Site rightRegion(Halfedge he, Site bottomMostSite) {
Edge edge = he.edge;
if (edge == null) {
return bottomMostSite;
}
return edge.site(LR.other(he.leftRight));
}
public static void main(String[] args) {
LR sgd = new LR(args);
sgd.trainSGD();
sgd.classify();
}
private void fortunesAlgorithm() {
Site newSite, bottomSite, topSite, tempSite;
Vertex v, vertex;
Point newintstar = null;
LR leftRight;
Halfedge lbnd, rbnd, llbnd, rrbnd, bisector;
Edge edge;
Rectangle dataBounds = _sites.getSitesBounds();
int sqrt_nsites = (int) Math.sqrt(_sites.get_length() + 4);
HalfedgePriorityQueue heap =
new HalfedgePriorityQueue(dataBounds.y, dataBounds.height, sqrt_nsites);
EdgeList edgeList = new EdgeList(dataBounds.x, dataBounds.width, sqrt_nsites);
ArrayList<Halfedge> halfEdges = new ArrayList();
ArrayList<Vertex> vertices = new ArrayList();
Site bottomMostSite = _sites.next();
newSite = _sites.next();
for (; ; ) {
if (heap.empty() == false) {
newintstar = heap.min();
}
if (newSite != null && (heap.empty() || compareByYThenX(newSite, newintstar) < 0)) {
/* new site is smallest */
// trace("smallest: new site " + newSite);
// Step 8:
lbnd =
edgeList.edgeListLeftNeighbor(
newSite.get_coord()); // the Halfedge just to the left of newSite
// trace("lbnd: " + lbnd);
rbnd = lbnd.edgeListRightNeighbor; // the Halfedge just to the right
// trace("rbnd: " + rbnd);
bottomSite = rightRegion(lbnd, bottomMostSite); // this is the same as leftRegion(rbnd)
// this Site determines the region containing the new site
// trace("new Site is in region of existing site: " + bottomSite);
// Step 9:
edge = Edge.createBisectingEdge(bottomSite, newSite);
// trace("new edge: " + edge);
_edges.add(edge);
bisector = Halfedge.create(edge, LR.LEFT);
halfEdges.add(bisector);
// inserting two Halfedges into edgeList constitutes Step 10:
// insert bisector to the right of lbnd:
edgeList.insert(lbnd, bisector);
// first half of Step 11:
if ((vertex = Vertex.intersect(lbnd, bisector)) != null) {
vertices.add(vertex);
heap.remove(lbnd);
lbnd.vertex = vertex;
lbnd.ystar = vertex.get_y() + newSite.dist(vertex);
heap.insert(lbnd);
}
lbnd = bisector;
bisector = Halfedge.create(edge, LR.RIGHT);
halfEdges.add(bisector);
// second Halfedge for Step 10:
// insert bisector to the right of lbnd:
edgeList.insert(lbnd, bisector);
// second half of Step 11:
if ((vertex = Vertex.intersect(bisector, rbnd)) != null) {
vertices.add(vertex);
bisector.vertex = vertex;
bisector.ystar = vertex.get_y() + newSite.dist(vertex);
heap.insert(bisector);
}
newSite = _sites.next();
} else if (heap.empty() == false) {
/* intersection is smallest */
lbnd = heap.extractMin();
llbnd = lbnd.edgeListLeftNeighbor;
rbnd = lbnd.edgeListRightNeighbor;
rrbnd = rbnd.edgeListRightNeighbor;
bottomSite = leftRegion(lbnd, bottomMostSite);
topSite = rightRegion(rbnd, bottomMostSite);
// these three sites define a Delaunay triangle
// (not actually using these for anything...)
// _triangles.push(new Triangle(bottomSite, topSite, rightRegion(lbnd)));
v = lbnd.vertex;
v.setIndex();
lbnd.edge.setVertex(lbnd.leftRight, v);
rbnd.edge.setVertex(rbnd.leftRight, v);
edgeList.remove(lbnd);
heap.remove(rbnd);
edgeList.remove(rbnd);
leftRight = LR.LEFT;
if (bottomSite.get_y() > topSite.get_y()) {
tempSite = bottomSite;
bottomSite = topSite;
topSite = tempSite;
leftRight = LR.RIGHT;
}
edge = Edge.createBisectingEdge(bottomSite, topSite);
_edges.add(edge);
bisector = Halfedge.create(edge, leftRight);
halfEdges.add(bisector);
edgeList.insert(llbnd, bisector);
edge.setVertex(LR.other(leftRight), v);
if ((vertex = Vertex.intersect(llbnd, bisector)) != null) {
vertices.add(vertex);
heap.remove(llbnd);
llbnd.vertex = vertex;
llbnd.ystar = vertex.get_y() + bottomSite.dist(vertex);
heap.insert(llbnd);
}
if ((vertex = Vertex.intersect(bisector, rrbnd)) != null) {
vertices.add(vertex);
bisector.vertex = vertex;
bisector.ystar = vertex.get_y() + bottomSite.dist(vertex);
heap.insert(bisector);
}
} else {
break;
}
}
// heap should be empty now
heap.dispose();
edgeList.dispose();
for (Halfedge halfEdge : halfEdges) {
halfEdge.reallyDispose();
}
halfEdges.clear();
// we need the vertices to clip the edges
for (Edge e : _edges) {
e.clipVertices(_plotBounds);
}
// but we don't actually ever use them again!
for (Vertex v0 : vertices) {
v0.dispose();
}
vertices.clear();
}
