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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 

26 

27from astropy.time import Time, TimeDelta 

28from lsst.daf.butler import time_utils 

29 

30 

31class TimeTestCase(unittest.TestCase): 

32 """A test case for time module 

33 """ 

34 

35 def test_time_before_epoch(self): 

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

37 """ 

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

39 value = time_utils.astropy_to_nsec(time) 

40 self.assertEqual(value, 0) 

41 

42 value = time_utils.nsec_to_astropy(value) 

43 self.assertEqual(value, time_utils.EPOCH) 

44 

45 def test_max_time(self): 

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

47 """ 

48 # there are rounding issues, need more complex comparison 

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

50 value = time_utils.astropy_to_nsec(time) 

51 

52 value_max = time_utils.astropy_to_nsec(time_utils.MAX_TIME) 

53 self.assertEqual(value, value_max) 

54 

55 def test_round_trip(self): 

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

57 """ 

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

59 times = [ 

60 "1970-01-01T12:00:00.123", 

61 "1999-12-31T23:59:57.123456", 

62 "2000-01-01T12:00:00.123456", 

63 "2030-01-01T12:00:00.123456789", 

64 "2075-08-17T00:03:45", 

65 "2099-12-31T23:00:50", 

66 ] 

67 for time in times: 

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

69 for sec in range(7): 

70 # loop over few seconds to add to each time 

71 for i in range(100): 

72 # loop over additional fractions of seconds 

73 delta = sec + 0.3e-9 * i 

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

75 # do round-trip conversion to nsec and back 

76 value = time_utils.astropy_to_nsec(in_time) 

77 value = time_utils.nsec_to_astropy(value) 

78 delta2 = value - in_time 

79 delta2_sec = delta2.to_value("sec") 

80 # absolute precision should be better than half 

81 # nanosecond, but there are rounding errors too 

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

83 

84 def test_times_equal(self): 

85 """Test for times_equal method 

86 """ 

87 # time == time should always work 

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

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

90 

91 # one nsec difference 

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

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

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

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

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

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

98 

99 # one nsec difference, times in UTC 

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

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

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

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

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

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

106 

107 # 1/2 nsec difference 

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

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

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

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

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

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

114 

115 # 1/2 microsec difference 

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

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

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

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

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

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

122 

123 

124if __name__ == "__main__": 124 ↛ 125line 124 didn't jump to line 125, because the condition on line 124 was never true

125 unittest.main()