org.apache.spark.ml.feature

Class NGram

java.lang.Object

org.apache.spark.ml.PipelineStage

org.apache.spark.ml.Transformer

org.apache.spark.ml.UnaryTransformer<scala.collection.Seq<java.lang.String>,scala.collection.Seq<java.lang.String>,NGram>

org.apache.spark.ml.feature.NGram

All Implemented Interfaces:

java.io.Serializable, Params, Identifiable

public class NGram
extends UnaryTransformer<scala.collection.Seq<java.lang.String>,scala.collection.Seq<java.lang.String>,NGram>

:: Experimental :: A feature transformer that converts the input array of strings into an array of n-grams. Null values in the input array are ignored. It returns an array of n-grams where each n-gram is represented by a space-separated string of words.

When the input is empty, an empty array is returned. When the input array length is less than n (number of elements per n-gram), no n-grams are returned.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
NGram()
NGram(java.lang.String uid)

Method Summary

Methods

Modifier and Type	Method and Description
protected static <T> T	$(Param<T> param)
static Params	clear(Param<?> param)
static T	copy(ParamMap extra)
protected static <T extends Params> T	copyValues(T to, ParamMap extra)
protected static <T extends Params> ParamMap	copyValues$default$2()
protected scala.Function1<scala.collection.Seq<java.lang.String>,scala.collection.Seq<java.lang.String>>	createTransformFunc() Creates the transform function using the given param map.
protected static <T extends Params> T	defaultCopy(ParamMap extra)
static java.lang.String	explainParam(Param<?> param)
static java.lang.String	explainParams()
static ParamMap	extractParamMap()
static ParamMap	extractParamMap(ParamMap extra)
static <T> scala.Option<T>	get(Param<T> param)
static <T> scala.Option<T>	getDefault(Param<T> param)
static java.lang.String	getInputCol()
int	getN()
static <T> T	getOrDefault(Param<T> param)
static java.lang.String	getOutputCol()
static Param<java.lang.Object>	getParam(java.lang.String paramName)
static <T> boolean	hasDefault(Param<T> param)
static boolean	hasParam(java.lang.String paramName)
protected static void	initializeLogIfNecessary(boolean isInterpreter)
static Param<java.lang.String>	inputCol()
static boolean	isDefined(Param<?> param)
static boolean	isSet(Param<?> param)
protected static boolean	isTraceEnabled()
static NGram	load(java.lang.String path)
protected static org.slf4j.Logger	log()
protected static void	logDebug(scala.Function0<java.lang.String> msg)
protected static void	logDebug(scala.Function0<java.lang.String> msg, java.lang.Throwable throwable)
protected static void	logError(scala.Function0<java.lang.String> msg)
protected static void	logError(scala.Function0<java.lang.String> msg, java.lang.Throwable throwable)
protected static void	logInfo(scala.Function0<java.lang.String> msg)
protected static void	logInfo(scala.Function0<java.lang.String> msg, java.lang.Throwable throwable)
protected static java.lang.String	logName()
protected static void	logTrace(scala.Function0<java.lang.String> msg)
protected static void	logTrace(scala.Function0<java.lang.String> msg, java.lang.Throwable throwable)
protected static void	logWarning(scala.Function0<java.lang.String> msg)
protected static void	logWarning(scala.Function0<java.lang.String> msg, java.lang.Throwable throwable)
IntParam	n() Minimum n-gram length, >= 1.
static Param<java.lang.String>	outputCol()
protected DataType	outputDataType() Returns the data type of the output column.
static Param<?>[]	params()
static void	save(java.lang.String path)
static <T> Params	set(Param<T> param, T value)
protected static Params	set(ParamPair<?> paramPair)
protected static Params	set(java.lang.String param, java.lang.Object value)
protected static <T> Params	setDefault(Param<T> param, T value)
protected static Params	setDefault(scala.collection.Seq<ParamPair<?>> paramPairs)
static T	setInputCol(java.lang.String value)
NGram	setN(int value)
static T	setOutputCol(java.lang.String value)
static java.lang.String	toString()
static Dataset<Row>	transform(Dataset<?> dataset)
static Dataset<Row>	transform(Dataset<?> dataset, ParamMap paramMap)
static Dataset<Row>	transform(Dataset<?> dataset, ParamPair<?> firstParamPair, ParamPair<?>... otherParamPairs)
static Dataset<Row>	transform(Dataset<?> dataset, ParamPair<?> firstParamPair, scala.collection.Seq<ParamPair<?>> otherParamPairs)
static StructType	transformSchema(StructType schema)
protected static StructType	transformSchema(StructType schema, boolean logging)
java.lang.String	uid() An immutable unique ID for the object and its derivatives.
protected void	validateInputType(DataType inputType) Validates the input type.
static void	validateParams()
static MLWriter	write()

