gum::Arc Class Reference

The base class for all directed edgesThis class is used as a basis for manipulating all directed edges (i.e., edges in which the order of the nodes is meaningful). More...

#include <graphElements.h>

Public Member Functions
Constructors / Destructors
	Arc (NodeId tail, NodeId head)
	basic constructor. Creates tail -> head. More...
	Arc (const Arc &src)
	copy constructor More...
	~Arc ()
	destructor More...
Accessors
NodeId	tail () const
	returns the tail of the arc More...
NodeId	head () const
	returns the head of the arc More...
NodeId	other (NodeId id) const
	returns an extremal node of an edge given the ID of the other one More...
NodeId	first () const
	returns one extremal node ID (whichever one it is is unspecified) More...
NodeId	second () const
	returns the node ID of the other extremal node ID More...
Operators
Arc &	operator= (const Arc &src)
	copy operator More...
bool	operator== (const Arc &src) const
	checks whether two arcs are equal More...
bool	operator!= (const Arc &src) const
	check if two arcs are different More...

Detailed Description

The base class for all directed edges

This class is used as a basis for manipulating all directed edges (i.e., edges in which the order of the nodes is meaningful).

For instance, in an arrow, one node is near the head and the other one is farther, hence these nodes have different status and swapping the nodes results in reversing the direction of the arrow. Thus, the nodes in an arrow can be thought of as asymmetric and the arrow's graphical representation contains a pointed extremity so as to account for this asymmetry. In aGrUM, the latter is taken into account by Arc.

Usage example:

// creation of an arc (directed edge) from 3 to 4
Arc arc1 (3,4);
  *
// compare two arcs
if (Arc(3,4) != Arc(4,3)) cerr << "ok, this is asymmetric" << endl;

// get the extremities of the edge
cerr << arc1.tail() << " = 3 and " << arc1.head() << " = 4\n";
cerr << "arc1 = (3 -> " << edge1.other (3) << ")" << endl;

// display an arc in a console
cerr << arc1 << endl;

Definition at line 250 of file graphElements.h.

Constructor & Destructor Documentation

Arc() [1/2]

gum::Arc::Arc	(	NodeId	tail,
		NodeId	head
	)

basic constructor. Creates tail -> head.

Warning

the order in which the nodes are passed is important

Arc() [2/2]

gum::Arc::Arc

(

const Arc &

src

)

copy constructor

~Arc()

gum::Arc::~Arc

(

)

destructor

Member Function Documentation

_setHead_()

void gum::Arc::_setHead_ ( NodeId  id )

private

modifies the head of the arc

_setTail_()

void gum::Arc::_setTail_ ( NodeId  id )

private

modifies the tail of the arc

first()

NodeId gum::Arc::first

(

)

const

returns one extremal node ID (whichever one it is is unspecified)

head()

NodeId gum::Arc::head

(

)

const

returns the head of the arc

operator!=()

bool gum::Arc::operator!=

(

const Arc &

src

)

const

check if two arcs are different

Two arcs are considered different if they have different head and/or tail (by different we mean they have different ID).

operator-()

void gum::Arc::operator- ( )

private

reverses the direction of the arc

operator=()

Arc& gum::Arc::operator=

(

const Arc &

src

)

copy operator

operator==()

bool gum::Arc::operator==

(

const Arc &

src

)

const

checks whether two arcs are equal

Two arcs are considered equal if they have the same head and tail (by same we mean they have the same ID).

other()

NodeId gum::Arc::other

(

NodeId

id

)

const

returns an extremal node of an edge given the ID of the other one

second()

NodeId gum::Arc::second

(

)

const

returns the node ID of the other extremal node ID

tail()

NodeId gum::Arc::tail

(

)

const

returns the tail of the arc

Member Data Documentation

n1

NodeId gum::Arc::n1

private

the extremal nodes of the edge (their order is unimportant)

Definition at line 314 of file graphElements.h.

n2

NodeId gum::Arc::n2

private

Definition at line 314 of file graphElements.h.

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The documentation for this class was generated from the following file:

• agrum/tools/graphs/graphElements.h