els so
that the fraction of positive ones is equal to the specified
value. This computes the normalised PR curves of [2]
</p></dd><dt>
About the PR curve
</dt><dd><p>
This section uses the same symbols used in the documentation of
the <a href="vl_roc.html">VL_ROC</a>() function. In addition to those quantities, define:
</p><pre>
  PRECISION(S) = TP(S) / (TP(S) + FP(S))
  RECALL(S) = TPR(S) = TP(S) / P
</pre><p>
The precision is the fraction of positivie predictions which are
correct, and the recall is the f