"""Module for the velocity class."""
# ruff: noqa: TID252
from typing import overload
from ..length import Unit as DistanceUnit
from ..length import get_unit_abbreviation as get_distance_unit_abbreviation
from ..length import (
get_unit_delta_per_metre as get_distance_unit_delta_per_metre,
)
from ..length import get_unit_name as get_distance_unit_name
from ..time import Unit as TimeUnit
from ..time import get_unit_abbreviation as get_time_unit_abbreviation
from ..time import get_unit_delta_per_second as get_time_unit_delta_per_second
from ..time import get_unit_name as get_time_unit_name
[docs]
class Velocity:
"""The rate of change of the displacement of an object wrt time."""
[docs]
def __init__(
self, value: float, distance_unit: DistanceUnit, time_unit: TimeUnit
) -> None:
"""Initialise a new velocity."""
self._value = value
self._distance_unit = distance_unit
self._time_unit = time_unit
[docs]
def as_unit(self, distance_unit: DistanceUnit, time_unit: TimeUnit) -> float:
"""Return the velocity in the specified units."""
internal_distance_unit_delta_per_metre = get_distance_unit_delta_per_metre(
self._distance_unit
)
internal_time_unit_delta_per_second = get_time_unit_delta_per_second(
self._time_unit
)
internal_unit_to_metre_per_second_factor = (
internal_time_unit_delta_per_second / internal_distance_unit_delta_per_metre
)
value_as_metre_per_second = (
internal_unit_to_metre_per_second_factor * self._value
)
external_distance_unit_delta_per_metre = get_distance_unit_delta_per_metre(
distance_unit
)
external_time_unit_delta_per_second = get_time_unit_delta_per_second(time_unit)
metre_per_second_to_external_unit_factor = (
external_distance_unit_delta_per_metre / external_time_unit_delta_per_second
)
return metre_per_second_to_external_unit_factor * value_as_metre_per_second
[docs]
def __mul__(self, value: float) -> "Velocity":
"""Return a velocity scaled by the value."""
scaled_value = self._value * value
return Velocity(scaled_value, self._distance_unit, self._time_unit)
[docs]
def __rmul__(self, value: float) -> "Velocity":
"""Return a velocity scaled by the value."""
return self * value
@overload
def __truediv__(self, other: float) -> "Velocity": ...
@overload
def __truediv__(self, other: "Velocity") -> float: ...
[docs]
def __truediv__(self, other: "float | Velocity") -> "Velocity | float":
"""Return a scaled velocity or the ratio between the velocities.
The behaviour depends upon the type of the argument.
- If the argument is a :py:class:`float`, return a velocity scaled by the
inverse of the value
- If the argument is a :py:class:`Velocity`, return the ratio between the two
velocities
"""
if isinstance(other, Velocity):
value_as_metre_per_second = self.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
other_value_as_metre_per_second = other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
return value_as_metre_per_second / other_value_as_metre_per_second
return (1 / other) * self
[docs]
def __add__(self, other: "Velocity") -> "Velocity":
"""Return the sum of two velocities."""
value_as_metre_per_second = self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND)
other_value_as_metre_per_second = other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
value_sum_as_metre_per_second = (
value_as_metre_per_second + other_value_as_metre_per_second
)
return Velocity(
value_sum_as_metre_per_second, DistanceUnit.METRE, TimeUnit.SECOND
)
[docs]
def __sub__(self, other: "Velocity") -> "Velocity":
"""Return the difference of two velocities."""
value_as_metre_per_second = self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND)
other_value_as_metre_per_second = other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
value_difference_as_metre_per_second = (
value_as_metre_per_second - other_value_as_metre_per_second
)
return Velocity(
value_difference_as_metre_per_second,
DistanceUnit.METRE,
TimeUnit.SECOND,
)
[docs]
def __neg__(self) -> "Velocity":
"""Return the inverse of the velocity."""
return -1 * self
[docs]
def __abs__(self) -> "Velocity":
"""Return the absolute version of the velocity."""
absolute_value = abs(self._value)
return Velocity(absolute_value, self._distance_unit, self._time_unit)
[docs]
def __floordiv__(self, other: "Velocity") -> float:
"""Return the floored ratio between the velocities."""
value_as_metre_per_second = self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND)
other_value_as_metre_per_second = other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
return value_as_metre_per_second // other_value_as_metre_per_second
[docs]
def __mod__(self, other: "Velocity") -> float:
"""Return the remainder of the ratio between the velocity."""
value_as_metre_per_second = self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND)
other_value_as_metre_per_second = other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
return value_as_metre_per_second % other_value_as_metre_per_second
[docs]
def __divmod__(self, other: "Velocity") -> tuple[float, float]:
"""Return the quotient & remainder of the ratio between the velocities."""
value_as_metre_per_second = self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND)
other_value_as_metre_per_second = other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
return divmod(value_as_metre_per_second, other_value_as_metre_per_second)
[docs]
def __eq__(self, other: object) -> bool:
"""Return whether the objects are equal velocities."""
if not isinstance(other, Velocity):
return NotImplemented
return self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND) == other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
[docs]
def __lt__(self, other: "Velocity") -> bool:
"""Return whether the velocity is less than the other."""
return self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND) < other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
[docs]
def __le__(self, other: "Velocity") -> bool:
"""Return whether the velocity is less than or equal to the other."""
return self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND) <= other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
[docs]
def __gt__(self, other: "Velocity") -> bool:
"""Return whether the velocity is greater than the other."""
return self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND) > other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
[docs]
def __ge__(self, other: "Velocity") -> bool:
"""Return whether the velocity is greater than or equal to the other."""
return self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND) >= other.as_unit(
DistanceUnit.METRE, TimeUnit.SECOND
)
[docs]
def __hash__(self) -> int:
"""Return the hash of the velocity."""
return hash(self.as_unit(DistanceUnit.METRE, TimeUnit.SECOND))
def __str__(self) -> str:
"""Return a string representation of the velocity."""
return (
f"{self._value} "
f"{get_distance_unit_abbreviation(self._distance_unit)}/"
f"{get_time_unit_abbreviation(self._time_unit)}"
)
def __repr__(self) -> str:
"""Return a string representation of the velocity for developers."""
return (
f"{__class__.__name__}({self._value},"
f" {get_distance_unit_name(self._distance_unit)},"
f" {get_time_unit_name(self._time_unit)})"
)