Cytoscape 2.8.0 API

cytoscape.graph.fixed
Interface FixedGraph

All Known Subinterfaces:
DynamicGraph
All Known Implementing Classes:
CytoscapeFingRootGraph, FingCyNetwork, FingExtensibleGraphPerspective, FingExtensibleRootGraph

public interface FixedGraph

A graph topology. Edges and nodes are non-negative integers; a given node and a given edge in a single graph can be the same integer.


Field Summary
static byte DIRECTED_EDGE
          A nonnegative quantity representing directedness of an edge.
static byte UNDIRECTED_EDGE
          A nonnegative quantity representing undirectedness of an edge.
 
Method Summary
 IntEnumerator edges()
          Returns an enumeration of all edges in this graph.
 IntEnumerator edgesAdjacent(int node, boolean outgoing, boolean incoming, boolean undirected)
          Returns a non-repeating enumeration of edges adjacent to a node.
 IntIterator edgesConnecting(int node0, int node1, boolean outgoing, boolean incoming, boolean undirected)
          Returns a non-repeating iteration of edges connecting two nodes.
 int edgeSource(int edge)
          Determines the source node of an edge.
 int edgeTarget(int edge)
          Determines the target node of an edge.
 byte edgeType(int edge)
          Determines the existence and directedness of an edge.
 boolean nodeExists(int node)
          Determines whether or not a node exists in this graph.
 IntEnumerator nodes()
          Returns an enumeration of all nodes in this graph.
 

Field Detail

DIRECTED_EDGE

static final byte DIRECTED_EDGE
A nonnegative quantity representing directedness of an edge.

See Also:
Constant Field Values

UNDIRECTED_EDGE

static final byte UNDIRECTED_EDGE
A nonnegative quantity representing undirectedness of an edge.

See Also:
Constant Field Values
Method Detail

nodes

IntEnumerator nodes()
Returns an enumeration of all nodes in this graph. Every node in this graph is a unique non-negative integer. A given node and a given edge in one graph may be the same integer.

Returns:
an enumeration over all nodes in this graph; null is never returned.

edges

IntEnumerator edges()
Returns an enumeration of all edges in this graph. Every edge in this graph is a unique non-negative integer. A given node and a given edge in one graph may be the same integer.

Returns:
an enumeration over all edges in this graph; null is never returned.

nodeExists

boolean nodeExists(int node)
Determines whether or not a node exists in this graph. Returns true if and only if the node specified exists.

Note that this method is superfluous in this interface (that is, it could be removed without losing any functionality), because edgesAdjacent(int, boolean, boolean, boolean) can be used to test the presence of a node. However, because nodeExists(int) does not return a complicated object, its performance may be better than that of edgesAdjacent().

Parameters:
node - the [potentially existing] node in this graph whose existence we're querying.
Returns:
the existence of specified node in this graph.

edgeType

byte edgeType(int edge)
Determines the existence and directedness of an edge. Returns -1 if specified edge does not exist in this graph, otherwise returns DIRECTED_EDGE or UNDIRECTED_EDGE.

Parameters:
edge - the edge in this graph whose existence and/or directedness we're seeking.
Returns:
DIRECTED_EDGE if specified edge is directed, UNDIRECTED_EDGE if specified edge is undirected, and -1 if specified edge does not exist in this graph.

edgeSource

int edgeSource(int edge)
Determines the source node of an edge. Returns the source node of specified edge or -1 if specified edge does not exist in this graph.

Parameters:
edge - the edge in this graph whose source node we're seeking.
Returns:
the source node of specified edge or -1 if specified edge does not exist in this graph.

edgeTarget

int edgeTarget(int edge)
Determines the target node of an edge. Returns the target node of specified edge or -1 if specified edge does not exist in this graph.

Parameters:
edge - the edge in this graph whose target node we're seeking.
Returns:
the target node of specified edge or -1 if specified edge does not exist in this graph.

edgesAdjacent

IntEnumerator edgesAdjacent(int node,
                            boolean outgoing,
                            boolean incoming,
                            boolean undirected)
Returns a non-repeating enumeration of edges adjacent to a node. The three boolean input parameters define what is meant by "adjacent edge". If all three boolean input parameters are false, the returned enumeration will have zero elements.

This method returns null if and only if the specified node does not exist in this graph. Therefore, this method can be used to test the existence of a node in this graph.

Parameters:
node - the node in this graph whose adjacent edges we're seeking.
outgoing - all directed edges whose source is the node specified are included in the returned enumeration if this value is true; otherwise, not a single such edge is included in the returned enumeration.
incoming - all directed edges whose target is the node specified are included in the returned enumeration if this value is true; otherwise, not a single such edge is included in the returned enumeration.
undirected - all undirected edges touching the specified node are included in the returned enumeration if this value is true; otherwise, not a single such edge is included in the returned enumeration.
Returns:
an enumeration of edges adjacent to the node specified or null if specified node does not exist in this graph.

edgesConnecting

IntIterator edgesConnecting(int node0,
                            int node1,
                            boolean outgoing,
                            boolean incoming,
                            boolean undirected)
Returns a non-repeating iteration of edges connecting two nodes. The three boolean input parameters define what is meant by "connecting edge". If all three boolean input parameters are false, the returned iteration will have no elements.

I'd like to discuss the motivation behind this interface method. I assume that most implementations of this interface will implement this method in terms of edgesAdjacent(). Why, then, is this method necessary? Because some implementations may choose to optimize the implementation of this method by using a search tree or a hashtable, for example. This method is a hook to provide such optimization.

This method returns an IntIterator as opposed to an IntEnumerator so that non-optimized implementations would not be required to pre-compute the number of edges being returned.

Parameters:
node0 - one of the nodes in this graph whose connecting edges we're seeking.
node1 - one of the nodes in this graph whose connecting edges we're seeking.
outgoing - all directed edges whose source is node0 and whose target is node1 are included in the returned iteration if this value is true; otherwise, not a single such edge is included in the returned iteration.
incoming - all directed edges whose source is node1 and whose target is node0 are included in the returned iteration if this value is true; otherwise, not a single such edge is included in the returned iteration.
undirected - all undirected edges E such that E's endpoints are node0 and node1 are included in the returned iteration if this value is true; otherwise, not a single such edge is incuded in the returned iteration.
Returns:
an iteration of edges connecting node0 with node1 in a fashion specified by boolean input parameters or null if either of node0 or node1 does not exist in this graph.

Cytoscape 2.8.0 API

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