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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 

28import astropy.utils.exceptions 

29from astropy.time import Time, TimeDelta 

30from lsst.daf.butler.core.time_utils import TimeConverter 

31 

32 

33class TimeTestCase(unittest.TestCase): 

34 """A test case for time module 

35 """ 

36 

37 def test_time_before_epoch(self): 

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

39 """ 

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

41 value = TimeConverter().astropy_to_nsec(time) 

42 self.assertEqual(value, 0) 

43 

44 value = TimeConverter().nsec_to_astropy(value) 

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

46 

47 def test_max_time(self): 

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

49 """ 

50 # there are rounding issues, need more complex comparison 

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

52 value = TimeConverter().astropy_to_nsec(time) 

53 

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

55 self.assertEqual(value, value_max) 

56 

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

58 # so hide these expected warnings from the test output 

59 with warnings.catch_warnings(): 

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

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

62 

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

64 # trigger our own warning and count all the warnings 

65 with self.assertWarns(Warning) as cm: 

66 TimeConverter().astropy_to_nsec(time) 

67 warnings.warn("deliberate") 

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

69 

70 def test_round_trip(self): 

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

72 """ 

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

74 times = [ 

75 "1970-01-01T12:00:00.123", 

76 "1999-12-31T23:59:57.123456", 

77 "2000-01-01T12:00:00.123456", 

78 "2030-01-01T12:00:00.123456789", 

79 "2075-08-17T00:03:45", 

80 "2099-12-31T23:00:50", 

81 ] 

82 for time in times: 

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

84 for sec in range(7): 

85 # loop over few seconds to add to each time 

86 for i in range(100): 

87 # loop over additional fractions of seconds 

88 delta = sec + 0.3e-9 * i 

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

90 # do round-trip conversion to nsec and back 

91 value = TimeConverter().astropy_to_nsec(in_time) 

92 value = TimeConverter().nsec_to_astropy(value) 

93 delta2 = value - in_time 

94 delta2_sec = delta2.to_value("sec") 

95 # absolute precision should be better than half 

96 # nanosecond, but there are rounding errors too 

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

98 

99 def test_times_equal(self): 

100 """Test for times_equal method 

101 """ 

102 # time == time should always work 

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

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

105 

106 # one nsec difference 

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

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

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

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

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

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

113 

114 # one nsec difference, times in UTC 

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

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

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

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

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

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

121 

122 # 1/2 nsec difference 

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

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

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

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

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

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

129 

130 # 1/2 microsec difference 

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

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

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

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

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

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

137 

138 # UTC vs TAI 

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

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

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

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

143 

144 

145if __name__ == "__main__": 145 ↛ 146line 145 didn't jump to line 146, because the condition on line 145 was never true

146 unittest.main()