def test_angle_to_name():
expect(angle_to_name(0)) == 'North'
expect(angle_to_name(360)) == 'North'
expect(angle_to_name(45)) == 'North-east'
expect(angle_to_name(292)) == 'West'
expect(angle_to_name(293)) == 'North-west'
expect(angle_to_name(0, 4)) == 'North'
expect(angle_to_name(360, 16)) == 'North'
expect(angle_to_name(45, 4, True)) == 'NE'
expect(angle_to_name(292, 16, True)) == 'WNW'
def bearing(self, other, format='numeric'):
"""Calculate the initial bearing from self to other.
.. note::
Applying common plane Euclidean trigonometry to bearing calculations
suggests to us that the bearing between point A to point B is equal
to the inverse of the bearing from Point B to Point A, whereas
spherical trigonometry is much more fun. If the ``bearing`` method
doesn't make sense to you when calculating return bearings there are
plenty of resources on the web that explain spherical geometry.
.. todo:: Add Rhumb line calculation
:param Point other: Location to calculate bearing to
:param str format: Format of the bearing string to return
:rtype: ``float``
:return: Initial bearing from self to other in degrees
:raise ValueError: Unknown value for ``format``
"""
longitude_difference = other.rad_longitude - self.rad_longitude
y = math.sin(longitude_difference) * math.cos(other.rad_latitude)
x = math.cos(self.rad_latitude) * math.sin(other.rad_latitude) - \
math.sin(self.rad_latitude) * math.cos(other.rad_latitude) * \
math.cos(longitude_difference)
bearing = math.degrees(math.atan2(y, x))
# Always return positive North-aligned bearing
bearing = (bearing + 360) % 360
if format == 'numeric':
return bearing
elif format == 'string':
return utils.angle_to_name(bearing)
else:
raise ValueError('Unknown format type %r' % format)
def final_bearing(self, other, format='numeric'):
"""Calculate the final bearing from self to other.
.. seealso::
:meth:`bearing`
:param Point other: Location to calculate final bearing to
:param str format: Format of the bearing string to return
:rtype: ``float``
:return: Final bearing from self to other in degrees
:raise ValueError: Unknown value for ``format``
"""
final_bearing = (other.bearing(self) + 180) % 360
if format == 'numeric':
return final_bearing
elif format == 'string':
return utils.angle_to_name(final_bearing)
else:
raise ValueError('Unknown format type %r' % format)
def test_angle_to_name(args, result):
assert angle_to_name(*args) == result
