Example python function to get the 'inverse longitude' from opposite global hemisphere, from -180 to 180.

wraparound_lon.py

"""
Example python and numpy function to get the 'inverse longitude' from opposite global hemisphere, from -180 to 180.
"""
import numpy as np


def wraparound_lon(x):
    """Get the 'inverse longitude' from opposite global hemisphere, from -180 to 180.
    
    I'm not sure what the proper term for this is.
    """
    a = x - 180.0
    b = 360.0
    # Plug into nearest modulo int:
    return a - b * np.round(a / b)  # Can also just use `round` if numpy not needed.

  
# For eg, these should pass.
assert wraparound_lon(-130) == 50.0
assert wraparound_lon(50) == -130.0
assert wraparound_lon(130) == -50.0
assert wraparound_lon(-50) == 130.0
assert wraparound_lon(10) == -170.0
assert wraparound_lon(0.5) == -179.5