com.pervasive.datarush.analytics.text

Class ExpandTextFrequency

java.lang.Object

com.pervasive.datarush.operators.AbstractLogicalOperator

com.pervasive.datarush.operators.StreamingOperator

com.pervasive.datarush.operators.ExecutableOperator

com.pervasive.datarush.analytics.text.ExpandTextFrequency

All Implemented Interfaces:

LogicalOperator, PipelineOperator<RecordPort>, RecordPipelineOperator

public class ExpandTextFrequency
extends ExecutableOperator
implements RecordPipelineOperator

Expands text frequency field. This operator can be used to expand the output from one of the text frequency calculators. The operator requires specifying a frequency map field which can contain a WordMap or an NGramMap. It will output a field containing the expanded text and a field containing the associated frequencies. If either output fields are not specified then the field will not be included in the output. This will additionally cause an expansion of the original data since any field that is not actively expanded will simply be copied. The operator can also specify whether the absolute or relative frequencies will be output in the frequency output field.

Constructor Summary

Constructors

Constructor and Description
ExpandTextFrequency() Default constructor.
ExpandTextFrequency(String inputField) Constructor specifying the input field containing the frequency map.

Method Summary

Modifier and Type	Method and Description
protected void	computeMetadata(StreamingMetadataContext ctx) Implementations must adhere to the following contracts
protected void	execute(ExecutionContext ctx) Executes the operator.
String	getFreqOutputField() Get the output field to expand the frequency list into.
RecordPort	getInput() Get the input port of this operator.
String	getInputField() Get the frequency map field to expand.
RecordPort	getOutput() Get the output port of this operator.
boolean	getRelative() Get whether absolute or relative frequencies will be expanded.
String	getTextOutputField() Get the output field to expand the text list into.
void	setFreqOutputField(String freqOutputField) Set the output field to expand the frequency list into.
void	setInputField(String inputField) Set the frequency map field to expand.
void	setRelative(boolean relative) Set whether absolute or relative frequencies will be expanded.
void	setTextOutputField(String textOutputField) Set the output field to expand the text list into.

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

cloneForExecution, getNumInputCopies, getPortSettings, handleInactiveOutput

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

ExpandTextFrequency

public ExpandTextFrequency()

Default constructor. Use setInputField(String) to set the names of the frequency map input field.

ExpandTextFrequency

public ExpandTextFrequency(String inputField)

Constructor specifying the input field containing the frequency map.

Parameters:

inputField - name of the text field to expand

Method Detail

setInputField

public void setInputField(String inputField)

Set the frequency map field to expand. The field should be a Wordmap or an NGramMap

If this field does not exist in the input, or is not of type WordMap or NGramMap, an exception will be thrown at composition time.

Parameters:

inputField - name of the text field to expand

getInputField

public String getInputField()

Get the frequency map field to expand.

Returns:

The name of the frequency map field to expand

setTextOutputField

public void setTextOutputField(String textOutputField)

Set the output field to expand the text list into. If unspecified will not output this field.

Parameters:

textOutputField - name of the string output field

getTextOutputField

public String getTextOutputField()

Get the output field to expand the text list into.

Returns:

The name of the string output field

setFreqOutputField

public void setFreqOutputField(String freqOutputField)

Set the output field to expand the frequency list into. If unspecified will not output this field.

Parameters:

freqOutputField - name of the double output field

getFreqOutputField

public String getFreqOutputField()

Get the output field to expand the frequency list into.

Returns:

The name of the double output field

setRelative

public void setRelative(boolean relative)

Set whether absolute or relative frequencies will be expanded. Defaults to false for absolute frequencies.

Parameters:

relative - true if relative frequencies will be output

getRelative

public boolean getRelative()

Get whether absolute or relative frequencies will be expanded.

Returns:

true if relative frequencies will be output

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

computeMetadata

protected void computeMetadata(StreamingMetadataContext ctx)

Description copied from class: StreamingOperator

Implementations must adhere to the following contracts

General

Regardless of input ports/output port types, all implementations must do the following:

1. Validation. Validation of configuration should always be performed first.
2. Declare parallelizability.. Implementations must declare parallelizability by calling StreamingMetadataContext.parallelize(ParallelismStrategy).

Input record ports

Implementations with input record ports must declare the following:

1. Required data ordering:
Implementations that have data ordering requirements must declare them by calling RecordPort#setRequiredDataOrdering, otherwise data may arrive in any order.
2. Required data distribution (only applies to parallelizable operators):
Implementations that have data distribution requirements must declare them by calling RecordPort#setRequiredDataDistribution, otherwise data will arrive in an unspecified partial distribution.

Note that if the upstream operator's output distribution/ordering is compatible with those required, we avoid a re-sort/re-distribution which is generally a very large savings from a performance standpoint. In addition, some operators may chose to query the upstream output distribution/ordering by calling RecordPort#getSourceDataDistribution and RecordPort#getSourceDataOrdering. These should be viewed as a hints to help chose a more efficient algorithm. In such cases, though, operators must still declare data ordering and data distribution requirements; otherwise there is no guarantee that data will arrive sorted/distributed as required.

Output record ports

Implementations with output record ports must declare the following:

1. Type: Implementations must declare their output type by calling RecordPort#setType.

Implementations with output record ports may declare the following:

1. Output data ordering: Implementations that can make guarantees as to their output ordering may do so by calling RecordPort#setOutputDataOrdering
2. Output data distribution (only applies to parallelizable operators): Implementations that can make guarantees as to their output distribution may do so by calling RecordPort#setOutputDataDistribution

Note that both of these properties are optional; if unspecified, performance may suffer since the framework may unnecessarily re-sort/re-distributed the data.

Input model ports

In general, there is nothing special to declare for input model ports. Models are implicitly duplicated to all partitions when going from non-parallel to parallel operators. The case of a model going from a parallel to a non-parallel node is a special case of a "model reducer" operator. In the case of a model reducer, the downstream operator, must declare the following:

1. Merge handler: Model reducers must declare a merge handler by calling AbstractModelPort#setMergeHandler.

Note that MergeModel is a convenient, re-usable model reducer, parameterized with a merge-handler.

Output model ports

SimpleModelPort's have no associated metadata and therefore there is never any output metadata to declare. PMMLPort's, on the other hand, do have associated metadata. For all PMMLPorts, implementations must declare the following:

1. pmmlModelSpec: Implementations must declare the PMML model spec by calling PMMLPort.setPMMLModelSpec.

Specified by:

computeMetadata in class StreamingOperator

Parameters:

ctx - the context

execute

protected void execute(ExecutionContext ctx)

Description copied from class: ExecutableOperator

Executes the operator. Implementations should adhere to the following contracts:

1. Following execution, all input ports must be at end-of-data.
2. Following execution, all output ports must be at end-of-data.

Specified by:

execute in class ExecutableOperator

Parameters:

ctx - context in which to lookup physical ports bound to logical ports