Coverage for tests/test_time_utils.py: 15%
75 statements
« prev ^ index » next coverage.py v7.2.5, created at 2023-05-09 02:11 -0700
« prev ^ index » next coverage.py v7.2.5, created at 2023-05-09 02:11 -0700
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/>.
22"""Unit tests for methods in butler.time module.
23"""
25import unittest
26import warnings
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
35import astropy.utils.exceptions
36from astropy.time import Time, TimeDelta
37from lsst.daf.butler.core.time_utils import TimeConverter
40class TimeTestCase(unittest.TestCase):
41 """A test case for time module"""
43 def test_time_before_epoch(self):
44 """Tests for before-the-epoch time."""
45 time = Time("1950-01-01T00:00:00", format="isot", scale="tai")
46 value = TimeConverter().astropy_to_nsec(time)
47 self.assertEqual(value, 0)
49 value = TimeConverter().nsec_to_astropy(value)
50 self.assertEqual(value, TimeConverter().epoch)
52 def test_max_time(self):
53 """Tests for after-the-end-of-astronomy time."""
54 # there are rounding issues, need more complex comparison
55 time = Time("2101-01-01T00:00:00", format="isot", scale="tai")
56 value = TimeConverter().astropy_to_nsec(time)
58 value_max = TimeConverter().astropy_to_nsec(TimeConverter().max_time)
59 self.assertEqual(value, value_max)
61 # Astropy will give "dubious year" for UTC five years in the future
62 # so hide these expected warnings from the test output
63 with warnings.catch_warnings():
64 warnings.simplefilter("ignore", category=astropy.utils.exceptions.AstropyWarning)
65 if erfa is not None:
66 warnings.simplefilter("ignore", category=erfa.ErfaWarning)
67 time = Time("2101-01-01T00:00:00", format="isot", scale="utc")
69 # unittest can't test for no warnings so we run the test and
70 # trigger our own warning and count all the warnings
71 with self.assertWarns(Warning) as cm:
72 TimeConverter().astropy_to_nsec(time)
73 warnings.warn("deliberate")
74 self.assertEqual(str(cm.warning), "deliberate")
76 def test_round_trip(self):
77 """Test precision of round-trip conversion."""
78 # do tests at random points between epoch and max. time
79 times = [
80 "1970-01-01T12:00:00.123",
81 "1999-12-31T23:59:57.123456",
82 "2000-01-01T12:00:00.123456",
83 "2030-01-01T12:00:00.123456789",
84 "2075-08-17T00:03:45",
85 "2099-12-31T23:00:50",
86 ]
87 for time in times:
88 atime = Time(time, format="isot", scale="tai")
89 for sec in range(7):
90 # loop over few seconds to add to each time
91 for i in range(100):
92 # loop over additional fractions of seconds
93 delta = sec + 0.3e-9 * i
94 in_time = atime + TimeDelta(delta, format="sec")
95 # do round-trip conversion to nsec and back
96 value = TimeConverter().astropy_to_nsec(in_time)
97 value = TimeConverter().nsec_to_astropy(value)
98 delta2 = value - in_time
99 delta2_sec = delta2.to_value("sec")
100 # absolute precision should be better than half
101 # nanosecond, but there are rounding errors too
102 self.assertLess(abs(delta2_sec), 0.51e-9)
104 def test_times_equal(self):
105 """Test for times_equal method"""
106 # time == time should always work
107 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="tai")
108 self.assertTrue(TimeConverter().times_equal(time1, time1))
110 # one nsec difference
111 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="tai")
112 time2 = Time("2000-01-01T00:00:00.123456788", format="isot", scale="tai")
113 self.assertTrue(TimeConverter().times_equal(time1, time2, 2.0))
114 self.assertTrue(TimeConverter().times_equal(time2, time1, 2.0))
115 self.assertFalse(TimeConverter().times_equal(time1, time2, 0.5))
116 self.assertFalse(TimeConverter().times_equal(time2, time1, 0.5))
118 # one nsec difference, times in UTC
119 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="utc")
120 time2 = Time("2000-01-01T00:00:00.123456788", format="isot", scale="utc")
121 self.assertTrue(TimeConverter().times_equal(time1, time2, 2.0))
122 self.assertTrue(TimeConverter().times_equal(time2, time1, 2.0))
123 self.assertFalse(TimeConverter().times_equal(time1, time2, 0.5))
124 self.assertFalse(TimeConverter().times_equal(time2, time1, 0.5))
126 # 1/2 nsec difference
127 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="tai")
128 time2 = time1 + TimeDelta(0.5e-9, format="sec")
129 self.assertTrue(TimeConverter().times_equal(time1, time2))
130 self.assertTrue(TimeConverter().times_equal(time2, time1))
131 self.assertFalse(TimeConverter().times_equal(time1, time2, 0.25))
132 self.assertFalse(TimeConverter().times_equal(time2, time1, 0.25))
134 # 1/2 microsec difference
135 time1 = Time("2000-01-01T00:00:00.123456789", format="isot", scale="tai")
136 time2 = time1 + TimeDelta(0.5e-6, format="sec")
137 self.assertTrue(TimeConverter().times_equal(time1, time2, 501))
138 self.assertTrue(TimeConverter().times_equal(time2, time1, 501))
139 self.assertFalse(TimeConverter().times_equal(time1, time2, 499))
140 self.assertFalse(TimeConverter().times_equal(time2, time1, 499))
142 # UTC vs TAI
143 time1 = Time("2013-06-17 13:34:45.775000", scale="tai", format="iso")
144 time2 = Time("2013-06-17T13:34:10.775", scale="utc", format="isot")
145 self.assertTrue(TimeConverter().times_equal(time1, time2))
146 self.assertEqual(TimeConverter().astropy_to_nsec(time1), TimeConverter().astropy_to_nsec(time2))
149if __name__ == "__main__":
150 unittest.main()