ai-content-maker/.venv/Lib/site-packages/sympy/physics/units/tests/test_quantities.py

582 lines
20 KiB
Python

import warnings
from sympy.core.add import Add
from sympy.core.function import (Function, diff)
from sympy.core.numbers import (Number, Rational)
from sympy.core.singleton import S
from sympy.core.symbol import (Symbol, symbols)
from sympy.functions.elementary.complexes import Abs
from sympy.functions.elementary.exponential import (exp, log)
from sympy.functions.elementary.miscellaneous import sqrt
from sympy.functions.elementary.trigonometric import sin
from sympy.integrals.integrals import integrate
from sympy.physics.units import (amount_of_substance, area, convert_to, find_unit,
volume, kilometer, joule, molar_gas_constant,
vacuum_permittivity, elementary_charge, volt,
ohm)
from sympy.physics.units.definitions import (amu, au, centimeter, coulomb,
day, foot, grams, hour, inch, kg, km, m, meter, millimeter,
minute, quart, s, second, speed_of_light, bit,
byte, kibibyte, mebibyte, gibibyte, tebibyte, pebibyte, exbibyte,
kilogram, gravitational_constant, electron_rest_mass)
from sympy.physics.units.definitions.dimension_definitions import (
Dimension, charge, length, time, temperature, pressure,
energy, mass
)
from sympy.physics.units.prefixes import PREFIXES, kilo
from sympy.physics.units.quantities import PhysicalConstant, Quantity
from sympy.physics.units.systems import SI
from sympy.testing.pytest import raises
k = PREFIXES["k"]
def test_str_repr():
assert str(kg) == "kilogram"
def test_eq():
# simple test
assert 10*m == 10*m
assert 10*m != 10*s
def test_convert_to():
q = Quantity("q1")
q.set_global_relative_scale_factor(S(5000), meter)
assert q.convert_to(m) == 5000*m
assert speed_of_light.convert_to(m / s) == 299792458 * m / s
# TODO: eventually support this kind of conversion:
# assert (2*speed_of_light).convert_to(m / s) == 2 * 299792458 * m / s
assert day.convert_to(s) == 86400*s
# Wrong dimension to convert:
assert q.convert_to(s) == q
assert speed_of_light.convert_to(m) == speed_of_light
expr = joule*second
conv = convert_to(expr, joule)
assert conv == joule*second
def test_Quantity_definition():
q = Quantity("s10", abbrev="sabbr")
q.set_global_relative_scale_factor(10, second)
u = Quantity("u", abbrev="dam")
u.set_global_relative_scale_factor(10, meter)
km = Quantity("km")
km.set_global_relative_scale_factor(kilo, meter)
v = Quantity("u")
v.set_global_relative_scale_factor(5*kilo, meter)
assert q.scale_factor == 10
assert q.dimension == time
assert q.abbrev == Symbol("sabbr")
assert u.dimension == length
assert u.scale_factor == 10
assert u.abbrev == Symbol("dam")
assert km.scale_factor == 1000
assert km.func(*km.args) == km
assert km.func(*km.args).args == km.args
assert v.dimension == length
assert v.scale_factor == 5000
def test_abbrev():
u = Quantity("u")
u.set_global_relative_scale_factor(S.One, meter)
assert u.name == Symbol("u")
assert u.abbrev == Symbol("u")
u = Quantity("u", abbrev="om")
u.set_global_relative_scale_factor(S(2), meter)
assert u.name == Symbol("u")
assert u.abbrev == Symbol("om")
assert u.scale_factor == 2
assert isinstance(u.scale_factor, Number)
u = Quantity("u", abbrev="ikm")
u.set_global_relative_scale_factor(3*kilo, meter)
assert u.abbrev == Symbol("ikm")
assert u.scale_factor == 3000
def test_print():
u = Quantity("unitname", abbrev="dam")
assert repr(u) == "unitname"
assert str(u) == "unitname"
def test_Quantity_eq():
u = Quantity("u", abbrev="dam")
v = Quantity("v1")
assert u != v
v = Quantity("v2", abbrev="ds")
assert u != v
v = Quantity("v3", abbrev="dm")
assert u != v
def test_add_sub():
