Package org.apache.spark.ml.feature

Class StringIndexerAggregator

Object

org.apache.spark.sql.expressions.Aggregator<Row,org.apache.spark.util.collection.OpenHashMap<String,Object>[],org.apache.spark.util.collection.OpenHashMap<String,Object>[]>

org.apache.spark.ml.feature.StringIndexerAggregator

All Implemented Interfaces:

Serializable

public class StringIndexerAggregator
extends Aggregator<Row,org.apache.spark.util.collection.OpenHashMap<String,Object>[],org.apache.spark.util.collection.OpenHashMap<String,Object>[]>

A SQL Aggregator used by StringIndexer to count labels in string columns during fitting.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
StringIndexerAggregator(int numColumns)

Method Summary

Modifier and Type	Method	Description
Encoder<org.apache.spark.util.collection.OpenHashMap<String,Object>[]>	bufferEncoder()	Specifies the Encoder for the intermediate value type.
org.apache.spark.util.collection.OpenHashMap<String,Object>[]	finish(org.apache.spark.util.collection.OpenHashMap<String,Object>[] array)	Transform the output of the reduction.
org.apache.spark.util.collection.OpenHashMap<String,Object>[]	merge(org.apache.spark.util.collection.OpenHashMap<String,Object>[] array1, org.apache.spark.util.collection.OpenHashMap<String,Object>[] array2)	Merge two intermediate values.
Encoder<org.apache.spark.util.collection.OpenHashMap<String,Object>[]>	outputEncoder()	Specifies the Encoder for the final output value type.
org.apache.spark.util.collection.OpenHashMap<String,Object>[]	reduce(org.apache.spark.util.collection.OpenHashMap<String,Object>[] array, Row row)	Combine two values to produce a new value.
org.apache.spark.util.collection.OpenHashMap<String,Object>[]	zero()	A zero value for this aggregation.

Methods inherited from class org.apache.spark.sql.expressions.Aggregator

toColumn

Methods inherited from class java.lang.Object

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

Constructor Details

StringIndexerAggregator

public StringIndexerAggregator(int numColumns)

Method Details

bufferEncoder

public Encoder<org.apache.spark.util.collection.OpenHashMap<String,Object>[]> bufferEncoder()

Description copied from class: Aggregator

Specifies the Encoder for the intermediate value type.

Specified by:

bufferEncoder in class Aggregator<Row,org.apache.spark.util.collection.OpenHashMap<String,Object>[],org.apache.spark.util.collection.OpenHashMap<String,Object>[]>

Returns:

(undocumented)

finish

public org.apache.spark.util.collection.OpenHashMap<String,Object>[] finish(org.apache.spark.util.collection.OpenHashMap<String,Object>[] array)

Description copied from class: Aggregator

Transform the output of the reduction.

Specified by:

finish in class Aggregator<Row,org.apache.spark.util.collection.OpenHashMap<String,Object>[],org.apache.spark.util.collection.OpenHashMap<String,Object>[]>

Parameters:

array - (undocumented)

Returns:

(undocumented)

merge

public org.apache.spark.util.collection.OpenHashMap<String,Object>[] merge(org.apache.spark.util.collection.OpenHashMap<String,Object>[] array1,
 org.apache.spark.util.collection.OpenHashMap<String,Object>[] array2)

Description copied from class: Aggregator

Merge two intermediate values.

Specified by:

merge in class Aggregator<Row,org.apache.spark.util.collection.OpenHashMap<String,Object>[],org.apache.spark.util.collection.OpenHashMap<String,Object>[]>

Parameters:

array1 - (undocumented)

array2 - (undocumented)

Returns:

(undocumented)

outputEncoder

public Encoder<org.apache.spark.util.collection.OpenHashMap<String,Object>[]> outputEncoder()

Description copied from class: Aggregator

Specifies the Encoder for the final output value type.

Specified by:

outputEncoder in class Aggregator<Row,org.apache.spark.util.collection.OpenHashMap<String,Object>[],org.apache.spark.util.collection.OpenHashMap<String,Object>[]>

Returns:

(undocumented)

reduce

public org.apache.spark.util.collection.OpenHashMap<String,Object>[] reduce(org.apache.spark.util.collection.OpenHashMap<String,Object>[] array,
 Row row)

Description copied from class: Aggregator

Combine two values to produce a new value. For performance, the function may modify b and return it instead of constructing new object for b.

Specified by:

reduce in class Aggregator<Row,org.apache.spark.util.collection.OpenHashMap<String,Object>[],org.apache.spark.util.collection.OpenHashMap<String,Object>[]>

Parameters:

array - (undocumented)

row - (undocumented)

Returns:

(undocumented)

zero

public org.apache.spark.util.collection.OpenHashMap<String,Object>[] zero()

Description copied from class: Aggregator

A zero value for this aggregation. Should satisfy the property that any b + zero = b.

Specified by:

zero in class Aggregator<Row,org.apache.spark.util.collection.OpenHashMap<String,Object>[],org.apache.spark.util.collection.OpenHashMap<String,Object>[]>

Returns:

(undocumented)