def test_as_quantity():
from sympy.physics.unitsystems.quantities import Quantity
u = Unit(length, factor=10)
q = Quantity(10, Unit(length))
assert u.as_quantity == q
def test_div():
u = Unit(length, factor=10)
assert u.rdiv(1) == u.pow(-1)
assert u.div(1) == u
assert u.div(Unit(time, factor=2)) == Unit(length.div(time), factor=5)
assert u.div(Unit(length, factor=2)) == 5
def test_abbrev():
u = Unit(length)
assert u.abbrev == ""
u = Unit(length, abbrev="m")
assert u.abbrev == "m"
u = Unit(length, abbrev="m", prefix=k)
assert u.abbrev == "km"
def test_eq():
u = Unit(length, factor=10, abbrev="dm")
v = Unit(length, factor=10)
assert (u == v) is True
v = Unit(time, factor=10, abbrev="ds")
assert (u == v) is False
v = Unit(length, factor=1, abbrev="dm")
assert (u == v) is False
def test_call():
A = Unit(current)
Js = Unit(action)
mksa = UnitSystem((m, kg, s, A), (Js,))
assert mksa(Js) == mksa.print_unit_base(Js)
assert mksa(Js.dim) == mksa._system(Js.dim)
q = Quantity(10, Js)
assert mksa(q) == "%g %s" % (q.factor, mksa(Js))
def test_definition():
u = Unit(length, factor=10, abbrev="dm")
assert u.dim == length
assert u._factor == 10
assert u._abbrev == "dm"
assert u.prefix is None
km = Unit(length, prefix=k)
assert km.prefix == k
v = Unit(u, factor=5)
assert v.dim == length
assert v._factor == 5 * 10
def test_mul():
u = Unit(length, factor=10)
assert u.mul(1) == u
assert u.mul(Unit(time, factor=2)) == Unit(length.mul(time), factor=20)
assert u.mul(Unit(length.pow(-1), factor=2)) == 20
def prefix_unit(unit, prefixes):
"""
Return a list of all units formed by unit and the given prefixes.
You can use the predefined PREFIXES or BIN_PREFIXES, but you can also
pass as argument a subdict of them if you don't want all prefixed units.
>>> from sympy.physics.unitsystems.prefixes import (PREFIXES,
... prefix_unit)
>>> from sympy.physics.unitsystems.systems import mks
>>> m = mks["m"]
>>> pref = {"m": PREFIXES["m"], "c": PREFIXES["c"], "d": PREFIXES["d"]}
>>> prefix_unit(m, pref) #doctest: +SKIP
[cm, dm, mm]
"""
from sympy.physics.unitsystems.units import Unit
prefixed_units = []
for prefix in prefixes:
prefixed_units.append(
Unit(unit, abbrev=unit.abbrev, prefix=prefixes[prefix]))
return prefixed_units
def test_extend():
ms = UnitSystem((m, s), (c,))
Js = Unit(action)
mks = ms.extend((kg,), (Js,))
res = UnitSystem((m, s, kg), (c, Js))
assert set(mks._base_units) == set(res._base_units)
assert set(mks._units) == set(res._units)
def test_operations():
q = Quantity(10, m)
p = Quantity(5, s)
assert -q == Quantity(-10, m)
assert q.add(Quantity(20, m)) == Quantity(30, m)
assert q.add(Quantity(20, Unit(m.dim, 10))) == Quantity(30, Unit(m.dim, 11))
assert q.sub(Quantity(20, m)) == Quantity(-10, m)
assert q.sub(Quantity(20, Unit(m.dim, 10))) == Quantity(-10, Unit(m.dim, -9))
assert q.pow(2) == Quantity(10**2, m.pow(2))
assert q.mul(p) == Quantity(5*10, m.mul(s))
assert q.div(p) == Quantity(10/5, m.div(s))
def test_pow():
u = Unit(length, factor=10)
assert u.pow(0) == 1
assert u.pow(1) == u
assert u.pow(2) == Unit(length.pow(2), factor=100)
assert u.pow(-1) == Unit(length.pow(-1), factor=0.1)
def test_get_unit():
ms = UnitSystem((m, s), (c,))
assert ms.get_unit("s") == s
assert ms.get_unit(s) == s
assert ms.get_unit(Unit(time)) == s
assert ms["s"] == ms.get_unit("s")
raises(KeyError, lambda: ms["g"])
def test_definition():
# want to test if the system can have several units of the same dimension
dm = Unit(m, factor=0.1)
base = (m, s)
base_dim = (m.dim, s.dim)
ms = UnitSystem(base, (c, dm), "MS", "MS system")
assert set(ms._base_units) == set(base)
assert set(ms._units) == set((m, s, c, dm))
#assert ms._units == DimensionSystem._sort_dims(base + (velocity,))
assert ms.name == "MS"
assert ms.descr == "MS system"
assert ms._system._base_dims == DimensionSystem.sort_dims(base_dim)
assert set(ms._system._dims) == set(base_dim + (velocity,))
def test_add_sub():
u = Unit(length, factor=10)
v = Unit(length, factor=5)
w = Unit(time, factor=2)
assert u.add(v) == Unit(length, factor=15)
assert u.sub(v) == Unit(length, factor=5)
raises(ValueError, lambda: u.add(w))
raises(ValueError, lambda: u.sub(w))
raises(TypeError, lambda: u.add(1))
