25.10.2016 Views

SAP HANA Predictive Analysis Library (PAL)

sap_hana_predictive_analysis_library_pal_en

sap_hana_predictive_analysis_library_pal_en

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

<strong>PAL</strong>_FPGROWTH_VALUES_TBL:<br />

3.4.3 K-Optimal Rule Discovery (KORD)<br />

K-optimal rule discovery (KORD) follows the idea of generating association rules with respect to a well-defined<br />

measure, instead of first finding all frequent itemsets and then generating all possible rules. The algorithm only<br />

calculates the top-k rules according to that measure. The size of the right hand side (RHS) of those rules is<br />

restricted to one. Futhermore, the KORD implementation generates only non-redundant rules.<br />

The algorithm's search strategy is based on the so-called OPUS search. While the search space of all possible<br />

LHSs is traversed in a depth-first manner, the information about all qualified RHSs of the rules for a given LHS<br />

is propagated further to the deeper search levels. KORD does not build a real tree search structure; instead it<br />

traverses the LHSs in a specific order, which allows the pruning of the search space by simply not visiting<br />

those itemsets subsequently. In this way it is possible to use pruning rules which restrict the possible LHSs<br />

and RHSs at different rule generation stages.<br />

Prerequisites<br />

●<br />

●<br />

There are no duplicated items in each transaction.<br />

The input data does not contain null value. The algorithm will issue errors when encountering null values.<br />

KORD<br />

Procedure Generation<br />

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

'', );<br />

The signature table should contain the following records:<br />

Table 240:<br />

Position Schema Name Table Type Name Parameter Type<br />

1 <br />

IN<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 315

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!