Boolean variable denoting if the variance of x is greater than its standard deviation. Is equal to variance of x
    being larger than 1

    :param x: the time series to calculate the feature of
    :type x: numpy.ndarray
    :return: the value of this feature
    :return type: bool

def variance_larger_than_standard_deviation(x):
    """
    Boolean variable denoting if the variance of x is greater than its standard deviation. Is equal to variance of x
    being larger than 1

    :param x: the time series to calculate the feature of
    :type x: numpy.ndarray
    :return: the value of this feature
    :return type: bool
    """
    y = np.var(x)
    return y > np.sqrt(y)