raises(TypeError, lambda: u.sub(1))
def test_repr():
u = Unit(length, factor=10, abbrev="m")
assert repr(u) == u.abbrev_dim
def test_str():
u = Unit(length, factor=10)
assert str(u) == u.abbrev_dim
u = Unit(length, factor=10, abbrev="m")
assert str(u) == "m"
def test_abbrev_dim():
u = Unit(length, factor=10)
assert u.abbrev_dim == "(10 L)"
def test_print_unit_base():
A = Unit(current)
Js = Unit(action)
mksa = UnitSystem((m, kg, s, A), (Js,))
assert mksa.print_unit_base(Js) == "0.001 m^2 kg s^-2"
def test_factor():
u = Unit(length, factor=10, abbrev="dm")
assert u.factor == 10
u = Unit(length, factor=5, prefix=k)
assert u.factor == 5000
def test_error_definition():
raises(TypeError, lambda: Unit("m"))
def test_is_compatible():
u = Unit(length, factor=10)
assert u.is_compatible(Unit(length)) is True
assert u.is_compatible(Unit(time)) is False
assert u.is_compatible(2) is False
def test_convert_to():
q = Quantity(5, Unit(m.dim, prefix=k))
assert q.convert_to(m) == Quantity(5000, m)
action = Dimension(name="action", symbol="A", length=2, mass=1, time=-1)
energy = Dimension(name="energy", symbol="E", length=2, mass=1, time=-2)
velocity = Dimension(name="velocity", symbol="V", length=1, time=-1)
# derived dimensions
length = Dimension(name="length", symbol="L", length=1)
mass = Dimension(name="mass", symbol="M", mass=1)
time = Dimension(name="time", symbol="T", time=1)
acceleration = Dimension(name="acceleration", length=1, time=-2)
momentum = Dimension(name="momentum", mass=1, length=1, time=-1)
force = Dimension(name="force", symbol="F", mass=1, length=1, time=-2)
power = Dimension(name="power", length=2, mass=1, time=-3)
frequency = Dimension(name="frequency", symbol="f", time=-1)
dims = (length, mass, time, momentum, force, energy, power, frequency)
# dimension system
natural_dim = DimensionSystem(base=(action, energy, velocity),
dims=dims,
name="Natural system")
# base units
hbar = Constant(action, factor=1.05457266e-34, abbrev="hbar")
eV = Unit(energy, factor=1.60219e-19, abbrev="eV")
c = Constant(velocity, factor=299792458, abbrev="c")
units = prefix_unit(eV, PREFIXES)
# unit system
natural = UnitSystem(base=(hbar, eV, c), units=units, name="Natural system")
charge = Dimension(name='charge', symbol='Q', current=1, time=1)
magnetic_density = Dimension(name='charge',
symbol='B',
mass=1,
current=-1,
time=-2)
magnetic_flux = Dimension(name='charge', length=2, mass=1, current=-1, time=-2)
dims = (voltage, impedance, conductance, capacitance, inductance, charge,
magnetic_density, magnetic_flux)
# dimension system
mksa_dim = mks_dim.extend(base=(current, ), dims=dims, name='MKSA')
# base units
A = Unit(current, abbrev='A')
# derived units
V = Unit(voltage, factor=10**3, abbrev='V')
ohm = Unit(impedance, factor=10**3, abbrev='ohm')
# siemens
S = Unit(conductance, factor=10**-3, abbrev='S')
# farad
F = Unit(capacitance, factor=10**-3, abbrev='F')
# henry
H = Unit(inductance, factor=10**3, abbrev='H')
# coulomb
C = Unit(charge, abbrev='C')
# tesla
T = Unit(magnetic_density, abbrev='T')
# weber
# -*- coding: utf-8 -*-
from sympy.physics.unitsystems.dimensions import Dimension, DimensionSystem
from sympy.physics.unitsystems.units import Unit, UnitSystem
from sympy.physics.unitsystems.quantities import Quantity
from sympy.utilities.pytest import raises
length = Dimension(name="length", symbol="L", length=1)
mass = Dimension(name="mass", symbol="M", mass=1)
time = Dimension(name="time", symbol="T", time=1)
current = Dimension(name="current", symbol="I", current=1)
velocity = Dimension(name="velocity", symbol="V", length=1, time=-1)
action = Dimension(name="action", symbol="A", length=2, mass=1, time=-2)
m = Unit(length, abbrev="m")
s = Unit(time, abbrev="s")
kg = Unit(mass, factor=10**3, abbrev="kg")
c = Unit(velocity, abbrev="c")
def test_definition():
# want to test if the system can have several units of the same dimension
dm = Unit(m, factor=0.1)
base = (m, s)
base_dim = (m.dim, s.dim)
ms = UnitSystem(base, (c, dm), "MS", "MS system")
assert set(ms._base_units) == set(base)
assert set(ms._units) == set((m, s, c, dm))
#assert ms._units == DimensionSystem._sort_dims(base + (velocity,))