Module datarush.analytics

Package com.pervasive.datarush.analytics.arm

Class FrequentItems

java.lang.Object

com.pervasive.datarush.operators.AbstractLogicalOperator

com.pervasive.datarush.operators.CompositeOperator

com.pervasive.datarush.analytics.arm.FrequentItems

All Implemented Interfaces:

LogicalOperator, PipelineOperator<RecordPort>, RecordPipelineOperator

public class FrequentItems
extends CompositeOperator
implements RecordPipelineOperator

Compute the frequent items within the given transactions. Two fields are needed in the input flow: one to identify transactions and another to identify items. A minimum support value must be specified as a percentage of transactions an item must participate in to be considered frequent. An optional label field may also be specified which will be used for display purposes instead of the transaction identifiers.

The main output of this operator is the set of frequent items. Two fields are output, the item field from the input and the frequency count of the item.

The operator also outputs a PMML port that contains an association model. The model will be partially filled in with frequent items and transaction statistics.

Constructor Summary

Constructors

Constructor	Description
FrequentItems()	Default constructor.
FrequentItems(String txnFieldName, String itemFieldName, double minSupport)	Construct with properties.

Method Summary

Modifier and Type	Method	Description
protected void	compose(CompositionContext ctx)	Compose the body of this operator.
RecordPort	getInput()	Get the input port of this operator.
String	getItemFieldName()	Get the item field name property.
String	getLabelFieldName()	Get the optional label field name property.
double	getMinSupport()	Get the minimum support property.
PMMLPort	getModel()	Get the output PMML model port of this plan operator.
RecordPort	getOutput()	Get the output port of this operator.
String	getTxnFieldName()	Get the transaction field name property.
void	setItemFieldName(String itemFieldName)	Set the item field name property.
void	setLabelFieldName(String labelFieldName)	Set the optional label field name property.
void	setMinSupport(double minSupport)	Set the minimum support property.
void	setTxnFieldName(String txnFieldName)	Set the transaction field name property.

Methods inherited from class com.pervasive.datarush.operators.AbstractLogicalOperator

disableParallelism, getInputPorts, getOutputPorts, newInput, newInput, newOutput, newRecordInput, newRecordInput, newRecordOutput, notifyError

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.pervasive.datarush.operators.LogicalOperator

disableParallelism, getInputPorts, getOutputPorts

Constructor Detail

FrequentItems

public FrequentItems()

Default constructor.

FrequentItems

public FrequentItems(String txnFieldName,
                     String itemFieldName,
                     double minSupport)

Construct with properties.

Parameters:

txnFieldName - name of the field containing the transaction identifier

itemFieldName - name of the field containing the item name

minSupport - minimum support percentage (must be between 0 and 1)

Method Detail

getInput

public RecordPort getInput()

Get the input port of this operator.

Specified by:

getInput in interface PipelineOperator<RecordPort>

Returns:

input port

getOutput

public RecordPort getOutput()

Get the output port of this operator.

Specified by:

getOutput in interface PipelineOperator<RecordPort>

Returns:

output port

getModel

public PMMLPort getModel()

Get the output PMML model port of this plan operator. The PMML uses the association rules model format. Only some transaction statistics and the frequent items are captured in the model. A rule mining algorithm can add the item sets and association rules.

Returns:

PMML model capturing frequent items

getTxnFieldName

public String getTxnFieldName()

Get the transaction field name property.

Returns:

transaction field name

setTxnFieldName

public void setTxnFieldName(String txnFieldName)

Set the transaction field name property.

Parameters:

txnFieldName - transaction field name

getItemFieldName

public String getItemFieldName()

Get the item field name property.

Returns:

item field name

setItemFieldName

public void setItemFieldName(String itemFieldName)

Set the item field name property.

Parameters:

itemFieldName - item field name

getMinSupport

public double getMinSupport()

Get the minimum support property.

Returns:

minimum support percentage

setMinSupport

public void setMinSupport(double minSupport)

Set the minimum support property.

Parameters:

minSupport - minimum support percentage

getLabelFieldName

public String getLabelFieldName()

Get the optional label field name property.

Returns:

label field name

setLabelFieldName

public void setLabelFieldName(String labelFieldName)

Set the optional label field name property.

Parameters:

labelFieldName - label field name

compose

protected void compose(CompositionContext ctx)

Description copied from class: CompositeOperator

Compose the body of this operator. Implementations should do the following:

1. Perform any validation of configuration, input types, etc
2. Instantiate and configure sub-operators, adding them to the provided context via the method OperatorComposable.add(O)
3. Create necessary connections via the method OperatorComposable.connect(P, P). This includes connections from the composite's input ports to sub-operators, connections between sub-operators, and connections from sub-operators output ports to the composite's output ports

Specified by:

compose in class CompositeOperator

Parameters:

ctx - the context