clouddrift.sphere.bearing#
- clouddrift.sphere.bearing(lon1: float | list | ndarray | DataArray, lat1: float | list | ndarray | DataArray, lon2: float | list | ndarray | DataArray, lat2: float | list | ndarray | DataArray) float | ndarray[source]#
Return elementwise initial (forward) bearing in radians from arrays of latitude and longitude in degrees, based on the spherical law of cosines.
The formula is:
θ = atan2(cos φ1 ⋅ sin φ2 - sin φ1 ⋅ cos φ2 ⋅ cos Δλ, sin Δλ ⋅ cos φ2)
where (φ, λ) is (lat, lon) and θ is bearing, all in radians. Bearing is defined as zero toward East and positive counterclockwise.
Parameters#
- lon1float or array-like
Longitudes of the first set of points, in degrees
- lat1float or array-like
Latitudes of the first set of points, in degrees
- lon2float or array-like
Longitudes of the second set of points, in degrees
- lat2float or array-like
Latitudes of the second set of points, in degrees
Returns#
- thetafloat or np.ndarray
Bearing angles in radians
Examples#
Calculate the bearing of one degree longitude on the equator:
>>> bearing(0, 0, 1, 0) 0.0
Calculate the bearing of 10 degrees longitude at 45-degrees North latitude:
>>> bearing(0, 45, 10, 45) 0.06178508761798218