/* traverse the quadtree to find the best renking cluster */
static void findBestCluster(layerObj* layer, msClusterLayerInfo* layerinfo, clusterTreeNode *node)
{
int i;
double rank;
clusterInfo* s = node->shapes;
while (s) {
if (s->filter < 0 && layer->cluster.filter.string != NULL) {
InitShapeAttributes(layer, s);
s->filter = msClusterEvaluateFilter(&layer->cluster.filter, &s->shape);
}
if (s->numsiblings == 0 || s->filter == 0) {
/* individual or filtered shapes must be removed for sure */
layerinfo->current = s;
return;
}
/* calculating the rank */
rank = (s->x - s->avgx) * (s->x - s->avgx) + (s->y - s->avgy) * (s->y - s->avgy) /*+ s->varx + s->vary*/ + (double)1/ (1 + s->numsiblings);
if (rank < layerinfo->rank) {
layerinfo->current = s;
layerinfo->rank = rank;
}
s = s->next;
}
/* Recurse to subnodes if they exist */
for (i = 0; i < 4; i++) {
if (node->subnode[i])
findBestCluster(layer, layerinfo, node->subnode[i]);
}
}
void clusterize(int k, entryList &l) {
printf("Clusterizing in %d clusters\n", k);
cluster *clusters = new cluster[k];
selectSeeds(clusters, l, k);
double RSS = printRSS(clusters, k);
double prevRSS = 1e+20;
int iterations = 0;
while(iterations < MAX_ITERATIONS && (prevRSS - RSS) > THRESHOLD) {
iterations++;
printf("Iteration %d\n", iterations);
// Clear cluster members.
for(int i=0; i<k; i++)
clusters[i].members.clear();
// Find the best cluster for each entry
// and add as a member
for(int i=0; i<l.size(); i++) {
article_entry* entry = l.get(i);
cluster& cl = findBestCluster(clusters, k, entry->v);
cl.members.add(entry);
}
// Recompute centroids
printf("Computing centroids ");
for(int i=0; i<k; i++) {
printf("%d ", i);
recomputeCentroid(clusters[i]);
}
printf("\n");
prevRSS = RSS;
RSS = printRSS(clusters, k);
}
delete[] clusters;
}
/* rebuild the clusters according to the current extent */
int RebuildClusters(layerObj *layer, int isQuery)
{
mapObj* map;
layerObj* srcLayer;
double distance, maxDistanceX, maxDistanceY, cellSizeX, cellSizeY;
rectObj searchrect;
int status;
clusterInfo* current;
int depth;
#ifdef USE_CLUSTER_EXTERNAL
int layerIndex;
#endif
msClusterLayerInfo* layerinfo = layer->layerinfo;
if (!layerinfo) {
msSetError(MS_MISCERR, "Layer is not open: %s", "RebuildClusters()", layer->name);
return MS_FAILURE;
}
if (!layer->map) {
msSetError(MS_MISCERR, "No map associated with this layer: %s", "RebuildClusters()", layer->name);
return MS_FAILURE;
}
if (layer->debug >= MS_DEBUGLEVEL_VVV)
msDebug("Clustering started.\n");
map = layer->map;
layerinfo->current = layerinfo->finalized; /* restart */
/* check whether all shapes should be returned from a query */
if(msLayerGetProcessingKey(layer, "CLUSTER_GET_ALL_SHAPES") != NULL)
layerinfo->get_all_shapes = MS_TRUE;
else
layerinfo->get_all_shapes = MS_FALSE;
/* identify the current extent */
if(layer->transform == MS_TRUE)
searchrect = map->extent;
else {
searchrect.minx = searchrect.miny = 0;
searchrect.maxx = map->width-1;
searchrect.maxy = map->height-1;
}
if (searchrect.minx == layerinfo->searchRect.minx &&
searchrect.miny == layerinfo->searchRect.miny &&
searchrect.maxx == layerinfo->searchRect.maxx &&
searchrect.maxy == layerinfo->searchRect.maxy) {
/* already built */
return MS_SUCCESS;
}
/* destroy previous data*/
clusterDestroyData(layerinfo);
layerinfo->searchRect = searchrect;
/* reproject the rectangle to layer coordinates */
#ifdef USE_PROJ
if((map->projection.numargs > 0) && (layer->projection.numargs > 0))
msProjectRect(&map->projection, &layer->projection, &searchrect); /* project the searchrect to source coords */
#endif
/* determine the compare method */
layerinfo->fnCompare = CompareRectangleRegion;
if (layer->cluster.region) {
if (EQUAL(layer->cluster.region, "ellipse"))
layerinfo->fnCompare = CompareEllipseRegion;
}
/* trying to find a reasonable quadtree depth */
depth = 0;
distance = layer->cluster.maxdistance;
while ((distance < map->width || distance < map->height) && depth <= TREE_MAX_DEPTH) {
distance *= 2;
++depth;
}
layerinfo->depth = depth;
cellSizeX = MS_CELLSIZE(searchrect.minx, searchrect.maxx, map->width);
cellSizeY = MS_CELLSIZE(searchrect.miny, searchrect.maxy, map->height);
maxDistanceX = layer->cluster.maxdistance * cellSizeX;
maxDistanceY = layer->cluster.maxdistance * cellSizeY;
/* increase the search rectangle so that the neighbouring shapes are also retrieved */
searchrect.minx -= layer->cluster.buffer * cellSizeX;
searchrect.maxx += layer->cluster.buffer * cellSizeX;
