private double getAreaEnlargement(Node indexNode, Node geomRootNode) {
Envelope before = getIndexNodeEnvelope(indexNode);
Envelope after = getLeafNodeEnvelope(geomRootNode);
after.expandToInclude(before);
return getArea(after) - getArea(before);
}
public double measure(Geometry g1, Geometry g2) {
double distance = DiscreteHausdorffDistance.distance(g1, g2, DENSIFY_FRACTION);
Envelope env = new Envelope(g1.getEnvelopeInternal());
env.expandToInclude(g2.getEnvelopeInternal());
double envSize = diagonalSize(env);
// normalize so that more similarity produces a measure closer to 1
double measure = 1 - distance / envSize;
// System.out.println("Hausdorff distance = " + distance + ", measure = " + measure);
return measure;
}
/**
* Enlarges this <code>Envelope</code> so that it contains the <code>other</code> Envelope. Has no
* effect if <code>other</code> is wholly on or within the envelope.
*
* @param other the <code>Envelope</code> to expand to include
*/
@Override
public void expandToInclude(final Envelope other) {
if (other.isNull()) {
return;
}
double otherMinZ = getMinZOf(other);
double otherMaxZ = getMaxZOf(other);
if (isNull()) {
super.expandToInclude(other);
minz = otherMinZ;
maxz = otherMaxZ;
} else {
super.expandToInclude(other);
if (otherMinZ < minz) {
minz = otherMinZ;
}
if (otherMaxZ > maxz) {
maxz = otherMaxZ;
}
}
}
/**
* Fix an IndexNode bounding box after a child has been removed
*
* @param indexNode
* @return true if something has changed
*/
private boolean adjustParentBoundingBox(Node indexNode, RelationshipType relationshipType) {
double[] old = null;
if (indexNode.hasProperty(INDEX_PROP_BBOX)) {
old = (double[]) indexNode.getProperty(INDEX_PROP_BBOX);
}
Envelope bbox = null;
Iterator<Relationship> iterator =
indexNode.getRelationships(relationshipType, Direction.OUTGOING).iterator();
while (iterator.hasNext()) {
Node childNode = iterator.next().getEndNode();
if (bbox == null) {
bbox = new Envelope(getChildNodeEnvelope(childNode, relationshipType));
} else {
bbox.expandToInclude(getChildNodeEnvelope(childNode, relationshipType));
}
}
if (bbox == null) {
// this could happen in an empty tree
bbox = new Envelope(0, 0, 0, 0);
}
if (old.length != 4
|| bbox.getMinX() != old[0]
|| bbox.getMinY() != old[1]
|| bbox.getMaxX() != old[2]
|| bbox.getMaxY() != old[3]) {
indexNode.setProperty(
INDEX_PROP_BBOX,
new double[] {bbox.getMinX(), bbox.getMinY(), bbox.getMaxX(), bbox.getMaxY()});
return true;
} else {
return false;
}
}
/** Create a bounding box encompassing the two bounding boxes passed in. */
private static Envelope createEnvelope(Envelope e, Envelope e1) {
Envelope result = new Envelope(e);
result.expandToInclude(e1);
return result;
}
private Node quadraticSplit(Node indexNode, RelationshipType relationshipType) {
List<Node> entries = new ArrayList<Node>();
Iterable<Relationship> relationships =
indexNode.getRelationships(relationshipType, Direction.OUTGOING);
for (Relationship relationship : relationships) {
entries.add(relationship.getEndNode());
relationship.delete();
}
// pick two seed entries such that the dead space is maximal
Node seed1 = null;
Node seed2 = null;
double worst = Double.NEGATIVE_INFINITY;
for (int i = 0; i < entries.size(); ++i) {
Node e = entries.get(i);
Envelope eEnvelope = getChildNodeEnvelope(e, relationshipType);
for (int j = i + 1; j < entries.size(); ++j) {
Node e1 = entries.get(j);
Envelope e1Envelope = getChildNodeEnvelope(e1, relationshipType);
double deadSpace =
getArea(createEnvelope(eEnvelope, e1Envelope))
- getArea(eEnvelope)
- getArea(e1Envelope);
if (deadSpace > worst) {
worst = deadSpace;
seed1 = e;
seed2 = e1;
}
}
}
List<Node> group1 = new ArrayList<Node>();
group1.add(seed1);
Envelope group1envelope = getChildNodeEnvelope(seed1, relationshipType);
List<Node> group2 = new ArrayList<Node>();
group2.add(seed2);
Envelope group2envelope = getChildNodeEnvelope(seed2, relationshipType);
entries.remove(seed1);
entries.remove(seed2);
while (entries.size() > 0) {
// compute the cost of inserting each entry
List<Node> bestGroup = null;
Envelope bestGroupEnvelope = null;
Node bestEntry = null;
double expansionMin = Double.POSITIVE_INFINITY;
for (Node e : entries) {
Envelope nodeEnvelope = getChildNodeEnvelope(e, relationshipType);
double expansion1 =
getArea(createEnvelope(nodeEnvelope, group1envelope)) - getArea(group1envelope);
double expansion2 =
getArea(createEnvelope(nodeEnvelope, group2envelope)) - getArea(group2envelope);
if (expansion1 < expansion2 && expansion1 < expansionMin) {
bestGroup = group1;
bestGroupEnvelope = group1envelope;
bestEntry = e;
expansionMin = expansion1;
} else if (expansion2 < expansion1 && expansion2 < expansionMin) {
bestGroup = group2;
bestGroupEnvelope = group2envelope;
bestEntry = e;
expansionMin = expansion2;
} else if (expansion1 == expansion2 && expansion1 < expansionMin) {
// in case of equality choose the group with the smallest area
if (getArea(group1envelope) < getArea(group2envelope)) {
bestGroup = group1;
bestGroupEnvelope = group1envelope;
} else {
bestGroup = group2;
bestGroupEnvelope = group2envelope;
}
bestEntry = e;
expansionMin = expansion1;
}
}
// insert the best candidate entry in the best group
bestGroup.add(bestEntry);
bestGroupEnvelope.expandToInclude(getChildNodeEnvelope(bestEntry, relationshipType));
entries.remove(bestEntry);
}
// reset bounding box and add new children
indexNode.removeProperty(INDEX_PROP_BBOX);
for (Node node : group1) {
addChild(indexNode, relationshipType, node);
}
// create new node from split
Node newIndexNode = database.createNode();
for (Node node : group2) {
addChild(newIndexNode, relationshipType, node);
}
return newIndexNode;
}
public Envelope expandEnvelope(Envelope env) {
for (int i = 0; i < coordinates.length; i++) {
env.expandToInclude(coordinates[i]);
}
return env;
}