u = Quantity("u")
v = Quantity("v")
w = Quantity("w")
u.set_global_relative_scale_factor(S(10), meter)
v.set_global_relative_scale_factor(S(5), meter)
w.set_global_relative_scale_factor(S(2), second)
assert isinstance(u + v, Add)
assert (u + v.convert_to(u)) == (1 + S.Half)*u
# TODO: eventually add this:
# assert (u + v).convert_to(u) == (1 + S.Half)*u
assert isinstance(u - v, Add)
assert (u - v.convert_to(u)) == S.Half*u
# TODO: eventually add this:
# assert (u - v).convert_to(u) == S.Half*u
def test_quantity_abs():
v_w1 = Quantity('v_w1')
v_w2 = Quantity('v_w2')
v_w3 = Quantity('v_w3')
v_w1.set_global_relative_scale_factor(1, meter/second)
v_w2.set_global_relative_scale_factor(1, meter/second)
v_w3.set_global_relative_scale_factor(1, meter/second)
expr = v_w3 - Abs(v_w1 - v_w2)
assert SI.get_dimensional_expr(v_w1) == (length/time).name
Dq = Dimension(SI.get_dimensional_expr(expr))
assert SI.get_dimension_system().get_dimensional_dependencies(Dq) == {
length: 1,
time: -1,
}
assert meter == sqrt(meter**2)
def test_check_unit_consistency():
u = Quantity("u")
v = Quantity("v")
w = Quantity("w")
u.set_global_relative_scale_factor(S(10), meter)
v.set_global_relative_scale_factor(S(5), meter)
w.set_global_relative_scale_factor(S(2), second)
def check_unit_consistency(expr):
SI._collect_factor_and_dimension(expr)
raises(ValueError, lambda: check_unit_consistency(u + w))
raises(ValueError, lambda: check_unit_consistency(u - w))
raises(ValueError, lambda: check_unit_consistency(u + 1))
raises(ValueError, lambda: check_unit_consistency(u - 1))
raises(ValueError, lambda: check_unit_consistency(1 - exp(u / w)))
def test_mul_div():
u = Quantity("u")
v = Quantity("v")
t = Quantity("t")
ut = Quantity("ut")
v2 = Quantity("v")
u.set_global_relative_scale_factor(S(10), meter)
v.set_global_relative_scale_factor(S(5), meter)
t.set_global_relative_scale_factor(S(2), second)
ut.set_global_relative_scale_factor(S(20), meter*second)
v2.set_global_relative_scale_factor(S(5), meter/second)
assert 1 / u == u**(-1)
assert u / 1 == u
v1 = u / t
v2 = v
# Pow only supports structural equality:
assert v1 != v2
assert v1 == v2.convert_to(v1)
# TODO: decide whether to allow such expression in the future
# (requires somehow manipulating the core).
# assert u / Quantity('l2', dimension=length, scale_factor=2) == 5
assert u * 1 == u
ut1 = u * t
ut2 = ut
# Mul only supports structural equality:
assert ut1 != ut2
assert ut1 == ut2.convert_to(ut1)
# Mul only supports structural equality:
lp1 = Quantity("lp1")
lp1.set_global_relative_scale_factor(S(2), 1/meter)
assert u * lp1 != 20
assert u**0 == 1
assert u**1 == u
# TODO: Pow only support structural equality:
u2 = Quantity("u2")
u3 = Quantity("u3")
u2.set_global_relative_scale_factor(S(100), meter**2)
u3.set_global_relative_scale_factor(Rational(1, 10), 1/meter)
assert u ** 2 != u2
assert u ** -1 != u3
assert u ** 2 == u2.convert_to(u)
assert u ** -1 == u3.convert_to(u)
def test_units():
assert convert_to((5*m/s * day) / km, 1) == 432
assert convert_to(foot / meter, meter) == Rational(3048, 10000)
# amu is a pure mass so mass/mass gives a number, not an amount (mol)
# TODO: need better simplification routine:
assert str(convert_to(grams/amu, grams).n(2)) == '6.0e+23'
# Light from the sun needs about 8.3 minutes to reach earth
t = (1*au / speed_of_light) / minute
# TODO: need a better way to simplify expressions containing units:
t = convert_to(convert_to(t, meter / minute), meter)
assert t.simplify() == Rational(49865956897, 5995849160)
# TODO: fix this, it should give `m` without `Abs`
assert sqrt(m**2) == m
assert (sqrt(m))**2 == m
t = Symbol('t')
