def test_good_named_sub():
"""Two quantities with the same named complex units should sub together"""
furlong = unit('fur')
assert (Quantity(4, furlong) - Quantity(2, furlong) == Quantity(
2, furlong))
def test_divide_named_scalar():
"""Named quantities / scalars"""
m_per_s = NamedComposedUnit('vel',
unit('m') / unit('s'))
assert (Quantity(8, m_per_s) / 2 ==
Quantity(4, m_per_s))
def test_valid_composed_to_basic():
"""Composed units should convert to basic equivalents."""
metre = unit('m')
hundred_cm_in_metres = metre(Quantity(100, unit('cm')))
assert hundred_cm_in_metres == Quantity(1.0, metre)
assert str(hundred_cm_in_metres) == '1.00 m'
def test_valid_basic_to_composed():
"""Test conversion to composed units."""
composed_cm = unit('cm').composed_unit
one_m_in_cm = composed_cm(Quantity(1, unit('m')))
assert one_m_in_cm == Quantity(1, unit('m'))
def test_rmultiply_named_scalar():
"""Scalars * Named quantities"""
m_per_s = NamedComposedUnit('vel',
unit('m') / unit('s'))
assert (2 * Quantity(8, m_per_s) ==
Quantity(16, m_per_s))
def test_multiply_named_scalar():
"""Named quantities * scalars"""
m_per_s = NamedComposedUnit('vel',
unit('m') / unit('s'))
assert (Quantity(8, m_per_s) * 2 ==
Quantity(16, m_per_s))
def test_rdivide_named_scalar():
"""Scalars / Named quantities"""
m_per_s = NamedComposedUnit('vel',
unit('m') / unit('s'))
assert (4 / Quantity(2, m_per_s) ==
Quantity(2, unit('s') / unit('m')))
def test_valid_named_to_composed():
"""Named units should convert to the composed equivalents."""
hertz = unit('Hz')
one_hz_in_per_second = hertz.composed_unit(Quantity(1, hertz))
assert one_hz_in_per_second == Quantity(1, hertz)
assert str(one_hz_in_per_second) == '1.00 1 / s'
def test_valid_basic_to_named():
"""Basic units should convert into named equivalents."""
metre = unit('m')
thousand_m_in_km = unit('km')(Quantity(1000, metre))
assert thousand_m_in_km == Quantity(1, unit('km'))
assert thousand_m_in_km.unit == unit('km')
assert str(thousand_m_in_km) == '1.00 km'
def test_valid_composed_to_named():
"""Composed units should convert to named equivalents."""
hertz = unit('Hz')
per_second = hertz.composed_unit
one_hz = hertz(Quantity(1, per_second))
assert one_hz == Quantity(1, hertz)
assert str(one_hz) == '1.00 Hz'
def test_valid_named_to_basic():
"""Named units should convert to their basic equivalents"""
kilometre = unit('km')
one_km_in_m = unit('m')(Quantity(1, kilometre))
assert one_km_in_m == Quantity(1000, unit('m'))
assert one_km_in_m.unit == unit('m')
assert str(one_km_in_m) == '1000.00 m'
def test_good_composed_add():
"""Two quantities with the same complex units should add together"""
assert (Quantity(2,
unit('m') / unit('s')) +
Quantity(3,
unit('m') / unit('s')) == Quantity(
5,
unit('m') / unit('s')))
def test_valid_named_to_named():
"""Named units should convert to named equivalents."""
gray = unit('Gy')
sievert = unit('Sv')
one_gray_in_sievert = sievert(Quantity(1, gray))
assert one_gray_in_sievert == Quantity(1, gray)
assert str(one_gray_in_sievert) == '1.00 Sv'
def test_volume():
"""Volume units should interchange correctly with cubed area units."""
litres = unit('L')
millilitres = unit('mL')
centimetres = unit('cm')
cm_cubed = centimetres * centimetres * centimetres
assert Quantity(1, litres) == Quantity(1000, millilitres)
assert Quantity(1, millilitres) == Quantity(1, cm_cubed)
def __call__(self, quantity):
"""Overload the function call operator to convert units."""
if not hasattr(quantity, 'unit'):
return Quantity(quantity, self)
elif compatible(self, quantity.unit):
return Quantity(
quantity.num * quantity.unit.squeeze() / self.squeeze(), self)
else:
raise IncompatibleUnitsError()
def test_good_named_add():
"""Two quantities with the same named complex units should add together"""
furlong = NamedComposedUnit('furlong',
ComposedUnit([unit('m')], [],
multiplier=201.168),
is_si=False)
assert (Quantity(2, furlong) + Quantity(2, furlong) == Quantity(
4, furlong))
def translate(self, source_quantity, target_unit=None):
if not isinstance(source_quantity, Quantity):
source_quantity = Quantity(source_quantity, self.source_unit)
target_unit = target_unit or self.target_unit
converter_source_quantity = strict_convert_to_unit(
source_quantity, self.source_unit)
converter_target_quantity = Quantity(
self.forward_converter(converter_source_quantity),
self.target_unit)
target_quantity = strict_convert_to_unit(converter_target_quantity,
target_unit)
return target_quantity
def test_valid_composed_to_composed():
"""Valid composed units in terms of others."""
