package de.lmu.ifi.dbs.elki.visualization.visualizers.scatterplot.cluster;
/*
This file is part of ELKI:
Environment for Developing KDD-Applications Supported by Index-Structures
Copyright (C) 2011
Ludwig-Maximilians-Universität München
Lehr- und Forschungseinheit für Datenbanksysteme
ELKI Development Team
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import org.apache.batik.util.SVGConstants;
import org.w3c.dom.Element;
import de.lmu.ifi.dbs.elki.data.Cluster;
import de.lmu.ifi.dbs.elki.data.Clustering;
import de.lmu.ifi.dbs.elki.data.model.Model;
import de.lmu.ifi.dbs.elki.data.spatial.Polygon;
import de.lmu.ifi.dbs.elki.data.spatial.SpatialUtil;
import de.lmu.ifi.dbs.elki.database.ids.DBID;
import de.lmu.ifi.dbs.elki.database.ids.DBIDs;
import de.lmu.ifi.dbs.elki.math.geometry.AlphaShape;
import de.lmu.ifi.dbs.elki.math.geometry.GrahamScanConvexHull2D;
import de.lmu.ifi.dbs.elki.math.linearalgebra.Vector;
import de.lmu.ifi.dbs.elki.result.HierarchicalResult;
import de.lmu.ifi.dbs.elki.result.Result;
import de.lmu.ifi.dbs.elki.result.ResultUtil;
import de.lmu.ifi.dbs.elki.utilities.iterator.IterableIterator;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.OptionID;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.Parameterization;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.DoubleParameter;
import de.lmu.ifi.dbs.elki.visualization.VisualizationTask;
import de.lmu.ifi.dbs.elki.visualization.colors.ColorLibrary;
import de.lmu.ifi.dbs.elki.visualization.css.CSSClass;
import de.lmu.ifi.dbs.elki.visualization.projections.CanvasSize;
import de.lmu.ifi.dbs.elki.visualization.projections.Projection;
import de.lmu.ifi.dbs.elki.visualization.projector.ScatterPlotProjector;
import de.lmu.ifi.dbs.elki.visualization.style.StyleLibrary;
import de.lmu.ifi.dbs.elki.visualization.svg.SVGPath;
import de.lmu.ifi.dbs.elki.visualization.svg.SVGPlot;
import de.lmu.ifi.dbs.elki.visualization.svg.SVGUtil;
import de.lmu.ifi.dbs.elki.visualization.visualizers.AbstractVisFactory;
import de.lmu.ifi.dbs.elki.visualization.visualizers.Visualization;
import de.lmu.ifi.dbs.elki.visualization.visualizers.scatterplot.AbstractScatterplotVisualization;
/**
* Visualizer for generating an SVG-Element containing the convex hull / alpha
* shape of each cluster.
*
* @author Robert Rödler
* @author Erich Schubert
*
* @apiviz.has Clustering oneway - - visualizes
* @apiviz.uses ConvexHull2D
* @apiviz.uses AlphaShape
*/
public class ClusterHullVisualization extends AbstractScatterplotVisualization {
/**
* A short name characterizing this Visualizer.
*/
private static final String NAME = "Cluster Hull Visualization";
/**
* Generic tags to indicate the type of element. Used in IDs, CSS-Classes etc.
