| 摘要 |
The invention provides methods and apparatus, including computer program products, for correcting outlier values in a series of values over time, the values representing a predetermined numerical parameter, the method comprising the following steps: for a predetermined time interval of the time series, the time interval having a beginning point and an end point, calculating an ex-post forecast time series on the basis of the historical time series and a predetermined model function; defining a lower tolerance limit line and an upper tolerance limit line on the basis of the ex-post forecast time series and on a quality function over the time interval; beginning at the beginning point of the time interval, correcting the historical time series by replacing the first value of the historical time series outside of the tolerance lines by a predetermined value not outside the tolerance lines; recalculating the ex-post forecast time series on the basis of the corrected historical time series (s_h) and the predetermined model function; and redefining the tolerance lines on the basis of the recalculated ex-post forecast time series (s_ep) and the quality function, whereby the quality function (qf) takes only values into account until the time point where the last outlier value has been replaced; repeating the above steps until all outlier values of the historical time series have been replaced.
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