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SAP HANA Predictive Analysis Library (PAL)

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Assume we have m observation pairs (x i ,y i ). Then we obtain an overdetermined linear system<br />

=Y,<br />

with is m×(n+1) matrix, is (n+1)×1 matrix, and Y is m×1 matrix, where m>n+1. Since equality is<br />

usually not exactly satisfiable, when m > n+1, the least squares solution<br />

minimizes the squared Euclidean<br />

norm of the residual vector r(<br />

) so that<br />

Elastic net regularization for multiple linear regression seeks to find<br />

that minimizes:<br />

Where .<br />

Here<br />

and λ≥0. If α=0, we have the ridge regularization; if α=1, we have the LASSO regularization.<br />

The implementation also supports calculating F and R^2 to determine statistical significance.<br />

Prerequisites<br />

●<br />

●<br />

●<br />

No missing or null data in the inputs.<br />

The data is numeric, not categorical.<br />

Given n independent variables, there must be at least n+1 records available for analysis.<br />

LRREGRESSION<br />

This is a multiple linear regression function.<br />

Procedure Generation<br />

CALL SYS.AFLLANG_WRAPPER_PROCEDURE_CREATE (‘AFL<strong>PAL</strong>’, ‘LRREGRESSION’,<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 265

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