assert integrate(t*m/s, (t, 1*s, 5*s)) == 12*m*s
assert (t * m/s).integrate((t, 1*s, 5*s)) == 12*m*s
def test_issue_quart():
assert convert_to(4 * quart / inch ** 3, meter) == 231
assert convert_to(4 * quart / inch ** 3, millimeter) == 231
def test_electron_rest_mass():
assert convert_to(electron_rest_mass, kilogram) == 9.1093837015e-31*kilogram
assert convert_to(electron_rest_mass, grams) == 9.1093837015e-28*grams
def test_issue_5565():
assert (m < s).is_Relational
def test_find_unit():
assert find_unit('coulomb') == ['coulomb', 'coulombs', 'coulomb_constant']
assert find_unit(coulomb) == ['C', 'coulomb', 'coulombs', 'planck_charge', 'elementary_charge']
assert find_unit(charge) == ['C', 'coulomb', 'coulombs', 'planck_charge', 'elementary_charge']
assert find_unit(inch) == [
'm', 'au', 'cm', 'dm', 'ft', 'km', 'ly', 'mi', 'mm', 'nm', 'pm', 'um', 'yd',
'nmi', 'feet', 'foot', 'inch', 'mile', 'yard', 'meter', 'miles', 'yards',
'inches', 'meters', 'micron', 'microns', 'angstrom', 'angstroms', 'decimeter',
'kilometer', 'lightyear', 'nanometer', 'picometer', 'centimeter', 'decimeters',
'kilometers', 'lightyears', 'micrometer', 'millimeter', 'nanometers', 'picometers',
'centimeters', 'micrometers', 'millimeters', 'nautical_mile', 'planck_length',
'nautical_miles', 'astronomical_unit', 'astronomical_units']
assert find_unit(inch**-1) == ['D', 'dioptre', 'optical_power']
assert find_unit(length**-1) == ['D', 'dioptre', 'optical_power']
assert find_unit(inch ** 2) == ['ha', 'hectare', 'planck_area']
assert find_unit(inch ** 3) == [
'L', 'l', 'cL', 'cl', 'dL', 'dl', 'mL', 'ml', 'liter', 'quart', 'liters', 'quarts',
'deciliter', 'centiliter', 'deciliters', 'milliliter',
'centiliters', 'milliliters', 'planck_volume']
assert find_unit('voltage') == ['V', 'v', 'volt', 'volts', 'planck_voltage']
assert find_unit(grams) == ['g', 't', 'Da', 'kg', 'me', 'mg', 'ug', 'amu', 'mmu', 'amus',
'gram', 'mmus', 'grams', 'pound', 'tonne', 'dalton', 'pounds',
'kilogram', 'kilograms', 'microgram', 'milligram', 'metric_ton',
'micrograms', 'milligrams', 'planck_mass', 'milli_mass_unit', 'atomic_mass_unit',
'electron_rest_mass', 'atomic_mass_constant']
def test_Quantity_derivative():
x = symbols("x")
assert diff(x*meter, x) == meter
assert diff(x**3*meter**2, x) == 3*x**2*meter**2
assert diff(meter, meter) == 1
assert diff(meter**2, meter) == 2*meter
def test_quantity_postprocessing():
q1 = Quantity('q1')
q2 = Quantity('q2')
SI.set_quantity_dimension(q1, length*pressure**2*temperature/time)
SI.set_quantity_dimension(q2, energy*pressure*temperature/(length**2*time))
assert q1 + q2
q = q1 + q2
Dq = Dimension(SI.get_dimensional_expr(q))
assert SI.get_dimension_system().get_dimensional_dependencies(Dq) == {
length: -1,
mass: 2,
temperature: 1,
time: -5,
}
def test_factor_and_dimension():
assert (3000, Dimension(1)) == SI._collect_factor_and_dimension(3000)
assert (1001, length) == SI._collect_factor_and_dimension(meter + km)
assert (2, length/time) == SI._collect_factor_and_dimension(
meter/second + 36*km/(10*hour))
x, y = symbols('x y')
assert (x + y/100, length) == SI._collect_factor_and_dimension(
x*m + y*centimeter)
cH = Quantity('cH')
SI.set_quantity_dimension(cH, amount_of_substance/volume)
pH = -log(cH)
assert (1, volume/amount_of_substance) == SI._collect_factor_and_dimension(
exp(pH))
v_w1 = Quantity('v_w1')
v_w2 = Quantity('v_w2')
v_w1.set_global_relative_scale_factor(Rational(3, 2), meter/second)
v_w2.set_global_relative_scale_factor(2, meter/second)
expr = Abs(v_w1/2 - v_w2)
assert (Rational(5, 4), length/time) == \
SI._collect_factor_and_dimension(expr)
