def find_change_in_general_direction(curvature):
    """
    return indecies of where the singn of curvature has flipped
    """
    curv_pos = curvature > 0
    split = []
    currently_pos = curv_pos[0]
    for c, is_pos in zip(range(curvature.shape[0]),curv_pos):
        if is_pos !=currently_pos:
            currently_pos = is_pos
            split.append(c)
    return split