r the precision-recall curve. If the INTERPOLATE
option is set to FALSE, then trapezoidal interpolation is used
to integrate the PR curve. If the INTERPOLATE option is set to
TRUE, then the curve is piecewise constant and no other
approximation is introduced in the calculation of the area. In
the latter case, INFO.AUC is the same as INFO.AP.
</p></dd><dt>
info.ap
</dt><dd><p>
Average precision as defined by TREC. This is the average of the
precision observed each time a new positive sample is
recalled. In t