double RangeSearchRules<MetricType, TreeType>::Score(const size_t queryIndex,
TreeType& referenceNode)
{
// We must get the minimum and maximum distances and store them in this
// object.
math::Range distances;
if (tree::TreeTraits<TreeType>::FirstPointIsCentroid)
{
// In this situation, we calculate the base case. So we should check to be
// sure we haven't already done that.
double baseCase;
if (tree::TreeTraits<TreeType>::HasSelfChildren &&
(referenceNode.Parent() != NULL) &&
(referenceNode.Point(0) == referenceNode.Parent()->Point(0)))
{
// If the tree has self-children and this is a self-child, the base case
// was already calculated.
baseCase = referenceNode.Parent()->Stat().LastDistance();
lastQueryIndex = queryIndex;
lastReferenceIndex = referenceNode.Point(0);
}
else
{
// We must calculate the base case by hand.
baseCase = BaseCase(queryIndex, referenceNode.Point(0));
}
// This may be possibly loose for non-ball bound trees.
distances.Lo() = baseCase - referenceNode.FurthestDescendantDistance();
distances.Hi() = baseCase + referenceNode.FurthestDescendantDistance();
// Update last distance calculation.
referenceNode.Stat().LastDistance() = baseCase;
}
else
{
distances = referenceNode.RangeDistance(querySet.unsafe_col(queryIndex));
}
// If the ranges do not overlap, prune this node.
if (!distances.Contains(range))
return DBL_MAX;
// In this case, all of the points in the reference node will be part of the
// results.
if ((distances.Lo() >= range.Lo()) && (distances.Hi() <= range.Hi()))
{
AddResult(queryIndex, referenceNode);
return DBL_MAX; // We don't need to go any deeper.
}
// Otherwise the score doesn't matter. Recursion order is irrelevant in
// range search.
return 0.0;
}
double RangeSearchRules<MetricType, TreeType>::Score(TreeType& queryNode,
TreeType& referenceNode)
{
math::Range distances;
if (tree::TreeTraits<TreeType>::FirstPointIsCentroid)
{
// It is possible that the base case has already been calculated.
double baseCase = 0.0;
bool alreadyDone = false;
if (tree::TreeTraits<TreeType>::HasSelfChildren)
{
TreeType* lastQuery = (TreeType*) referenceNode.Stat().LastDistanceNode();
TreeType* lastRef = (TreeType*) queryNode.Stat().LastDistanceNode();
// Did the query node's last combination do the base case?
if ((lastRef != NULL) && (referenceNode.Point(0) == lastRef->Point(0)))
{
baseCase = queryNode.Stat().LastDistance();
alreadyDone = true;
}
// Did the reference node's last combination do the base case?
if ((lastQuery != NULL) && (queryNode.Point(0) == lastQuery->Point(0)))
{
baseCase = referenceNode.Stat().LastDistance();
alreadyDone = true;
}
// If the query node is a self-child, did the query parent's last
// combination do the base case?
if ((queryNode.Parent() != NULL) &&
(queryNode.Point(0) == queryNode.Parent()->Point(0)))
{
TreeType* lastParentRef = (TreeType*)
queryNode.Parent()->Stat().LastDistanceNode();
if ((lastParentRef != NULL) &&
(referenceNode.Point(0) == lastParentRef->Point(0)))
{
baseCase = queryNode.Parent()->Stat().LastDistance();
alreadyDone = true;
}
}
// If the reference node is a self-child, did the reference parent's last
// combination do the base case?
if ((referenceNode.Parent() != NULL) &&
(referenceNode.Point(0) == referenceNode.Parent()->Point(0)))
{
TreeType* lastQueryRef = (TreeType*)
referenceNode.Parent()->Stat().LastDistanceNode();
if ((lastQueryRef != NULL) &&
(queryNode.Point(0) == lastQueryRef->Point(0)))
{
baseCase = referenceNode.Parent()->Stat().LastDistance();
alreadyDone = true;
}
}
}
if (!alreadyDone)
{
// We must calculate the base case.
baseCase = BaseCase(queryNode.Point(0), referenceNode.Point(0));
}
else
{
// Make sure that if BaseCase() is called, we don't duplicate results.
lastQueryIndex = queryNode.Point(0);
lastReferenceIndex = referenceNode.Point(0);
}
distances.Lo() = baseCase - queryNode.FurthestDescendantDistance()
- referenceNode.FurthestDescendantDistance();
distances.Hi() = baseCase + queryNode.FurthestDescendantDistance()
+ referenceNode.FurthestDescendantDistance();
// Update the last distances performed for the query and reference node.
queryNode.Stat().LastDistanceNode() = (void*) &referenceNode;
queryNode.Stat().LastDistance() = baseCase;
referenceNode.Stat().LastDistanceNode() = (void*) &queryNode;
referenceNode.Stat().LastDistance() = baseCase;
}
else
{
// Just perform the calculation.
distances = referenceNode.RangeDistance(&queryNode);
}
// If the ranges do not overlap, prune this node.
if (!distances.Contains(range))
return DBL_MAX;
// In this case, all of the points in the reference node will be part of all
// the results for each point in the query node.
if ((distances.Lo() >= range.Lo()) && (distances.Hi() <= range.Hi()))
{
for (size_t i = 0; i < queryNode.NumDescendants(); ++i)
AddResult(queryNode.Descendant(i), referenceNode);
return DBL_MAX; // We don't need to go any deeper.
}
// Otherwise the score doesn't matter. Recursion order is irrelevant in range
// search.
return 0.0;
}