*/
public static final String CLUSTERHULL = "cluster-hull";
/**
* The result we work on
*/
Clustering<Model> clustering;
/**
* Alpha value
*/
double alpha = Double.POSITIVE_INFINITY;
/**
* Constructor
*
* @param task VisualizationTask
* @param alpha Alpha value
*/
public ClusterHullVisualization(VisualizationTask task, double alpha) {
super(task);
this.clustering = task.getResult();
this.alpha = alpha;
incrementalRedraw();
}
@Override
protected void redraw() {
// Viewport size, for "relative size" computations
final CanvasSize viewp = proj.estimateViewport();
double projarea = viewp.getDiffX() * viewp.getDiffY();
double opacity = 0.25;
Iterator<Cluster<Model>> ci = clustering.getAllClusters().iterator();
for(int cnum = 0; cnum < clustering.getAllClusters().size(); cnum++) {
Cluster<?> clus = ci.next();
final DBIDs ids = clus.getIDs();
if(alpha >= Double.POSITIVE_INFINITY) {
GrahamScanConvexHull2D hull = new GrahamScanConvexHull2D();
for(DBID clpnum : ids) {
double[] projP = proj.fastProjectDataToRenderSpace(rel.get(clpnum));
hull.add(new Vector(projP));
}
Polygon chres = hull.getHull();
// Plot the convex hull:
if(chres != null && chres.size() > 1) {
SVGPath path = new SVGPath(chres);
// Approximate area (using bounding box)
double hullarea = SpatialUtil.volume(chres);
final double relativeArea = (projarea - hullarea) / projarea;
final double relativeSize = (double) ids.size() / rel.size();
opacity = Math.sqrt(relativeSize * relativeArea);
Element hulls = path.makeElement(svgp);
addCSSClasses(svgp, cnum, opacity);
SVGUtil.addCSSClass(hulls, CLUSTERHULL + cnum);
layer.appendChild(hulls);
}
}
else {
ArrayList<Vector> ps = new ArrayList<Vector>(ids.size());
for(DBID clpnum : ids) {
double[] projP = proj.fastProjectDataToRenderSpace(rel.get(clpnum));
ps.add(new Vector(projP));
}
List<Polygon> polys = (new AlphaShape(ps, alpha * Projection.SCALE)).compute();
for(Polygon p : polys) {
SVGPath path = new SVGPath(p);
Element hulls = path.makeElement(svgp);
addCSSClasses(svgp, cnum, 0.5);
SVGUtil.addCSSClass(hulls, CLUSTERHULL + cnum);
layer.appendChild(hulls);
}
}
}
}
/**
* Adds the required CSS-Classes
*
* @param svgp SVG-Plot
*/
private void addCSSClasses(SVGPlot svgp, int clusterID, double opac) {
ColorLibrary colors = context.getStyleLibrary().getColorSet(StyleLibrary.PLOT);
CSSClass cls = new CSSClass(this, CLUSTERHULL + clusterID);
cls.setStatement(SVGConstants.CSS_STROKE_WIDTH_PROPERTY, context.getStyleLibrary().getLineWidth(StyleLibrary.PLOT));
final String color;
if(clustering.getAllClusters().size() == 1) {
color = "black";
}
else {
color = colors.getColor(clusterID);
}
cls.setStatement(SVGConstants.CSS_STROKE_PROPERTY, color);
cls.setStatement(SVGConstants.CSS_FILL_PROPERTY, color);
cls.setStatement(SVGConstants.CSS_FILL_OPACITY_PROPERTY, opac);
svgp.addCSSClassOrLogError(cls);
}
/**
* Factory for visualizers to generate an SVG-Element containing the convex
* hull or alpha shape of a cluster.
*
* @author Robert Rödler
* @author Erich Schubert
*
* @apiviz.stereotype factory
* @apiviz.uses ClusterHullVisualization oneway - - «create»
*/
public static class Factory extends AbstractVisFactory {
/**
* Alpha value
*/
double alpha = Double.POSITIVE_INFINITY;
/**
* Constructor.
*
* @param alpha Alpha value
*/
public Factory(double alpha) {
super();
this.alpha = alpha;
}
@Override
public Visualization makeVisualization(VisualizationTask task) {
return new ClusterHullVisualization(task, alpha);
}
@Override
public void processNewResult(HierarchicalResult baseResult, Result result) {
// Find clusterings we can visualize:
Collection<Clustering<?>> clusterings = ResultUtil.filterResults(result, Clustering.class);
for(Clustering<?> c : clusterings) {
IterableIterator<ScatterPlotProjector<?>> ps = ResultUtil.filteredResults(baseResult, ScatterPlotProjector.class);
for(ScatterPlotProjector<?> p : ps) {
final VisualizationTask task = new VisualizationTask(NAME, c, p.getRelation(), this);
task.put(VisualizationTask.META_LEVEL, VisualizationTask.LEVEL_DATA - 1);
task.put(VisualizationTask.META_VISIBLE_DEFAULT, false);
baseResult.getHierarchy().add(c, task);
baseResult.getHierarchy().add(p, task);
}
}
}
/**
* Parameterization class.
*
* @author Erich Schubert
*
* @apiviz.exclude
*/
public static class Parameterizer extends AbstractParameterizer {
/**
* Alpha-Value for alpha-shapes
*
* <p>
* Key: {@code -hull.alpha}
* </p>
*/
public static final OptionID ALPHA_ID = OptionID.getOrCreateOptionID("hull.alpha", "Alpha value for hull drawing (in projected space!).");
/**
* Alpha value
*/
double alpha = Double.POSITIVE_INFINITY;
@Override
protected void makeOptions(Parameterization config) {
super.makeOptions(config);
DoubleParameter alphaP = new DoubleParameter(ALPHA_ID, Double.POSITIVE_INFINITY);
if(config.grab(alphaP)) {
alpha = alphaP.getValue();
}
}
@Override
protected Factory makeInstance() {
return new Factory(alpha);
}
}
}
}