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SAP HANA Predictive Analysis Library (PAL)

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Expected Result<br />

<strong>PAL</strong>_NEW_SCALING_TBL:<br />

Related Information<br />

Scaling Range [page 479]<br />

3.6.7 Principal Component <strong>Analysis</strong> (PCA)<br />

Principal component analysis (PCA) aims at reducing the dimensionality of multivariate data while accounting<br />

for as much of the variation in the original data set as possible. This technique is especially useful when the<br />

variables within the data set are highly correlated.<br />

Principal components seek to transform the original variables to a new set of variables that are:<br />

●<br />

●<br />

●<br />

linear combinations of the variables in the data set;<br />

uncorrelated with each other;<br />

ordered according to the amount of variations of the original variables that they explain.<br />

The signs of the columns of the loadings matrix are arbitrary, and may differ between different<br />

implementations for PCA.<br />

Note that if there exists one variable which has constant value across data items, you cannot scale variables<br />

any more.<br />

Prerequisites<br />

●<br />

●<br />

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

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

PCA<br />

This is a principal component analysis function.<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 457

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