https://github.com/jonghough/javagraph
A collection of graph algorithms
https://github.com/jonghough/javagraph
algorithm astar-algorithm dijkstra geometry graph graph-algorithms graph-theory graph-types graphs java undirected-graphs voronoi-diagram
Last synced: 10 months ago
JSON representation
A collection of graph algorithms
- Host: GitHub
- URL: https://github.com/jonghough/javagraph
- Owner: jonghough
- License: mit
- Created: 2016-03-12T13:15:39.000Z (over 9 years ago)
- Default Branch: master
- Last Pushed: 2016-08-21T11:49:00.000Z (over 9 years ago)
- Last Synced: 2025-01-10T02:25:54.978Z (11 months ago)
- Topics: algorithm, astar-algorithm, dijkstra, geometry, graph, graph-algorithms, graph-theory, graph-types, graphs, java, undirected-graphs, voronoi-diagram
- Language: Java
- Size: 2.13 MB
- Stars: 0
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
[](https://travis-ci.org/jonghough/JavaGraph) []()
# Java Graph Library
## A collection of algorithms and datatypes for working with Graphs
### Build
`mvn clean install`
### Run tests
`mvn test`
## Overview
### Searching, Spanning, Cutting
* Dijkstra's algorithm for undirected graphs
* A*-algorithm for undirected graphs
* Bellman-Ford algorithm for directed graphs
* Ford-Fulkerson algorithm, for flow networks
* Minimum spanning tree algorithm
* Cycle finding algorithm
* MinCut algorithm to find minimum cut
### Geometry
#### Voronoi Diagrams
The library contains classes to construct Voronoi Diagrams from arbitray collections of 2D points. To create Voronoi diagrams
an implementation of *Fortune's algorithm* is used, with time complexity *~O(n log n)*.
#### Examples
It is easy to create a voronoi diagram, for example, using `JavaFX`:
```
public class VoronoiViewer extends Application {
static ArrayList nodeList;
public static VoronoiGenerator voronoi;
public static void main(String[] args) {
Random r = new Random();
nodeList = new ArrayList();
for(int j = 0; j < 34; j++){
for(int k = 0; k < 14; k++){
nodeList.add(new Node2d(3 + j*25 + 0.000*r.nextInt(663), 4 + k * 30+ j*j*0.25 + 0*r.nextInt(470)));
}
}
voronoi = new VoronoiGenerator(nodeList);
voronoi.createDiagram();
launch(args);
}
@Override
public void start(Stage primaryStage) throws Exception {
primaryStage.setTitle("Voronoi Test");
Group root = new Group();
Canvas canvas = new Canvas(800, 750);
GraphicsContext gc = canvas.getGraphicsContext2D();
gc.setStroke(Color.MAROON);
int total = 0;
double r = 0.5;
double g = 0.0;
double b = 1.0;
for(int i = 0; i < voronoi.getNodes().size(); i ++){
Node2d ce = voronoi.getNodes().get(i);
HalfEdge edge= ce.halfEdge;
HalfEdge f = edge;
gc.setStroke(Color.color(r,g,b));
gc.beginPath();
while(edge != null){
total++;
gc.setStroke(Color.color(r,g,b));
gc.beginPath();
gc.moveTo(edge.twin().getTarget().getX(), edge.twin().getTarget().getY());
gc.lineTo(edge.getTarget().getX(), edge.getTarget().getY());
gc.stroke();
edge = edge.next();
if(edge == null || f == edge)
break;
}
}
gc.setFill(Color.FIREBRICK);
for (CircleEvent ce : voronoi.getAllCircleEvents()) {
gc.setFill(Color.DEEPPINK);
gc.fillOval(ce.getX()-2, ce.getY()-2, 4, 4);
gc.setStroke(Color.BLACK);
}
gc.setFill(Color.RED);
for (Node2d n : nodeList) {
gc.fillOval(n.getX() - 5f / 2, n.getY() - 5f / 2, 5, 5);
}
root.getChildren().add(canvas);
Scene scene = new Scene(root);
scene.setFill(Color.OLDLACE);
primaryStage.setScene(scene);
primaryStage.show();
}
}
```
### Graph structure
* Construction of various graph types of given size.
* Chromatic number estimations
* Graph colorizable algorithm
* Chromatic polynomials for certain graph types
* Construct Line graph **L(G)** of graph
### Others
* Genetic algorithm solution to TSP problem for a given **complete** graph.