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SAP HANA Predictive Analysis Library (PAL)

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Once the trend and seasonality are determined, you can eventually obtain the de-trended and de-seasonalized<br />

series, that is, the random. As illustrated before, the trend component is estimated as moving average<br />

seasonal component, correspondingly, can be estimated as<br />

. The<br />

decomposition,<br />

, additive<br />

or,<br />

decomposition.<br />

, multiplicative<br />

Consequently, the random component can be calculated straightforwardly.<br />

Note that during the course of calculating the moving average, the element at t is determined by x(t<br />

−q, ..., t+q), where d=2q or d=2q+1, d is the seasonality cycle. As a result, the trend and random series<br />

are valid only within the time range between q and n−q. Should there be no seasonality, the random series is<br />

just exactly the input time series.<br />

Prerequisites<br />

● No null data in the inputs. The time periods should be unique and equal sampling.<br />

● The length of time series must be at least 1.<br />

● The data type of time periods is integer. The data type of time series is integer or double.<br />

SEASONALITYTEST<br />

This function identifies the seasonality and calculates de-seasonalized series (random) of a time series.<br />

Procedure Generation<br />

CALL SYS.AFLLANG_WRAPPER_PROCEDURE_CREATE (‘AFL<strong>PAL</strong>’, ‘SEASONALITYTEST’,<br />

‘’, '', );<br />

<strong>SAP</strong> <strong>HANA</strong> <strong>Predictive</strong> <strong>Analysis</strong> <strong>Library</strong> (<strong>PAL</strong>)<br />

<strong>PAL</strong> Functions P U B L I C 417

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