def calculate_centroid(gps_bounds):
    """Given a set of GPS boundaries, return lat/lon of centroid.

    gps_bounds -- (lat(y) min, lat(y) max, long(x) min, long(x) max)

    Returns:
        Tuple of (lat, lon) representing centroid
    """

    return (
        gps_bounds[0] + float(gps_bounds[1] - gps_bounds[0])/2,
        gps_bounds[2] + float(gps_bounds[3] - gps_bounds[2])/2,
    )