m2m模型翻译
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"""
MKS unit system.
MKS stands for "meter, kilogram, second, ampere".
"""
from typing import List
from sympy.physics.units.definitions import Z0, A, C, F, H, S, T, V, Wb, ohm
from sympy.physics.units.definitions.dimension_definitions import (
capacitance, charge, conductance, current, impedance, inductance,
magnetic_density, magnetic_flux, voltage)
from sympy.physics.units.prefixes import PREFIXES, prefix_unit
from sympy.physics.units.systems.mks import MKS, dimsys_length_weight_time
from sympy.physics.units.quantities import Quantity
dims = (voltage, impedance, conductance, current, capacitance, inductance, charge,
magnetic_density, magnetic_flux)
units = [A, V, ohm, S, F, H, C, T, Wb]
all_units = [] # type: List[Quantity]
for u in units:
all_units.extend(prefix_unit(u, PREFIXES))
all_units.append(Z0)
dimsys_MKSA = dimsys_length_weight_time.extend([
# Dimensional dependencies for base dimensions (MKSA not in MKS)
current,
], new_dim_deps=dict(
# Dimensional dependencies for derived dimensions
voltage=dict(mass=1, length=2, current=-1, time=-3),
impedance=dict(mass=1, length=2, current=-2, time=-3),
conductance=dict(mass=-1, length=-2, current=2, time=3),
capacitance=dict(mass=-1, length=-2, current=2, time=4),
inductance=dict(mass=1, length=2, current=-2, time=-2),
charge=dict(current=1, time=1),
magnetic_density=dict(mass=1, current=-1, time=-2),
magnetic_flux=dict(length=2, mass=1, current=-1, time=-2),
))
MKSA = MKS.extend(base=(A,), units=all_units, name='MKSA', dimension_system=dimsys_MKSA)