searchrect.miny -= layer->cluster.buffer * cellSizeY;
searchrect.maxy += layer->cluster.buffer * cellSizeY;
/* create the root node */
if (layerinfo->root)
clusterTreeNodeDestroy(layerinfo, layerinfo->root);
layerinfo->root = clusterTreeNodeCreate(layerinfo, searchrect);
srcLayer = &layerinfo->srcLayer;
/* start retrieving the shapes */
status = msLayerWhichShapes(srcLayer, searchrect, isQuery);
if(status == MS_DONE) {
/* no overlap */
return MS_SUCCESS;
} else if(status != MS_SUCCESS) {
return MS_FAILURE;
}
/* step through the source shapes and populate the quadtree with the tentative clusters */
if ((current = clusterInfoCreate(layerinfo)) == NULL)
return MS_FAILURE;
while((status = msLayerNextShape(srcLayer, ¤t->shape)) == MS_SUCCESS) {
#if defined(USE_PROJ) && defined(USE_CLUSTER_EXTERNAL)
/* transform the shape to the projection of this layer */
if(srcLayer->transform == MS_TRUE && srcLayer->project && layer->transform == MS_TRUE && layer->project &&msProjectionsDiffer(&(srcLayer->projection), &(layer->projection)))
msProjectShape(&srcLayer->projection, &layer->projection, ¤t->shape);
#endif
/* set up positions and variance */
current->avgx = current->x = current->shape.bounds.minx;
current->avgy = current->y = current->shape.bounds.miny;
current->varx = current->vary = 0;
/* set up the area of interest when searching for the neighboring shapes */
current->bounds.minx = current->x - maxDistanceX;
current->bounds.miny = current->y - maxDistanceY;
current->bounds.maxx = current->x + maxDistanceX;
current->bounds.maxy = current->y + maxDistanceY;
/* if the shape doesn't overlap we must skip it to avoid further issues */
if(!msRectOverlap(&searchrect, ¤t->bounds)) {
msFreeShape(¤t->shape);
msInitShape(¤t->shape);
msDebug("Skipping an invalid shape falling outside of the given extent\n");
continue;
}
/* construct the item array */
if (layer->iteminfo)
BuildFeatureAttributes(layer, layerinfo, ¤t->shape);
/* evaluate the group expression */
if (layer->cluster.group.string)
current->group = msClusterGetGroupText(&layer->cluster.group, ¤t->shape);
/*start a query for the related shapes */
findRelatedShapes(layerinfo, layerinfo->root, current);
/* add this shape to the tree */
if (treeNodeAddShape(layerinfo, layerinfo->root, current, depth) != MS_SUCCESS) {
clusterInfoDestroyList(layerinfo, current);
return MS_FAILURE;
}
if ((current = clusterInfoCreate(layerinfo)) == NULL) {
clusterInfoDestroyList(layerinfo, current);
return MS_FAILURE;
}
}
clusterInfoDestroyList(layerinfo, current);
while (layerinfo->root) {
#ifdef TESTCOUNT
int n;
double avgx, avgy;
#endif
/* pick up the best cluster from the tree and do the finalization */
/* the initial rank must be big enough */
layerinfo->rank = (searchrect.maxx - searchrect.minx) * (searchrect.maxx - searchrect.minx) +
(searchrect.maxy - searchrect.miny) * (searchrect.maxy - searchrect.miny) + 1;
layerinfo->current = NULL;
findBestCluster(layer, layerinfo, layerinfo->root);
if (layerinfo->current == NULL) {
if (layer->debug >= MS_DEBUGLEVEL_VVV)
msDebug("Clustering terminated.\n");
break; /* completed */
}
/* Update the feature count of the shape */
InitShapeAttributes(layer, layerinfo->current);
/* collecting the shapes of the cluster */
collectClusterShapes(layerinfo, layerinfo->root, layerinfo->current);
if (layer->debug >= MS_DEBUGLEVEL_VVV) {
msDebug("processing cluster %p: rank=%lf fcount=%d ncoll=%d nfin=%d nfins=%d nflt=%d bounds={%lf %lf %lf %lf}\n", layerinfo->current, layerinfo->rank, layerinfo->current->numsiblings + 1,
layerinfo->current->numcollected, layerinfo->numFinalized, layerinfo->numFinalizedSiblings,
layerinfo->numFiltered, layerinfo->current->bounds.minx, layerinfo->current->bounds.miny,
layerinfo->current->bounds.maxx, layerinfo->current->bounds.maxy);
if (layerinfo->current->node) {
char pszBuffer[TREE_MAX_DEPTH + 1];
clusterTreeNode* node = layerinfo->current->node;
int position = node->position;
int i = 1;
while (position > 0 && i <= TREE_MAX_DEPTH) {
pszBuffer[TREE_MAX_DEPTH - i] = '0' + (position % 4);
position = position >> 2;
++i;
}
pszBuffer[TREE_MAX_DEPTH] = 0;
msDebug(" ->node %p: count=%d index=%d pos=%s subn={%p %p %p %p} rect={%lf %lf %lf %lf}\n",
node, node->numshapes, node->index, pszBuffer + TREE_MAX_DEPTH - i + 1,
node->subnode[0], node->subnode[1], node->subnode[2], node->subnode[3],
node->rect.minx, node->rect.miny, node->rect.maxx, node->rect.maxy);
}
}
