def test_roundtrip_ogip(unit):
a = core.Unit(unit.to_string('ogip'), format='ogip')
assert_allclose(a.decompose().scale, unit.decompose().scale, rtol=1e-2)
try:
b = core.Unit(unit.decompose().to_string('ogip'), format='ogip')
except ValueError: # skip mag: decomposes into dex, unknown to OGIP
return
assert_allclose(b.decompose().scale, unit.decompose().scale, rtol=1e-2)
def test_roundtrip_vo_unit(unit):
a = core.Unit(unit.to_string('vounit'), format='vounit')
assert_allclose(a.decompose().scale, unit.decompose().scale, rtol=1e-2)
if unit not in (u.mag, u.dB):
ud = unit.decompose().to_string('vounit')
assert ' ' not in ud
b = core.Unit(ud, format='vounit')
assert_allclose(b.decompose().scale, unit.decompose().scale, rtol=1e-2)
def check_roundtrip(self, unit, output_format=None):
if output_format is None:
output_format = self.format_
with warnings.catch_warnings():
warnings.simplefilter('ignore') # Same warning shows up multiple times
s = unit.to_string(output_format)
if s in self.deprecated_units:
with pytest.warns(UnitsWarning, match='deprecated') as w:
a = core.Unit(s, format=self.format_)
assert len(w) == 1
else:
a = core.Unit(s, format=self.format_) # No warning
assert_allclose(a.decompose().scale, unit.decompose().scale, rtol=1e-9)
def test_roundtrip(self, unit):
if str(unit) in ('d', '0.001 Crab'):
# Special-case day, which gets auto-converted to hours, and mCrab,
# which the default check does not recognize as a deprecated unit.
with pytest.warns(UnitsWarning):
s = unit.to_string(self.format_)
a = core.Unit(s, format=self.format_)
assert_allclose(a.decompose().scale, unit.decompose().scale, rtol=1e-9)
else:
self.check_roundtrip(unit)
if str(unit) in ('mag', 'byte', 'Crab'):
# Skip mag and byte, which decompose into dex and bit, resp.,
# both of which are unknown to OGIP, as well as Crab, which does
# not decompose, and thus gives a deprecated unit warning.
return
power_of_ten = np.log10(unit.decompose().scale)
if abs(power_of_ten - round(power_of_ten)) > 1e-3:
ctx = pytest.warns(UnitsWarning, match='power of 10')
elif str(unit) == '0.001 Crab':
ctx = pytest.warns(UnitsWarning, match='deprecated')
else:
ctx = nullcontext()
with ctx:
self.check_roundtrip_decompose(unit)
def decompose_to_known_units(unit, func):
"""
Partially decomposes a unit so it is only composed of units that
are "known" to a given format.
Parameters
----------
unit : `~astropy.units.UnitBase` instance
func : callable
This function will be called to determine if a given unit is
"known". If the unit is not known, this function should raise a
`ValueError`.
Returns
-------
unit : `~astropy.units.UnitBase` instance
A flattened unit.
"""
from astropy.units import core
if isinstance(unit, core.CompositeUnit):
new_unit = core.Unit(unit.scale)
for base, power in zip(unit.bases, unit.powers):
new_unit = new_unit * decompose_to_known_units(base, func)**power
return new_unit
elif isinstance(unit, core.NamedUnit):
try:
func(unit)
except ValueError:
if isinstance(unit, core.Unit):
return decompose_to_known_units(unit._represents, func)
raise
return unit
def check_roundtrip(self, unit):
with catch_warnings() as w:
s = unit.to_string(self.format_)
a = core.Unit(s, format=self.format_)
if s in self.deprecated_units:
assert w
assert 'deprecated' in str(w[0])
else:
assert not w
assert_allclose(a.decompose().scale, unit.decompose().scale, rtol=1e-9)
def check_roundtrip(self, unit):
with pytest.warns(None) as w:
s = unit.to_string(self.format_)
a = core.Unit(s, format=self.format_)
if s in self.deprecated_units:
assert len(w) == 3 # Same warning shows up multiple times
for ww in w:
assert issubclass(ww.category, UnitsWarning)
assert 'deprecated' in str(ww.message)
else:
assert len(w) == 0
assert_allclose(a.decompose().scale, unit.decompose().scale, rtol=1e-9)
def test_roundtrip_fits(unit):
s = unit.to_string('fits')
a = core.Unit(s, format='fits')
assert_allclose(a.decompose().scale, unit.decompose().scale, rtol=1e-2)
def test_roundtrip(unit):
a = core.Unit(unit.to_string('generic'), format='generic')
b = core.Unit(unit.decompose().to_string('generic'), format='generic')
assert_allclose(a.decompose().scale, unit.decompose().scale, rtol=1e-2)
assert_allclose(b.decompose().scale, unit.decompose().scale, rtol=1e-2)
def check_roundtrip_decompose(self, unit):
ud = unit.decompose()
s = ud.to_string(self.format_)
assert ' ' not in s
a = core.Unit(s, format=self.format_)
assert_allclose(a.decompose().scale, ud.scale, rtol=1e-5)