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 

14from pygeodesy.fmath import hypot as _hypot 

15from pygeodesy.karney import _CapsBase, GeodesicError, _2cos2x, _sum2_ 

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

17 

18from math import ldexp as _ldexp 

19 

20__all__ = () 

21__version__ = '24.05.19' 

22 

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

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

25 

26 

27class _GeodesicBase(_CapsBase): # in .geodsolve 

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

29 ''' 

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

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

32# 

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

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

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

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

37# 

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

39# ''' 

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

41 pass 

42 

43 

44class _Gfloats(dict): 

45 '''(INTERNAL) Uniquify floats. 

46 ''' 

47 n = 0 # total number of floats 

48 nC4 = 0 

49 

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

51 self.nC4 = nC4 

52 

53 def __call__(self, fs): 

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

55 ''' 

56 self.n += len(fs) 

57 _f = self.setdefault 

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

59 

60 def prints(self): 

61 n, u = self.n, len(self.keys()) 

62 d = (n - u) * _100_0 / n 

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

64 

65 

66def _cosSeries(c4s, sx, cx): # PYCHOK shared .geodesicx.gx and -.gxline 

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

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

69 ''' 

70 ar = _2cos2x(cx, sx) 

71 y0 = t0 = y1 = t1 = _0_0 

72 c4 = list(c4s) 

73 _c4 = c4.pop 

74 _s2 = _sum2_ 

75 if isodd(len(c4)): 

76 y0 = _c4() 

77 while c4: 

78 # y1 = ar * y0 - y1 + c4.pop() 

79 # y0 = ar * y1 - y0 + c4.pop() 

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

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

82 # s = cx * (y0 - y1) 

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

84 return s 

85 

86 

87_f = float # in _f2 and .geodesicx._C4_24, _27 and _30 

88 

89 

90def _f2(hi, lo): # in .geodesicx._C4_24, _27 and _30 

91 '''(INTERNAL) For C{_coeffs}. 

92 ''' 

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

94 

95 

96def _sincos12(sin1, cos1, sin2, cos2, sineg0=False): # PYCHOK shared 

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

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

99 

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

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

102 

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

104 

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

106 ''' 

107 s = sin2 * cos1 - sin1 * cos2 

108 c = cos2 * cos1 + sin1 * sin2 

109 if sineg0 and s < 0: 

110 s = _0_0 # max(s, _0_0) or NEG0? 

111 return s, c 

112 

113 

114def _sin1cos2(sin1, cos1, sin2, cos2): # PYCHOK shared 

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

116 

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

118 ''' 

119 s = sin1 * cos2 

120 c = _hypot(sin1 * sin2, cos1) 

121 return s, c # _norm2(s, c) 

122 

123 

124def _xnC4(**name_nC4): 

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

126 ''' 

127 n, nC4 = _xkwds_item2(name_nC4) 

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

129 raise GeodesicError(n, nC4, txt_not_=_or(*map(str, _nC4s))) 

130 return _nC4s[nC4] 

131 

132 

133# **) MIT License 

134# 

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

136# 

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

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

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

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

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

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

143# 

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

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

146# 

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

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

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

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

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

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

153# OTHER DEALINGS IN THE SOFTWARE.