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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 import time_utils 

31from lsst.daf.butler.core.time_utils import astropy_to_nsec 

32 

33 

34class TimeTestCase(unittest.TestCase): 

35 """A test case for time module 

36 """ 

37 

38 def test_time_before_epoch(self): 

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

40 """ 

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

42 value = time_utils.astropy_to_nsec(time) 

43 self.assertEqual(value, 0) 

44 

45 value = time_utils.nsec_to_astropy(value) 

46 self.assertEqual(value, time_utils.EPOCH) 

47 

48 def test_max_time(self): 

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

50 """ 

51 # there are rounding issues, need more complex comparison 

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

53 value = time_utils.astropy_to_nsec(time) 

54 

55 value_max = time_utils.astropy_to_nsec(time_utils.MAX_TIME) 

56 self.assertEqual(value, value_max) 

57 

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

59 # so hide these expected warnings from the test output 

60 with warnings.catch_warnings(): 

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

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

63 

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

65 # trigger our own warning and count all the warnings 

66 with self.assertWarns(Warning) as cm: 

67 time_utils.astropy_to_nsec(time) 

68 warnings.warn("deliberate") 

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

70 

71 def test_round_trip(self): 

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

73 """ 

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

75 times = [ 

76 "1970-01-01T12:00:00.123", 

77 "1999-12-31T23:59:57.123456", 

78 "2000-01-01T12:00:00.123456", 

79 "2030-01-01T12:00:00.123456789", 

80 "2075-08-17T00:03:45", 

81 "2099-12-31T23:00:50", 

82 ] 

83 for time in times: 

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

85 for sec in range(7): 

86 # loop over few seconds to add to each time 

87 for i in range(100): 

88 # loop over additional fractions of seconds 

89 delta = sec + 0.3e-9 * i 

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

91 # do round-trip conversion to nsec and back 

92 value = time_utils.astropy_to_nsec(in_time) 

93 value = time_utils.nsec_to_astropy(value) 

94 delta2 = value - in_time 

95 delta2_sec = delta2.to_value("sec") 

96 # absolute precision should be better than half 

97 # nanosecond, but there are rounding errors too 

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

99 

100 def test_times_equal(self): 

101 """Test for times_equal method 

102 """ 

103 # time == time should always work 

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

105 self.assertTrue(time_utils.times_equal(time1, time1)) 

106 

107 # one nsec difference 

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

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

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

111 self.assertTrue(time_utils.times_equal(time2, time1, 2.)) 

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

113 self.assertFalse(time_utils.times_equal(time2, time1, .5)) 

114 

115 # one nsec difference, times in UTC 

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

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

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

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

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

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

122 

123 # 1/2 nsec difference 

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

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

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

127 self.assertTrue(time_utils.times_equal(time2, time1)) 

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

129 self.assertFalse(time_utils.times_equal(time2, time1, .25)) 

130 

131 # 1/2 microsec difference 

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

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

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

135 self.assertTrue(time_utils.times_equal(time2, time1, 501)) 

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

137 self.assertFalse(time_utils.times_equal(time2, time1, 499)) 

138 

139 # UTC vs TAI 

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

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

142 self.assertTrue(time_utils.times_equal(time1, time2)) 

143 self.assertEqual(astropy_to_nsec(time1), astropy_to_nsec(time2)) 

144 

145 

146if __name__ == "__main__": 146 ↛ 147line 146 didn't jump to line 147, because the condition on line 146 was never true

147 unittest.main()