metric_vel = unit('km') / unit('h')
imp_vel = unit('mi') / unit('h')
highway_kph = Quantity(100, metric_vel)
highway_mph = Quantity(62.1371192237334, imp_vel)
assert str(highway_kph) == '100.00 km / h'
assert str(highway_mph) == '62.14 mi / h'
assert within_epsilon(imp_vel(highway_kph), highway_mph)
assert str(imp_vel(highway_kph)) == '62.14 mi / h'
def test_good_add_w_mults():
"""Two quantities with compatible units should add together
even when they have different multipliers"""
mile = ComposedUnit([unit('m')], [], multiplier=1609.344)
kilometre = ComposedUnit([unit('m')], [], multiplier=1000)
m_on_left = Quantity(1, mile) + Quantity(1, kilometre)
km_on_left = Quantity(1, kilometre) + Quantity(1, mile)
manual_sum = Quantity(2609.344, unit('m'))
assert within_epsilon(m_on_left, km_on_left)
assert within_epsilon(km_on_left, m_on_left)
assert within_epsilon(manual_sum, m_on_left)
assert within_epsilon(manual_sum, km_on_left)
assert within_epsilon(m_on_left, manual_sum)
assert within_epsilon(km_on_left, manual_sum)
def test_pow():
"""Exponentiation of quantities."""
REGISTRY.clear()
define_units()
m_unit = unit('m')
m_quant = Quantity(2, m_unit)
assert (m_quant ** 2 ==
m_quant * m_quant ==
pow(m_quant, 2))
cm_unit = unit('cm')
cm_quant = Quantity(2, cm_unit)
assert within_epsilon(cm_quant ** 2, cm_quant * cm_quant)
assert within_epsilon(cm_quant ** 2, pow(cm_quant, 2))
def test_good_mixed_sub():
"""Two quantities with the same units should sub together
even if one is named"""
gray = unit('Gy')
sievert = unit('Sv').composed_unit
assert (Quantity(4, gray) - Quantity(2, sievert) == Quantity(2, gray))
assert (Quantity(4, sievert) - Quantity(2, gray) == Quantity(2, sievert))
assert Quantity(2, sievert) == Quantity(2, gray)
def test_good_sub_w_mult():
"""Two quantities with same units should sub together when
they have the same multiplier"""
moon = ComposedUnit([unit('day')], [], multiplier=28)
lunar_cycle = ComposedUnit([unit('day')], [], multiplier=28)
assert (Quantity(2, moon) - Quantity(1, lunar_cycle) == Quantity(1, moon))
assert (Quantity(2, lunar_cycle) - Quantity(1, moon) == Quantity(
1, lunar_cycle))
assert Quantity(1, moon) == Quantity(1, lunar_cycle)
def test_good_mixed_add():
"""Two quantities with the same units should add together
even if one is named"""
gray = NamedComposedUnit('gray',
ComposedUnit([unit('J'), unit('kg')], []),
is_si=True)
sievert = ComposedUnit([unit('J'), unit('kg')], [])
assert (Quantity(2, gray) + Quantity(2, sievert) == Quantity(4, gray))
assert (Quantity(2, sievert) + Quantity(2, gray) == Quantity(4, sievert))
assert Quantity(2, sievert) == Quantity(2, gray)
def test_good_named_add_w_mults():
"""Two quantities with compatible but differently-named and
differently-multiplied units should add together."""
mile = unit('mi')
kilometre = unit('km')
assert within_epsilon(
Quantity(1, mile) + Quantity(1, kilometre),
Quantity(1, kilometre) + Quantity(1, mile))
assert within_epsilon(Quantity(2609.344, unit('m')),
Quantity(1, kilometre) + Quantity(1, mile))
def test_good_named_add_w_mult():
"""A quantity with a named composed unit that carries a multiplier
should add to a composed unit that has a multiplier"""
mile = unit('mi').composed_unit
kilometre = unit('km')
assert within_epsilon(
Quantity(1, mile) + Quantity(1, kilometre),
Quantity(1, kilometre) + Quantity(1, mile))
assert within_epsilon(Quantity(2609.344, unit('m')),
Quantity(1, kilometre) + Quantity(1, mile))
def test_simple_multiply_quantity():
"""Simple multiplication of quantities"""
assert (Quantity(2, unit('m')) *
Quantity(2, unit('s')) ==
Quantity(4, unit('m') * unit('s')))
assert (Quantity(2, unit('s')) *
Quantity(2, unit('m')) ==
Quantity(4, unit('m') * unit('s')))
def test_good_sub_w_mults():
"""Two quantities with compatible units should sub together
even when they have different multipliers"""
mile = unit('mi').composed_unit
kilometre = unit('km').composed_unit
m_on_left = Quantity(1, mile) - Quantity(1, kilometre)
km_on_left = Quantity(1, kilometre) - Quantity(1, mile)
m_on_left_diff = Quantity(609.344, unit('m'))
km_on_left_diff = Quantity(-609.344, unit('m'))
assert within_epsilon(m_on_left, m_on_left_diff)
assert within_epsilon(km_on_left, km_on_left_diff)
assert within_epsilon(m_on_left_diff, -km_on_left_diff)
def subtract_bad():
"""Incompatible leaf units should not subtract from one another."""
metres = Quantity(2, unit('m'))
seconds = Quantity(2, unit('s'))
return metres - seconds
def test_good_simple_sub():
"""Should be able to subtract compatible Quantities."""
assert (Quantity(4, unit('m')) - Quantity(2, unit('m')) == Quantity(
2, unit('m')))
def add_bad():
"""Incompatible leaf units should not add together."""
metres = Quantity(2, unit('m'))
seconds = Quantity(2, unit('s'))
return metres + seconds