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1# This file is part of daf_butler. 

2# 

3# Developed for the LSST Data Management System. 

4# This product includes software developed by the LSST Project 

5# (https://www.lsst.org). 

6# See the COPYRIGHT file at the top-level directory of this distribution 

7# for details of code ownership. 

8# 

9# This program is free software: you can redistribute it and/or modify 

10# it under the terms of the GNU General Public License as published by 

11# the Free Software Foundation, either version 3 of the License, or 

12# (at your option) any later version. 

13# 

14# This program is distributed in the hope that it will be useful, 

15# but WITHOUT ANY WARRANTY; without even the implied warranty of 

16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

17# GNU General Public License for more details. 

18# 

19# You should have received a copy of the GNU General Public License 

20# along with this program. If not, see <https://www.gnu.org/licenses/>. 

21 

22"""Unit tests for methods in butler.time module. 

23""" 

24 

25import unittest 

26import warnings 

27 

28# As of astropy 4.2, the erfa interface is shipped independently and 

29# ErfaWarning is no longer an AstropyWarning 

30try: 

31 import erfa 

32except ImportError: 

33 erfa = None 

34 

35import astropy.utils.exceptions 

36from astropy.time import Time, TimeDelta 

37from lsst.daf.butler.core.time_utils import TimeConverter 

38 

39 

40class TimeTestCase(unittest.TestCase): 

41 """A test case for time module 

42 """ 

43 

44 def test_time_before_epoch(self): 

45 """Tests for before-the-epoch time. 

46 """ 

47 time = Time("1950-01-01T00:00:00", format="isot", scale="tai") 

48 value = TimeConverter().astropy_to_nsec(time) 

49 self.assertEqual(value, 0) 

50 

51 value = TimeConverter().nsec_to_astropy(value) 

52 self.assertEqual(value, TimeConverter().epoch) 

53 

54 def test_max_time(self): 

55 """Tests for after-the-end-of-astronomy time. 

56 """ 

57 # there are rounding issues, need more complex comparison 

58 time = Time("2101-01-01T00:00:00", format="isot", scale="tai") 

59 value = TimeConverter().astropy_to_nsec(time) 

60 

61 value_max = TimeConverter().astropy_to_nsec(TimeConverter().max_time) 

62 self.assertEqual(value, value_max) 

63 

64 # Astropy will give "dubious year" for UTC five years in the future 

65 # so hide these expected warnings from the test output 

66 with warnings.catch_warnings(): 

67 warnings.simplefilter("ignore", category=astropy.utils.exceptions.AstropyWarning) 

68 if erfa is not None: 

69 warnings.simplefilter("ignore", category=erfa.ErfaWarning) 

70 time = Time("2101-01-01T00:00:00", format="isot", scale="utc") 

71 

72 # unittest can't test for no warnings so we run the test and 

73 # trigger our own warning and count all the warnings 

74 with self.assertWarns(Warning) as cm: 

75 TimeConverter().astropy_to_nsec(time) 

76 warnings.warn("deliberate") 

77 self.assertEqual(str(cm.warning), "deliberate") 

78 

79 def test_round_trip(self): 

80 """Test precision of round-trip conversion. 

81 """ 

82 # do tests at random points between epoch and max. time 

83 times = [ 

84 "1970-01-01T12:00:00.123", 

85 "1999-12-31T23:59:57.123456", 

86 "2000-01-01T12:00:00.123456", 

87 "2030-01-01T12:00:00.123456789", 

88 "2075-08-17T00:03:45", 

89 "2099-12-31T23:00:50", 

90 ] 

91 for time in times: 

92 atime = Time(time, format="isot", scale="tai") 

93 for sec in range(7): 

94 # loop over few seconds to add to each time 

95 for i in range(100): 

96 # loop over additional fractions of seconds 

97 delta = sec + 0.3e-9 * i 

98 in_time = atime + TimeDelta(delta, format="sec") 

99 # do round-trip conversion to nsec and back 

100 value = TimeConverter().astropy_to_nsec(in_time) 

101 value = TimeConverter().nsec_to_astropy(value) 

102 delta2 = value - in_time 

103 delta2_sec = delta2.to_value("sec") 

104 # absolute precision should be better than half 

105 # nanosecond, but there are rounding errors too 

106 self.assertLess(abs(delta2_sec), 0.51e-9) 

107 

108 def test_times_equal(self): 

109 """Test for times_equal method 

110 """ 

111 # time == time should always work 

112 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="tai") 

113 self.assertTrue(TimeConverter().times_equal(time1, time1)) 

114 

115 # one nsec difference 

116 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="tai") 

117 time2 = Time("2000-01-01T00:00:00.123456788", format="isot", scale="tai") 

118 self.assertTrue(TimeConverter().times_equal(time1, time2, 2.)) 

119 self.assertTrue(TimeConverter().times_equal(time2, time1, 2.)) 

120 self.assertFalse(TimeConverter().times_equal(time1, time2, .5)) 

121 self.assertFalse(TimeConverter().times_equal(time2, time1, .5)) 

122 

123 # one nsec difference, times in UTC 

124 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="utc") 

125 time2 = Time("2000-01-01T00:00:00.123456788", format="isot", scale="utc") 

126 self.assertTrue(TimeConverter().times_equal(time1, time2, 2.)) 

127 self.assertTrue(TimeConverter().times_equal(time2, time1, 2.)) 

128 self.assertFalse(TimeConverter().times_equal(time1, time2, .5)) 

129 self.assertFalse(TimeConverter().times_equal(time2, time1, .5)) 

130 

131 # 1/2 nsec difference 

132 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="tai") 

133 time2 = time1 + TimeDelta(0.5e-9, format="sec") 

134 self.assertTrue(TimeConverter().times_equal(time1, time2)) 

135 self.assertTrue(TimeConverter().times_equal(time2, time1)) 

136 self.assertFalse(TimeConverter().times_equal(time1, time2, .25)) 

137 self.assertFalse(TimeConverter().times_equal(time2, time1, .25)) 

138 

139 # 1/2 microsec difference 

140 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="tai") 

141 time2 = time1 + TimeDelta(0.5e-6, format="sec") 

142 self.assertTrue(TimeConverter().times_equal(time1, time2, 501)) 

143 self.assertTrue(TimeConverter().times_equal(time2, time1, 501)) 

144 self.assertFalse(TimeConverter().times_equal(time1, time2, 499)) 

145 self.assertFalse(TimeConverter().times_equal(time2, time1, 499)) 

146 

147 # UTC vs TAI 

148 time1 = Time('2013-06-17 13:34:45.775000', scale='tai', format='iso') 

149 time2 = Time('2013-06-17T13:34:10.775', scale='utc', format='isot') 

150 self.assertTrue(TimeConverter().times_equal(time1, time2)) 

151 self.assertEqual(TimeConverter().astropy_to_nsec(time1), TimeConverter().astropy_to_nsec(time2)) 

152 

153 

154if __name__ == "__main__": 154 ↛ 155line 154 didn't jump to line 155, because the condition on line 154 was never true

155 unittest.main()