542 # q = r / (sin(𝜓/2) * cos(𝜓/2) * 2)
543 # = 2kR * sin(𝜓/2) / (sin(𝜓/2) * cos(𝜓/2)**2 * 2)
544 # = 2kR / (cos(𝜓/2)**2 * 2)
545 # = 2kR / ((1 - sin(𝜓/2)**2) * 2)
546 # = 2kR / (2 - sin(𝜓/2)**2 * 2)
547 t = sp_22 * _2_0 # 0 < t < 2
548 q = A0.RK2 / (_2_0 - t)
549 x += q * (c * sin(b))
550 y += q * (s - s0 + s0 * t) / c0
551 elif _eq0(a) and _eq0(b):
552 pass
553 else: # if _eq0(phiC, -A0.PHI0C) and _eq0(lamC, A0.LAM0C - PI):
554 x = y = NAN
555# else:
556# raise RDNAPError(str((phiC, lamC)))
557 return x, y
560__all__ += _ALL_DOCS(_RDNAPbase)
561__all__ += _ALL_OTHER(RDNAP2018v1, RDNAP2018v2, RDNAPError,
562 Datum, Ellipsoid, LatLonDatum3Tuple) # passed along from PyGeodesy
564# **) MIT License
565#
566# Copyright (C) 2026-2026 -- mrJean1 at Gmail -- All Rights Reserved.
567#
568# Permission is hereby granted, free of charge, to any person obtaining a
569# copy of this software and associated documentation files (the "Software"),
570# to deal in the Software without restriction, including without limitation
571# the rights to use, copy, modify, merge, publish, distribute, sublicense,
572# and/or sell copies of the Software, and to permit persons to whom the
573# Software is furnished to do so, subject to the following conditions:
574#
575# The above copyright notice and this permission notice shall be included
576# in all copies or substantial portions of the Software.
577#
578# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
579# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
580# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
581# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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583# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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