Package edu.cmu.tetrad.util

Class PagCache

java.lang.Object

edu.cmu.tetrad.util.PagCache

public class PagCache
extends Object

A cache for storing PAGs so that the only need to be calculated once per DAG.

Method Summary

Modifier and Type	Method	Description
Graph	getDag(Graph graph)	Returns the Directed Acyclic Graph (DAG) corresponding to the given graph if it is a PAG that has previously been converted from a DAG.
static PagCache	getInstance()	Returns the singleton instance of the PagCache.
Graph	getPag(Graph graph)	Returns the PAG (Partial Ancestral Graph) corresponding to the given DAG (Directed Acyclic Graph).
Graph	getPag(Graph graph, Knowledge knowledge, boolean verbose)	Returns the PAG (Partial Ancestral Graph) corresponding to the given DAG (Directed Acyclic Graph).

Methods inherited from class java.lang.Object

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

Method Details

getInstance

public static PagCache getInstance()

Returns the singleton instance of the PagCache.

Returns:

the singleton instance of PagCache.

getPag

public Graph getPag(Graph graph)

Returns the PAG (Partial Ancestral Graph) corresponding to the given DAG (Directed Acyclic Graph). If the conversion has already been performed earlier, the cached result will be returned. Otherwise, the DAG will be converted to a PAG, cached, and then returned.

Parameters:

graph - the input DAG to be transformed into a PAG

Returns:

the corresponding PAG of the input DAG

Throws:

IllegalArgumentException - if the input graph is not a DAG

getPag

public Graph getPag(Graph graph,
 Knowledge knowledge,
 boolean verbose)

Returns the PAG (Partial Ancestral Graph) corresponding to the given DAG (Directed Acyclic Graph). If the conversion has already been performed earlier, the cached result will be returned. Otherwise, the DAG will be converted to a PAG, cached, and then returned.

Parameters:

graph - the input DAG to be transformed into a PAG

knowledge - the knowledge that should be used for the conversion

verbose - whether to print verbose output

Returns:

the corresponding PAG of the input DAG

Throws:

IllegalArgumentException - if the input graph is not a DAG

getDag

public Graph getDag(Graph graph)

Returns the Directed Acyclic Graph (DAG) corresponding to the given graph if it is a PAG that has previously been converted from a DAG. Otherwise, if it is a DAG, the input graph is returned as is. Otherwise, null is returned.

Parameters:

graph - the input graph to be checked and potentially converted to a DAG

Returns:

the corresponding DAG if the input graph is a legal DAG or present in cache; null otherwise