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SAP HANA Predictive Analysis Library (PAL)

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Related Information<br />

<strong>SAP</strong> <strong>HANA</strong> Smart Data Streaming: Developer Guide<br />

3.2 Classification Algorithms<br />

This section describes the classification algorithms that are provided by the <strong>Predictive</strong> <strong>Analysis</strong> <strong>Library</strong>.<br />

3.2.1 Area Under Curve (AUC)<br />

Area under curve (AUC) is a traditional method to evaluate the performance of classification algorithms.<br />

Basically, it can evaluate the binary classifier, but can be extended to multiple-class condition easily.<br />

In an area under curve algorithm, curve is the receiver operating characteristic (ROC) curve. The curve can be<br />

obtained by plotting the true positive rate (TPR) against the false positive rate (FPR) at several threshold. The<br />

calculation formulas are listed below.<br />

Where:<br />

TP: true positive<br />

FN: false negative<br />

FP: false positive<br />

TN: true negative<br />

After plotting the ROC curve, you can calculate the area under the curve by using numerical integral<br />

algorithms such as Simpson’s rule. The value of AUC ranges from 0.5 to 1. If the AUC equals to 1, the classifier<br />

is expected to have perfect performance.<br />

Prerequisite<br />

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

118 P U B L I C<br />

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

<strong>PAL</strong> Functions

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