def test_error_definition():
raises(ValueError,
lambda: DimensionSystem((Dimension(time=1, name="time", symbol="T"),
Dimension(length=1, symbol="L"),
Dimension(mass=1, name="mass"),
Dimension(current=1))))
raises(ValueError, lambda: DimensionSystem((length, time, velocity)))
def test_add_sub():
length = Dimension(length=1)
assert length.add(length) == length
assert length.sub(length) == length
assert -length == length
raises(TypeError, lambda: length.add(1))
raises(TypeError, lambda: length.sub(1))
raises(ValueError, lambda: length.add(Dimension(time=1)))
raises(ValueError, lambda: length.sub(Dimension(time=1)))
def test_str_repr():
assert str(DimensionSystem((length, time), name="MS")) == "MS"
dimsys = DimensionSystem((Dimension(length=1, symbol="L"),
Dimension(time=1, symbol="T")))
assert str(dimsys) == "(L, T)"
dimsys = DimensionSystem((Dimension(length=1, name="length", symbol="L"),
Dimension(time=1, name="time")))
assert str(dimsys) == "(L, time)"
assert (repr(DimensionSystem((length, time), name="MS"))
== "<DimensionSystem: ({'length': 1}, {'time': 1})>")
def test_error_definition():
# tuple with more or less than two entries
raises(ValueError, lambda: Dimension(("length", 1, 2)))
raises(ValueError, lambda: Dimension(["length"]))
# non-number power
raises(TypeError, lambda: Dimension(length="a"))
# non-dict/list/tuple as positional arg
raises(TypeError, lambda: Dimension("length"))
# non-number with named argument
raises(TypeError, lambda: Dimension(length=(1, 2)))
def test_dict_properties():
dic = {"length": sympify(1), "time": sympify(2)}
d = Dimension(dic)
assert d["length"] == 1
assert set(d.items()) == set(dic.items())
assert len(d) == 2
assert d.get("length") == 1
assert d.get("mass") is None
assert ("length" in d) is True
assert ("mass" in d) is False
def test_definition():
base = (length, time)
ms = DimensionSystem(base, (velocity,), "MS", "MS system")
assert ms._base_dims == DimensionSystem.sort_dims(base)
assert set(ms._dims) == set(base + (velocity,))
assert ms.name == "MS"
assert ms.descr == "MS system"
assert ms._can_transf_matrix is None
# be sure that there is no duplicates in ms._dims
dims = (Dimension(length=1), Dimension(length=1, symbol="l"))
ms = DimensionSystem(base, dims)
assert set(ms._dims) == set(base)
def test_get_dim():
ms = DimensionSystem((length, time), (velocity,))
assert ms.get_dim("L") == length
assert ms.get_dim("length") == length
assert ms.get_dim(length) == length
assert ms.get_dim(Dimension(length=1)) == length
assert ms["L"] == ms.get_dim("L")
raises(KeyError, lambda: ms["M"])
def test_definition():
length = Dimension(name="length", symbol="L", length=1)
assert length.get('length') == 1
assert length.get('time') is None
assert length.name == "length"
assert length.symbol == "L"
halflength = Dimension(name="length", length=0.5)
assert halflength.get('length') == sympify("1/2")
def test_properties():
assert Dimension(length=1).is_dimensionless is False
assert Dimension().is_dimensionless is True
assert Dimension(length=0).is_dimensionless is True
assert Dimension(length=1).has_integer_powers is True
assert Dimension(length=-1).has_integer_powers is True
assert Dimension(length=1.5).has_integer_powers is False
def test_mul_div_exp():
length = Dimension(length=1)
time = Dimension(time=1)
velocity = length.div(time)
assert length.pow(2) == Dimension(length=2)
assert length.mul(length) == length.pow(2)
assert length.mul(time) == Dimension(length=1, time=1)
assert velocity == Dimension(length=1, time=-1)
assert velocity.pow(2) == Dimension(length=2, time=-2)
raises(TypeError, lambda: length.pow("a"))
def test_str():
assert str(Dimension(length=1)) == "{'length': 1}"
assert str(Dimension(length=1, symbol="L")) == "L"
assert str(Dimension(length=1, name="length")) == "length"
assert str(Dimension(length=1, symbol="L", name="length")) == 'L'
"""
MKS unit system.
MKS stands for "meter, kilogram, second, ampere".
"""
from __future__ import division
from sympy import pi
from sympy.physics.unitsystems.dimensions import Dimension
from sympy.physics.unitsystems.units import Unit, Constant
from sympy.physics.unitsystems.prefixes import PREFIXES, prefix_unit
from sympy.physics.unitsystems.systems.mks import mks_dim, mks
# base dimensions
current = Dimension(name='current', symbol='I', current=1)
# derived dimensions
voltage = Dimension(name='voltage',
symbol='U',
mass=1,
length=2,
current=-1,
time=-3)
impedance = Dimension(name='impedance',
symbol='Z',
mass=1,
length=2,
current=-2,
time=-3)
conductance = Dimension(name='conductance',
""" Naturalunit system. The natural system comes from "setting c = 1, hbar = 1". From the computer point of view it means that we use velocity and action instead of length and time. Moreover instead of mass we use energy. """ from __future__ import division from sympy.physics.unitsystems.dimensions import Dimension, DimensionSystem from sympy.physics.unitsystems.units import Unit, Constant, UnitSystem from sympy.physics.unitsystems.prefixes import PREFIXES, prefix_unit # base dimensions 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)
def test_call():
current = Dimension(name="current", symbol="I", current=1)
mksa = DimensionSystem((length, time, mass, current), (action,))
assert mksa(action) == mksa.print_dim_base(action)
# -*- coding: utf-8 -*-
from sympy import Matrix, eye
from sympy.physics.unitsystems.dimensions import Dimension, DimensionSystem
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)
velocity = Dimension(name="velocity", symbol="V", length=1, time=-1)
action = Dimension(name="action", symbol="A", length=2, mass=1, time=-2)
def test_definition():
base = (length, time)
ms = DimensionSystem(base, (velocity,), "MS", "MS system")
assert ms._base_dims == DimensionSystem.sort_dims(base)
assert set(ms._dims) == set(base + (velocity,))
assert ms.name == "MS"
assert ms.descr == "MS system"
assert ms._can_transf_matrix is None
# be sure that there is no duplicates in ms._dims
dims = (Dimension(length=1), Dimension(length=1, symbol="l"))
ms = DimensionSystem(base, dims)
assert set(ms._dims) == set(base)