def __init__(self, time_series, baseline_time_series=None, smoothing_factor=None):
super(DerivativeDetector, self).__init__(self.__class__.__name__, time_series, baseline_time_series)<EOL>self.smoothing_factor = (smoothing_factor or DEFAULT_DERI_SMOOTHING_FACTOR)<EOL>self.time_series_items = self.time_series.items()<EOL>
Initializer
:param TimeSeries time_series: a TimeSeries object.
:param TimeSeries baseline_time_series: baseline TimeSeries.
:param float smoothing_factor: smoothing factor.