expr = Rational(5, 2)*second/meter*v_w1 - 3000
assert (-(2996 + Rational(1, 4)), Dimension(1)) == \
SI._collect_factor_and_dimension(expr)
expr = v_w1**(v_w2/v_w1)
assert ((Rational(3, 2))**Rational(4, 3), (length/time)**Rational(4, 3)) == \
SI._collect_factor_and_dimension(expr)
def test_dimensional_expr_of_derivative():
l = Quantity('l')
t = Quantity('t')
t1 = Quantity('t1')
l.set_global_relative_scale_factor(36, km)
t.set_global_relative_scale_factor(1, hour)
t1.set_global_relative_scale_factor(1, second)
x = Symbol('x')
y = Symbol('y')
f = Function('f')
dfdx = f(x, y).diff(x, y)
dl_dt = dfdx.subs({f(x, y): l, x: t, y: t1})
assert SI.get_dimensional_expr(dl_dt) ==\
SI.get_dimensional_expr(l / t / t1) ==\
Symbol("length")/Symbol("time")**2
assert SI._collect_factor_and_dimension(dl_dt) ==\
SI._collect_factor_and_dimension(l / t / t1) ==\
(10, length/time**2)
def test_get_dimensional_expr_with_function():
v_w1 = Quantity('v_w1')
v_w2 = Quantity('v_w2')
v_w1.set_global_relative_scale_factor(1, meter/second)
v_w2.set_global_relative_scale_factor(1, meter/second)
assert SI.get_dimensional_expr(sin(v_w1)) == \
sin(SI.get_dimensional_expr(v_w1))
assert SI.get_dimensional_expr(sin(v_w1/v_w2)) == 1
def test_binary_information():
assert convert_to(kibibyte, byte) == 1024*byte
assert convert_to(mebibyte, byte) == 1024**2*byte
assert convert_to(gibibyte, byte) == 1024**3*byte
assert convert_to(tebibyte, byte) == 1024**4*byte
assert convert_to(pebibyte, byte) == 1024**5*byte
assert convert_to(exbibyte, byte) == 1024**6*byte
assert kibibyte.convert_to(bit) == 8*1024*bit
assert byte.convert_to(bit) == 8*bit
a = 10*kibibyte*hour
assert convert_to(a, byte) == 10240*byte*hour
assert convert_to(a, minute) == 600*kibibyte*minute
assert convert_to(a, [byte, minute]) == 614400*byte*minute
def test_conversion_with_2_nonstandard_dimensions():
good_grade = Quantity("good_grade")
kilo_good_grade = Quantity("kilo_good_grade")
centi_good_grade = Quantity("centi_good_grade")
kilo_good_grade.set_global_relative_scale_factor(1000, good_grade)
centi_good_grade.set_global_relative_scale_factor(S.One/10**5, kilo_good_grade)
charity_points = Quantity("charity_points")
milli_charity_points = Quantity("milli_charity_points")
missions = Quantity("missions")
milli_charity_points.set_global_relative_scale_factor(S.One/1000, charity_points)
missions.set_global_relative_scale_factor(251, charity_points)
assert convert_to(
kilo_good_grade*milli_charity_points*millimeter,
[centi_good_grade, missions, centimeter]
) == S.One * 10**5 / (251*1000) / 10 * centi_good_grade*missions*centimeter
def test_eval_subs():
energy, mass, force = symbols('energy mass force')
expr1 = energy/mass
units = {energy: kilogram*meter**2/second**2, mass: kilogram}
assert expr1.subs(units) == meter**2/second**2
expr2 = force/mass
units = {force:gravitational_constant*kilogram**2/meter**2, mass:kilogram}
assert expr2.subs(units) == gravitational_constant*kilogram/meter**2
def test_issue_14932():
assert (log(inch) - log(2)).simplify() == log(inch/2)
assert (log(inch) - log(foot)).simplify() == -log(12)
p = symbols('p', positive=True)
assert (log(inch) - log(p)).simplify() == log(inch/p)
def test_issue_14547():
# the root issue is that an argument with dimensions should
# not raise an error when the `arg - 1` calculation is
# performed in the assumptions system
from sympy.physics.units import foot, inch
from sympy.core.relational import Eq
assert log(foot).is_zero is None
assert log(foot).is_positive is None
assert log(foot).is_nonnegative is None
assert log(foot).is_negative is None
assert log(foot).is_algebraic is None
assert log(foot).is_rational is None
