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Add EnclosingBall example, update convex hull. 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1563409 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Thomas Neidhart 2014-02-01 12:50:41 +00:00
parent 764f56955d
commit 2933e5773b
2 changed files with 132 additions and 4 deletions
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9
src/userguide/java/org/apache/commons/math3/userguide/geometry/ConvexHullExample.java
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@ -16,7 +16,8 @@ import javax.swing.JComponent;
import org.apache.commons.math3.geometry.euclidean.twod.Vector2D;
import org.apache.commons.math3.geometry.euclidean.twod.hull.ConvexHull2D;
import org.apache.commons.math3.geometry.euclidean.twod.hull.GrahamScan;
import org.apache.commons.math3.geometry.euclidean.twod.hull.ConvexHullGenerator2D;
import org.apache.commons.math3.geometry.euclidean.twod.hull.MonotoneChain;
import org.apache.commons.math3.random.MersenneTwister;
import org.apache.commons.math3.random.RandomGenerator;
import org.apache.commons.math3.userguide.ExampleUtils;
@ -28,7 +29,7 @@ import org.apache.commons.math3.userguide.ExampleUtils.ExampleFrame;
public class ConvexHullExample {
public static List<Vector2D> createRandomPoints(int size) {
RandomGenerator random = new MersenneTwister(10);
RandomGenerator random = new MersenneTwister();
// create the cloud container
List<Vector2D> points = new ArrayList<Vector2D>(size);
@ -43,12 +44,12 @@ public class ConvexHullExample {
public static class Display extends ExampleFrame {
public Display() {
setTitle("Commons-Math: Convex Hull examples");
setTitle("Commons-Math: Convex Hull example");
setSize(400, 400);
setLayout(new FlowLayout());
GrahamScan generator = new GrahamScan();
ConvexHullGenerator2D generator = new MonotoneChain();
Collection<Vector2D> cloud = createRandomPoints(150);
ConvexHull2D hull = generator.generate(cloud);

127
src/userguide/java/org/apache/commons/math3/userguide/geometry/EnclosingBallExample.java Normal file
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@ -0,0 +1,127 @@
package org.apache.commons.math3.userguide.geometry;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import javax.swing.JComponent;
import org.apache.commons.math3.geometry.enclosing.Encloser;
import org.apache.commons.math3.geometry.enclosing.EnclosingBall;
import org.apache.commons.math3.geometry.enclosing.WelzlEncloser;
import org.apache.commons.math3.geometry.euclidean.twod.DiskGenerator;
import org.apache.commons.math3.geometry.euclidean.twod.Euclidean2D;
import org.apache.commons.math3.geometry.euclidean.twod.Vector2D;
import org.apache.commons.math3.random.MersenneTwister;
import org.apache.commons.math3.random.RandomGenerator;
import org.apache.commons.math3.userguide.ExampleUtils;
import org.apache.commons.math3.userguide.ExampleUtils.ExampleFrame;
/**
* Shows how to generate the convex hull of a point cloud in 2D.
*/
public class EnclosingBallExample {
public static List<Vector2D> createRandomPoints(int size) {
RandomGenerator random = new MersenneTwister();
// create the cloud container
List<Vector2D> points = new ArrayList<Vector2D>(size);
// fill the cloud with a random distribution of points
for (int i = 0; i < size; i++) {
points.add(new Vector2D(random.nextDouble() - 0.5, random.nextDouble() - 0.5));
}
return points;
}
@SuppressWarnings("serial")
public static class Display extends ExampleFrame {
public Display() {
setTitle("Commons-Math: Enclosing Ball example");
setSize(400, 400);
setLayout(new FlowLayout());
Collection<Vector2D> cloud = createRandomPoints(150);
Encloser<Euclidean2D, Vector2D> encloser = new WelzlEncloser<Euclidean2D, Vector2D>(1e-10, new DiskGenerator());
EnclosingBall<Euclidean2D, Vector2D> ball = encloser.enclose(cloud);
add(new Plot(cloud, ball));
}
}
@SuppressWarnings("serial")
public static class Plot extends JComponent {
private static double PAD = 10;
private Iterable<Vector2D> cloud;
private EnclosingBall<Euclidean2D, Vector2D> ball;
public Plot(Iterable<Vector2D> cloud, EnclosingBall<Euclidean2D, Vector2D> ball) {
this.cloud = cloud;
this.ball = ball;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int w = getWidth();
int h = getHeight();
g2.clearRect(0, 0, w, h);
g2.setPaint(Color.black);
g2.drawRect(0, 0, w - 1, h - 1);
for (Vector2D point : cloud) {
drawPoint(g2, point, w, h);
}
g.setColor(Color.RED);
drawCircle(g2, ball.getCenter(), ball.getRadius(), w, h);
}
private void drawPoint(Graphics2D g2, Vector2D point, int width, int height) {
Vector2D p = transform(point, width, height);
double[] arr = p.toArray();
g2.draw(new Rectangle2D.Double(arr[0] - 1, arr[1] - 1, 2, 2));
}
public void drawCircle(Graphics2D g2, Vector2D center, double radius, int width, int height) {
Vector2D c = transform(center, width, height);
double[] arr = c.toArray();
double rx = (radius) / 2 * (width - 2 * PAD);
double ry = (radius) / 2 * (height - 2 * PAD);
g2.draw(new Ellipse2D.Double(arr[0] - rx, arr[1] - ry, rx * 2, ry * 2));
}
@Override
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
private Vector2D transform(Vector2D point, int width, int height) {
double[] arr = point.toArray();
return new Vector2D(new double[] { PAD + (arr[0] + 0.5) / 2 * (width - 2 * PAD) + width / 4,
height - PAD - (arr[1] + 0.5) / 2 * (height - 2 * PAD) - height / 4 });
}
}
public static void main(String[] args) {
ExampleUtils.showExampleFrame(new Display());
}
}