Package edu.cmu.tetrad.search

Class DagInCPDAGIterator

java.lang.Object

edu.cmu.tetrad.search.DagInCPDAGIterator

public class DagInCPDAGIterator
extends Object

Given a pattern, lists all of the DAGs in that pattern. In the form of an iterator--call hasNext() to see if there's another one and next() to get it. next() will return null if there are no more.

Author:

Joseph Ramsey

Constructor Summary

Constructors

Constructor	Description
DagInCPDAGIterator(Graph CPDAG)
DagInCPDAGIterator(Graph CPDAG, Knowledge knowledge)
DagInCPDAGIterator(Graph CPDAG, Knowledge knowledge, boolean allowArbitraryOrientations, boolean allowNewColliders)	The given CPDAG must be a CPDAG.

Method Summary

Modifier and Type	Method	Description
Knowledge	getKnowledge()
boolean	hasNext()
Graph	next()	Successive calls to this method return successive DAGs in the CPDAG, in a more or less natural enumeration of them in which an arbitrary undirected edge is picked, oriented one way, Meek rules applied, then a remaining unoriented edge is picked, oriented one way, and so on, until a DAG is obtained, and then by backtracking the other orientation of each chosen edge is tried.

Methods inherited from class java.lang.Object

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

Constructor Details

DagInCPDAGIterator

public DagInCPDAGIterator(Graph CPDAG)

DagInCPDAGIterator

public DagInCPDAGIterator(Graph CPDAG,
 Knowledge knowledge)

DagInCPDAGIterator

public DagInCPDAGIterator(Graph CPDAG,
 Knowledge knowledge,
 boolean allowArbitraryOrientations,
 boolean allowNewColliders)

The given CPDAG must be a CPDAG. If it does not consist entirely of directed and undirected edges and if it is not acyclic, it is rejected.

Parameters:

CPDAG - The CPDAG for which DAGS are wanted.

allowArbitraryOrientations - True if arbitrary orientations are allowable when reasonable ones cannot be made. May result in cyclic outputs.

Throws:

IllegalArgumentException - if the CPDAG is not a CPDAG.

Method Details

next

public Graph next()

Successive calls to this method return successive DAGs in the CPDAG, in a more or less natural enumeration of them in which an arbitrary undirected edge is picked, oriented one way, Meek rules applied, then a remaining unoriented edge is picked, oriented one way, and so on, until a DAG is obtained, and then by backtracking the other orientation of each chosen edge is tried. Nonrecursive, obviously.

Returns:

a Graph instead of a DAG because sometimes, due to faulty CPDAGs, a cyclic graph is produced, and the end-user may need to decide what to do with it. The simplest thing is to construct a DAG (Dag(graph)) and catch an exception.

hasNext

public boolean hasNext()

Returns:

true just in case there is still a DAG remaining in the enumeration of DAGs for this CPDAG.

getKnowledge

public Knowledge getKnowledge()