org.jgrapht.alg.drawing.RandomLayoutAlgorithm2D Maven / Gradle / Ivy
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/*
* (C) Copyright 2018-2023, by Dimitrios Michail and Contributors.
*
* JGraphT : a free Java graph-theory library
*
* See the CONTRIBUTORS.md file distributed with this work for additional
* information regarding copyright ownership.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0, or the
* GNU Lesser General Public License v2.1 or later
* which is available at
* http://www.gnu.org/licenses/old-licenses/lgpl-2.1-standalone.html.
*
* SPDX-License-Identifier: EPL-2.0 OR LGPL-2.1-or-later
*/
package org.jgrapht.alg.drawing;
import org.jgrapht.*;
import org.jgrapht.alg.drawing.model.*;
import java.util.*;
/**
* Random layout. The algorithm assigns vertex coordinates uniformly at random.
*
* @author Dimitrios Michail
*
* @param the vertex type
* @param the edge type
*/
public class RandomLayoutAlgorithm2D
extends BaseLayoutAlgorithm2D
{
private Random rng;
/**
* Create a new layout algorithm
*/
public RandomLayoutAlgorithm2D()
{
this(new Random());
}
/**
* Create a new layout algorithm
*
* @param seed seed for the random number generator
*/
public RandomLayoutAlgorithm2D(long seed)
{
this(new Random(seed));
}
/**
* Create a new layout algorithm
*
* @param rng the random number generator
*/
public RandomLayoutAlgorithm2D(Random rng)
{
this.rng = Objects.requireNonNull(rng, "Random number generator cannot be null");
}
@Override
public void layout(Graph graph, LayoutModel2D model)
{
super.init(graph, model);
Box2D drawableArea = model.getDrawableArea();
double minX = drawableArea.getMinX();
double minY = drawableArea.getMinX();
double width = drawableArea.getWidth();
double height = drawableArea.getHeight();
for (V v : graph.vertexSet()) {
double x = rng.nextDouble() * width;
double y = rng.nextDouble() * height;
model.put(v, Point2D.of(minX + x, minY + y));
}
}
}