def step_function(x: float, step_coordinate: float = 0, value_1: float = 0, value_2: float = 1) -> float:
    """Simple step function.

    Parameters
    ----------
    x : float
        Coordinate.
    step_coordinate: float
        Step coordiante.
    value_1 : float
        Function returns value_1 if x < step_coordinate.
    value_2 : float
        Function returns value_2 if x >= step_coordinate.

    Returns
    -------
    float

    """
    return value_1 if x < step_coordinate else value_2