# doesn't raise error
assert Eq(log(foot), log(inch)) is not None # might be False or unevaluated
x = Symbol('x')
e = foot + x
assert e.is_Add and set(e.args) == {foot, x}
e = foot + 1
assert e.is_Add and set(e.args) == {foot, 1}
def test_issue_22164():
warnings.simplefilter("error")
dm = Quantity("dm")
SI.set_quantity_dimension(dm, length)
SI.set_quantity_scale_factor(dm, 1)
bad_exp = Quantity("bad_exp")
SI.set_quantity_dimension(bad_exp, length)
SI.set_quantity_scale_factor(bad_exp, 1)
expr = dm ** bad_exp
# deprecation warning is not expected here
SI._collect_factor_and_dimension(expr)
def test_issue_22819():
from sympy.physics.units import tonne, gram, Da
from sympy.physics.units.systems.si import dimsys_SI
assert tonne.convert_to(gram) == 1000000*gram
assert dimsys_SI.get_dimensional_dependencies(area) == {length: 2}
assert Da.scale_factor == 1.66053906660000e-24
def test_issue_20288():
from sympy.core.numbers import E
from sympy.physics.units import energy
u = Quantity('u')
v = Quantity('v')
SI.set_quantity_dimension(u, energy)
SI.set_quantity_dimension(v, energy)
u.set_global_relative_scale_factor(1, joule)
v.set_global_relative_scale_factor(1, joule)
expr = 1 + exp(u**2/v**2)
assert SI._collect_factor_and_dimension(expr) == (1 + E, Dimension(1))
def test_issue_24062():
from sympy.core.numbers import E
from sympy.physics.units import impedance, capacitance, time, ohm, farad, second
R = Quantity('R')
C = Quantity('C')
T = Quantity('T')
SI.set_quantity_dimension(R, impedance)
SI.set_quantity_dimension(C, capacitance)
SI.set_quantity_dimension(T, time)
R.set_global_relative_scale_factor(1, ohm)
C.set_global_relative_scale_factor(1, farad)
T.set_global_relative_scale_factor(1, second)
expr = T / (R * C)
dim = SI._collect_factor_and_dimension(expr)[1]
assert SI.get_dimension_system().is_dimensionless(dim)
exp_expr = 1 + exp(expr)
assert SI._collect_factor_and_dimension(exp_expr) == (1 + E, Dimension(1))
def test_issue_24211():
from sympy.physics.units import time, velocity, acceleration, second, meter
V1 = Quantity('V1')
SI.set_quantity_dimension(V1, velocity)
SI.set_quantity_scale_factor(V1, 1 * meter / second)
A1 = Quantity('A1')
SI.set_quantity_dimension(A1, acceleration)
SI.set_quantity_scale_factor(A1, 1 * meter / second**2)
T1 = Quantity('T1')
SI.set_quantity_dimension(T1, time)
SI.set_quantity_scale_factor(T1, 1 * second)
expr = A1*T1 + V1
# should not throw ValueError here
SI._collect_factor_and_dimension(expr)
def test_prefixed_property():
assert not meter.is_prefixed
assert not joule.is_prefixed
assert not day.is_prefixed
assert not second.is_prefixed
assert not volt.is_prefixed
assert not ohm.is_prefixed
assert centimeter.is_prefixed
assert kilometer.is_prefixed
assert kilogram.is_prefixed
assert pebibyte.is_prefixed
def test_physics_constant():
from sympy.physics.units import definitions
for name in dir(definitions):
quantity = getattr(definitions, name)
if not isinstance(quantity, Quantity):
continue
if name.endswith('_constant'):
assert isinstance(quantity, PhysicalConstant), f"{quantity} must be PhysicalConstant, but is {type(quantity)}"
assert quantity.is_physical_constant, f"{name} is not marked as physics constant when it should be"
for const in [gravitational_constant, molar_gas_constant, vacuum_permittivity, speed_of_light, elementary_charge]:
assert isinstance(const, PhysicalConstant), f"{const} must be PhysicalConstant, but is {type(const)}"
assert const.is_physical_constant, f"{const} is not marked as physics constant when it should be"
assert not meter.is_physical_constant
assert not joule.is_physical_constant