Coverage for pygeodesy/geodesicx/gxbases.py: 93%

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1 

2# -*- coding: utf-8 -*- 

3 

4u'''(INTERNAL) Private L{geodesicx} base class, functions and constants. 

5 

6Copyright (C) U{Charles Karney<mailto:Karney@Alum.MIT.edu>} (2008-2023) 

7and licensed under the MIT/X11 License. For more information, see the 

8U{GeographicLib<https://GeographicLib.SourceForge.io>} documentation. 

9''' 

10 

11from pygeodesy.basics import isodd, _MODS 

12from pygeodesy.constants import _0_0, _100_0 

13from pygeodesy.errors import _or, _xkwds_item2, _not_ 

14from pygeodesy.fmath import hypot as _hypot 

15# from pygeodesy.interns import _not_ # from .errors 

16from pygeodesy.karney import _CapsBase, GeodesicError, _2cos2x, _sum2_ 

17# from pygeodesy.lazily import _MODS, printf # .basics, _MODS 

18 

19from math import ldexp as _ldexp 

20 

21__all__ = () 

22__version__ = '24.03.15' 

23 

24# valid C{nC4}s and C{C4order}s, see _xnC4 below 

25_nC4s = {24: 2900, 27: 4032, 30: 5425} 

26 

27 

28class _GeodesicBase(_CapsBase): # in .geodsolve 

29 '''(INTERNAL) Base class for C{[_]Geodesic*Exact}. 

30 ''' 

31# def toRepr(self, prec=6, sep=_COMMASPACE_, **unused): # PYCHOK signature 

32# '''Return this C{GeodesicExact*} items string. 

33# 

34# @kwarg prec: The C{float} precision, number of decimal digits (0..9). 

35# Trailing zero decimals are stripped for B{C{prec}} values 

36# of 1 and above, but kept for negative B{C{prec}} values. 

37# @kwarg sep: Separator to join (C{str}). 

38# 

39# @return: C{GeodesicExact*} (C{str}). 

40# ''' 

41# return Fmt.PAREN(self.named, self.toStr(prec=prec, sep=sep)) 

42 pass 

43 

44 

45class _Gfloats(dict): 

46 '''(INTERNAL) Uniquify floats. 

47 ''' 

48 n = 0 # total number of floats 

49 nC4 = 0 

50 

51 def __init__(self, nC4): # PYCHOK signature 

52 self.nC4 = nC4 

53 

54 def __call__(self, fs): 

55 '''Return a tuple of "uniquified" floats. 

56 ''' 

57 self.n += len(fs) 

58 _f = self.setdefault 

59 return tuple(_f(f, f) for f in map(float, fs)) # PYCHOK as attr 

60 

61 def prints(self): 

62 n, u = self.n, len(self.keys()) 

63 d = (n - u) * _100_0 / n 

64 _MODS.lazily.printf('_CX_%d: n=%d, u=%d, d=%.1f%%', self.nC4, n, u, d) # XXX 

65 

66 

67def _cosSeries(c4s, sx, cx): # PYCHOK shared .geodesicx.gx and -.gxline 

68 '''(INTERNAL) I{Karney}'s cosine series expansion using U{Clenshaw 

69 summation<https://WikiPedia.org/wiki/Clenshaw_algorithm>}. 

70 ''' 

71 ar = _2cos2x(cx, sx) 

72 y0 = t0 = y1 = t1 = _0_0 

73 c4 = list(c4s) 

74 _c4 = c4.pop 

75 _s2 = _sum2_ 

76 if isodd(len(c4)): 

77 y0 = _c4() 

78 while c4: 

79 # y1 = ar * y0 - y1 + c4.pop() 

80 # y0 = ar * y1 - y0 + c4.pop() 

81 y1, t1 = _s2(ar * y0, ar * t0, -y1, -t1, _c4()) 

82 y0, t0 = _s2(ar * y1, ar * t1, -y0, -t0, _c4()) 

83 # s = cx * (y0 - y1) 

84 s, _ = _s2(cx * y0, _0_0, cx * t0, -cx * y1, -cx * t1) 

85 return s 

86 

87 

88_f = float # in _f2 and .geodesicx._C4_24, _27 and _30 

89 

90 

91def _f2(hi, lo): # in .geodesicx._C4_24, _27 and _30 

92 '''(INTERNAL) For C{_coeffs}. 

93 ''' 

94 return _ldexp(_f(hi), 52) + _f(lo) 

95 

96 

97def _sincos12(sin1, cos1, sin2, cos2, sineg0=False): # PYCHOK shared 

98 '''(INTERNAL) Compute the sine and cosine of angle 

99 M{ang12 = atan2(sin2, cos2) - atan2(sin1, cos1)}. 

100 

101 Negate C{sin1} to get C{sin12} and C{cos12} of the sum 

102 M{ang12 = atan2(sin2, cos2) + atan2(sin1, cos1)}. 

103 

104 @kwarg sineg0: If C{True}, make negative C{sin12} zero (C{bool}). 

105 

106 @return: 2-Tuple C{(sin12, cos12)}. 

107 ''' 

108 s = sin2 * cos1 - sin1 * cos2 

109 c = cos2 * cos1 + sin1 * sin2 

110 if sineg0 and s < 0: 

111 s = _0_0 # max(s, _0_0) or NEG0? 

112 return s, c 

113 

114 

115def _sin1cos2(sin1, cos1, sin2, cos2): # PYCHOK shared 

116 '''(INTERNAL) Compute the C{sin1 * cos2} sine and its cosine. 

117 

118 @return: 2-Tuple C{(sin1 * cos2, hypot(sin1 * sin2, cos1)}. 

119 ''' 

120 s = sin1 * cos2 

121 c = _hypot(sin1 * sin2, cos1) 

122 return s, c # _norm2(s, c) 

123 

124 

125def _xnC4(**name_nC4): 

126 '''(INTERNAL) Validate C{C4order}. 

127 ''' 

128 n, nC4 = _xkwds_item2(name_nC4) 

129 if nC4 not in _nC4s or not isinstance(nC4, int): 

130 raise GeodesicError(n, nC4, txt=_not_(_or(*map(str, _nC4s)))) 

131 return _nC4s[nC4] 

132 

133 

134# **) MIT License 

135# 

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

137# 

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

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

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

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

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

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

144# 

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

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

147# 

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

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

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

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

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

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

154# OTHER DEALINGS IN THE SOFTWARE.