Package com.bayesserver.causal

Class CausalInferenceBase

java.lang.Object

com.bayesserver.causal.CausalInferenceBase

All Implemented Interfaces:

Inference

Direct Known Subclasses:

BackdoorInference, DisjunctiveCauseInference, FrontDoorInference

public abstract class CausalInferenceBase
extends Object
implements Inference

Base class for Causal inference engines used by internal algorithms.

Constructor Summary

Constructors

Constructor	Description
CausalInferenceBase(Network network, InferenceFactory factory)	Initializes a new instance of the CausalInferenceBase class.

Method Summary

Modifier and Type	Method	Description
Evidence	getBaseEvidence()	Optional evidence which can be used to calculate the lift of queries.
Evidence	getEvidence()	Represents the evidence, or case data (e.g.
Network	getNetwork()	The target Bayesian network.
QueryDistributionCollection	getQueryDistributions()	Gets the collection of distributions to calculate.
QueryFunctionCollection	getQueryFunctions()	Gets the collection of functions to evaluate, after QueryDistributions have been calculated.
QueryLifecycle	getQueryLifecycle()	Optional, allowing callers to hook into query lifecycle events, such as begin query and end query.
void	query(QueryOptions queryOptions, QueryOutput queryOutput)	Calculates a number of distributions, e.g.
protected abstract void	queryDistributionsInner(QueryOptions queryOptions, QueryOutput queryOutput)
void	setBaseEvidence(Evidence value)	Optional evidence which can be used to calculate the lift of queries.
void	setEvidence(Evidence value)	Represents the evidence, or case data (e.g.
protected void	setNetwork(Network value)
void	setQueryDistributions(QueryDistributionCollection value)	Sets the collection of distributions to calculate.
void	setQueryFunctions(QueryFunctionCollection value)	Sets the collection of functions to evaluate, after QueryDistributions have been calculated.
void	setQueryLifecycle(QueryLifecycle value)	Optional, allowing callers to hook into query lifecycle events, such as begin query and end query.

Methods inherited from class java.lang.Object

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

Constructor Detail

CausalInferenceBase

public CausalInferenceBase(Network network,
                           InferenceFactory factory)

Initializes a new instance of the CausalInferenceBase class.

Parameters:

network - The Bayesian network.

factory - Inference factory which is used when a network transformation is required.

Method Detail

query

public void query(QueryOptions queryOptions,
                  QueryOutput queryOutput)
           throws InconsistentEvidenceException

Calculates a number of distributions, e.g. P(A) and P(B) given the evidence (case data, e.g. row in a database), and if requested the log-likelihood of the data. Each time this method is called the distributions have their values replaced, acting like buffers.

As well as requesting distributions of the form P(A), P(B) it is also possible to request distributions over a number of variables such as P(A,B).

If CLGaussian distributions are requested that include instantiated discrete variables, an algorithm may legitimately return mean and covariance values equal to NaN for entries corresponding to inconsistent discrete combinations. For example, if a CLGaussian is requested that includes a discrete variable 'Gender' with states 'Male' and 'Female' and evidence is set to 'Female' then any mean and covariance entries that correspond to 'Male' may be set to NaN. NaN values will always be accompanied by a corresponding zero value in the CLGaussian.getTable().

Specified by:

query in interface Inference

Parameters:

queryOptions - Options governing which calculations are performed and how.

queryOutput - Returns any information, in addition to the distributions, that is requested. For example the log-likelihood.

Throws:

InconsistentEvidenceException - Raised if inconsistent evidence is detected, or underflow/overflow occurs when calculating queries or the conflict measure. Note that log-likelihood calculations do not raise this exception, but instead report -Infinity or +Infinity.

queryDistributionsInner

protected abstract void queryDistributionsInner(QueryOptions queryOptions,
                                                QueryOutput queryOutput)
                                         throws InconsistentEvidenceException

Throws:

InconsistentEvidenceException

getNetwork

public Network getNetwork()

The target Bayesian network.

Specified by:

getNetwork in interface Inference

setNetwork

protected void setNetwork(Network value)

getEvidence

public Evidence getEvidence()

Represents the evidence, or case data (e.g. row in a database) used in a query. The distributions are only recalculated by Inference.query(com.bayesserver.inference.QueryOptions, com.bayesserver.inference.QueryOutput), not each time evidence is changed.

For more information see Evidence.

Specified by:

getEvidence in interface Inference

setEvidence

public void setEvidence(Evidence value)

Represents the evidence, or case data (e.g. row in a database) used in a query. The distributions are only recalculated by Inference.query(com.bayesserver.inference.QueryOptions, com.bayesserver.inference.QueryOutput), not each time evidence is changed.

For more information see Evidence.

Specified by:

setEvidence in interface Inference

getBaseEvidence

public Evidence getBaseEvidence()

Optional evidence which can be used to calculate the lift of queries. Defaults to null. When QueryDistribution.getComparison() is true queries are adjusted based on marginals calculated with this evidence or no evidence if this value is null.

Specified by:

getBaseEvidence in interface Inference

See Also:

QueryDistribution.getComparison()

setBaseEvidence

public void setBaseEvidence(Evidence value)

Optional evidence which can be used to calculate the lift of queries. Defaults to null. When QueryDistribution.getComparison() is true queries are adjusted based on marginals calculated with this evidence or no evidence if this value is null.

Specified by:

setBaseEvidence in interface Inference

See Also:

QueryDistribution.getComparison()

getQueryDistributions

public QueryDistributionCollection getQueryDistributions()

Gets the collection of distributions to calculate. See QueryDistributionCollection. If required, a query distribution collection can be dynamically attached or detached. Also note that individual elements can be enabled or disabled on a per query basis.

Specified by:

getQueryDistributions in interface Inference

setQueryDistributions

public void setQueryDistributions(QueryDistributionCollection value)

Sets the collection of distributions to calculate. See QueryDistributionCollection. If required, a query distribution collection can be dynamically attached or detached. Also note that individual elements can be enabled or disabled on a per query basis.

Specified by:

setQueryDistributions in interface Inference

getQueryLifecycle

public QueryLifecycle getQueryLifecycle()

Optional, allowing callers to hook into query lifecycle events, such as begin query and end query.

Specified by:

getQueryLifecycle in interface Inference

setQueryLifecycle

public void setQueryLifecycle(QueryLifecycle value)

Optional, allowing callers to hook into query lifecycle events, such as begin query and end query.

Specified by:

setQueryLifecycle in interface Inference

getQueryFunctions

public QueryFunctionCollection getQueryFunctions()

Gets the collection of functions to evaluate, after QueryDistributions have been calculated. If required, a query function collection can be dynamically attached or detached. Also note that individual elements can be enabled or disabled on a per query basis.

Specified by:

getQueryFunctions in interface Inference

setQueryFunctions

public void setQueryFunctions(QueryFunctionCollection value)

Sets the collection of functions to evaluate, after QueryDistributions have been calculated. If required, a query function collection can be dynamically attached or detached. Also note that individual elements can be enabled or disabled on a per query basis.

Specified by:

setQueryFunctions in interface Inference