org.apache.spark.ml.feature

Class IndexToString

Object

org.apache.spark.ml.PipelineStage

org.apache.spark.ml.Transformer

org.apache.spark.ml.feature.IndexToString

All Implemented Interfaces:

java.io.Serializable, org.apache.spark.internal.Logging, Params, HasInputCol, HasOutputCol, DefaultParamsWritable, Identifiable, MLWritable

public class IndexToString
extends Transformer
implements HasInputCol, HasOutputCol, DefaultParamsWritable

A Transformer that maps a column of indices back to a new column of corresponding string values. The index-string mapping is either from the ML attributes of the input column, or from user-supplied labels (which take precedence over ML attributes).

See Also:

StringIndexer for converting strings into indices, Serialized Form

Constructor Summary

Constructors

Constructor and Description
IndexToString()
IndexToString(String uid)

Method Summary

Modifier and Type	Method and Description
IndexToString	copy(ParamMap extra) Creates a copy of this instance with the same UID and some extra params.
String[]	getLabels()
Param<String>	inputCol() Param for input column name.
StringArrayParam	labels() Optional param for array of labels specifying index-string mapping.
static IndexToString	load(String path)
Param<String>	outputCol() Param for output column name.
static MLReader<T>	read()
IndexToString	setInputCol(String value)
IndexToString	setLabels(String[] value)
IndexToString	setOutputCol(String value)
Dataset<Row>	transform(Dataset<?> dataset) Transforms the input dataset.
StructType	transformSchema(StructType schema) Check transform validity and derive the output schema from the input schema.
String	uid() An immutable unique ID for the object and its derivatives.

Methods inherited from class org.apache.spark.ml.Transformer

transform, transform, transform

Methods inherited from class org.apache.spark.ml.PipelineStage

params

Methods inherited from class Object

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

Methods inherited from interface org.apache.spark.ml.param.shared.HasInputCol

getInputCol

Methods inherited from interface org.apache.spark.ml.param.shared.HasOutputCol

getOutputCol

Methods inherited from interface org.apache.spark.ml.param.Params

clear, copyValues, defaultCopy, defaultParamMap, explainParam, explainParams, extractParamMap, extractParamMap, get, getDefault, getOrDefault, getParam, hasDefault, hasParam, isDefined, isSet, paramMap, params, set, set, set, setDefault, setDefault, shouldOwn

Methods inherited from interface org.apache.spark.ml.util.Identifiable

toString

Methods inherited from interface org.apache.spark.ml.util.DefaultParamsWritable

write

Methods inherited from interface org.apache.spark.ml.util.MLWritable

save

Methods inherited from interface org.apache.spark.internal.Logging

$init$, initializeForcefully, initializeLogIfNecessary, initializeLogIfNecessary, initializeLogIfNecessary$default$2, initLock, isTraceEnabled, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning, org$apache$spark$internal$Logging$$log__$eq, org$apache$spark$internal$Logging$$log_, uninitialize

Constructor Detail

IndexToString

public IndexToString(String uid)

IndexToString

public IndexToString()

Method Detail

load

public static IndexToString load(String path)

read

public static MLReader<T> read()

outputCol

public final Param<String> outputCol()

Description copied from interface: HasOutputCol

Param for output column name.

Specified by:

outputCol in interface HasOutputCol

Returns:

(undocumented)

inputCol

public final Param<String> inputCol()

Description copied from interface: HasInputCol

Param for input column name.

Specified by:

inputCol in interface HasInputCol

Returns:

(undocumented)

uid

public String uid()

Description copied from interface: Identifiable

An immutable unique ID for the object and its derivatives.

Specified by:

uid in interface Identifiable

Returns:

(undocumented)

setInputCol

public IndexToString setInputCol(String value)

setOutputCol

public IndexToString setOutputCol(String value)

setLabels

public IndexToString setLabels(String[] value)

labels

public final StringArrayParam labels()

Optional param for array of labels specifying index-string mapping.

Default: Not specified, in which case inputCol metadata is used for labels.

Returns:

(undocumented)

getLabels

public final String[] getLabels()

transformSchema

public StructType transformSchema(StructType schema)

Description copied from class: PipelineStage

Check transform validity and derive the output schema from the input schema.

We check validity for interactions between parameters during transformSchema and raise an exception if any parameter value is invalid. Parameter value checks which do not depend on other parameters are handled by Param.validate().

Typical implementation should first conduct verification on schema change and parameter validity, including complex parameter interaction checks.

Specified by:

transformSchema in class PipelineStage

Parameters:

schema - (undocumented)

Returns:

(undocumented)

transform

public Dataset<Row> transform(Dataset<?> dataset)

Description copied from class: Transformer

Transforms the input dataset.

Specified by:

transform in class Transformer

Parameters:

dataset - (undocumented)

Returns:

(undocumented)

copy

public IndexToString copy(ParamMap extra)

Description copied from interface: Params

Creates a copy of this instance with the same UID and some extra params. Subclasses should implement this method and set the return type properly. See defaultCopy().

Specified by:

copy in interface Params

Specified by:

copy in class Transformer

Parameters:

extra - (undocumented)

Returns:

(undocumented)