Jcg.graph.arraybased

Class ArrayBasedGraphLoader

java.lang.Object

Jcg.graph.arraybased.ArrayBasedGraphLoader

public class ArrayBasedGraphLoader
extends java.lang.Object

This class provides input/output methods for reading (writing) graph structures to (from) files

Author:

Luca Castelli Aleardi (Ecole Polytechnique, 2014)

Constructor Summary

Constructors

Constructor and Description
ArrayBasedGraphLoader()

Method Summary

Modifier and Type	Method and Description
static ArrayBasedGraph	constructFromPolyhedron(Polyhedron_3<Point_> polyhedron) Construct the graph corresponding to the 1-skeleton of a 3D surface.
static int	getNumberOfNodes(java.lang.String filename) Get the number of nodes of a graph (stored as an edge list) Remark: we assume there is no header (no number of nodes stored)
static ArrayBasedGraph	readEdgeListGraphFromFile(java.lang.String filename) Load a graph from a file storing an edge list Remark: there is no header
static ArrayBasedGraph	readGraphFromFile(java.lang.String filename) Load a graph from a file storing an edge list Remark: the header (first line) contains the number of nodes and arcs
static ArrayBasedGraph	readMetisFile(java.lang.String filename) Load a graph from a file (in Metis format) Warning: to check whether edges should appear once or twice Remarks: -) vertex indices range from 1 to n (instead of 0..n-1) -) edges appear only once in the file
static void	writeGraphToFile(ArrayBasedGraph g, java.lang.String filename) Encode (the connectivity of) a given graph into a text file
static void	writeMeshSkeletonToFile(java.lang.String meshname, java.lang.String output) Construct the skeleton graph from a mesh and encode it into a file Warning: it works only for triangle meshes

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ArrayBasedGraphLoader

public ArrayBasedGraphLoader()

Method Detail

readGraphFromFile

public static ArrayBasedGraph readGraphFromFile(java.lang.String filename)

Load a graph from a file storing an edge list Remark: the header (first line) contains the number of nodes and arcs

Parameters:

filename - the input file encoding the graph

Returns:

the resulting graph (array based adjacency list representation)

readEdgeListGraphFromFile

public static ArrayBasedGraph readEdgeListGraphFromFile(java.lang.String filename)

Load a graph from a file storing an edge list Remark: there is no header

Parameters:

filename - the input file encoding the graph

Returns:

the resulting graph (array based adjacency list representation)

getNumberOfNodes

public static int getNumberOfNodes(java.lang.String filename)

Get the number of nodes of a graph (stored as an edge list) Remark: we assume there is no header (no number of nodes stored)

Parameters:

filename - the input file encoding the graph

Returns:

the number of nodes (1+ the maximum node index)

readMetisFile

public static ArrayBasedGraph readMetisFile(java.lang.String filename)

Load a graph from a file (in Metis format) Warning: to check whether edges should appear once or twice Remarks: -) vertex indices range from 1 to n (instead of 0..n-1) -) edges appear only once in the file

Parameters:

filename - the input file encoding the graph (lists of neighbors)

Returns:

the resulting graph (array based adjacency list representation)

writeGraphToFile

public static void writeGraphToFile(ArrayBasedGraph g,
                                    java.lang.String filename)

Encode (the connectivity of) a given graph into a text file

Parameters:

g - the graph to encode

filename - the output file

writeMeshSkeletonToFile

public static void writeMeshSkeletonToFile(java.lang.String meshname,
                                           java.lang.String output)

Construct the skeleton graph from a mesh and encode it into a file Warning: it works only for triangle meshes

Parameters:

meshname - the file storing the mesh

output - the output file (encoding the graph)

constructFromPolyhedron

public static ArrayBasedGraph constructFromPolyhedron(Polyhedron_3<Point_> polyhedron)

Construct the graph corresponding to the 1-skeleton of a 3D surface. Graph vertices are ordered according to the original vertex numbering (in the polyhedron)