compass_robot.py 文件源码

def statisticalNoiseReduction(values, std_factor_threshold = 2):
    """
    Eliminates outlier values that go beyond a certain threshold.

    :param values: The list of elements that are being filtered.
    :param std_factor_threshold: Filtering aggressiveness. The bigger the value, the more it filters.
    :return: The filtered list.

    """

    if len(values) == 0:
        return []

    valarray = np.array(values)
    mean = valarray.mean()
    standard_deviation = valarray.std()
    # just return if we only got constant values
    if standard_deviation == 0:
        return values

    # remove outlier values
    valarray = valarray[(valarray > mean - std_factor_threshold * standard_deviation)
                        & (valarray < mean + std_factor_threshold * standard_deviation)]

    return list(valarray)