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

copy, setInputCol, setOutputCol, transform, transformSchema

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

transform, transform, transform

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

transformSchema

Methods inherited from class java.lang.Object

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

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, validateParams

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

toString

Constructor Detail

NGram

public NGram(java.lang.String uid)

NGram

public NGram()

Method Detail

load

public static NGram load(java.lang.String path)

toString

public static java.lang.String toString()

params

public static Param<?>[] params()

validateParams

public static void validateParams()

explainParam

public static java.lang.String explainParam(Param<?> param)

explainParams

public static java.lang.String explainParams()

isSet

public static final boolean isSet(Param<?> param)

isDefined

public static final boolean isDefined(Param<?> param)

hasParam

public static boolean hasParam(java.lang.String paramName)

getParam

public static Param<java.lang.Object> getParam(java.lang.String paramName)

set

public static final <T> Params set(Param<T> param,
             T value)

set

protected static final Params set(java.lang.String param,
         java.lang.Object value)

set

protected static final Params set(ParamPair<?> paramPair)

get

public static final <T> scala.Option<T> get(Param<T> param)

clear

public static final Params clear(Param<?> param)

getOrDefault

public static final <T> T getOrDefault(Param<T> param)

$

protected static final <T> T $(Param<T> param)

setDefault

protected static final <T> Params setDefault(Param<T> param,
                    T value)

setDefault

protected static final Params setDefault(scala.collection.Seq<ParamPair<?>> paramPairs)

getDefault

public static final <T> scala.Option<T> getDefault(Param<T> param)

hasDefault

public static final <T> boolean hasDefault(Param<T> param)

defaultCopy

protected static final <T extends Params> T defaultCopy(ParamMap extra)

extractParamMap

public static final ParamMap extractParamMap(ParamMap extra)

extractParamMap

public static final ParamMap extractParamMap()

copyValues

protected static <T extends Params> T copyValues(T to,
                              ParamMap extra)

copyValues$default$2

protected static <T extends Params> ParamMap copyValues$default$2()

logName

protected static java.lang.String logName()

log

protected static org.slf4j.Logger log()

logInfo

protected static void logInfo(scala.Function0<java.lang.String> msg)

logDebug

protected static void logDebug(scala.Function0<java.lang.String> msg)

logTrace

protected static void logTrace(scala.Function0<java.lang.String> msg)

logWarning

protected static void logWarning(scala.Function0<java.lang.String> msg)

logError

protected static void logError(scala.Function0<java.lang.String> msg)

logInfo

protected static void logInfo(scala.Function0<java.lang.String> msg,
           java.lang.Throwable throwable)

logDebug

protected static void logDebug(scala.Function0<java.lang.String> msg,
            java.lang.Throwable throwable)

logTrace

protected static void logTrace(scala.Function0<java.lang.String> msg,
            java.lang.Throwable throwable)

logWarning

protected static void logWarning(scala.Function0<java.lang.String> msg,
              java.lang.Throwable throwable)

logError

protected static void logError(scala.Function0<java.lang.String> msg,
            java.lang.Throwable throwable)

isTraceEnabled

protected static boolean isTraceEnabled()

initializeLogIfNecessary

protected static void initializeLogIfNecessary(boolean isInterpreter)

transformSchema

protected static StructType transformSchema(StructType schema,
                         boolean logging)

transform

public static Dataset<Row> transform(Dataset<?> dataset,
                     ParamPair<?> firstParamPair,
                     scala.collection.Seq<ParamPair<?>> otherParamPairs)

transform

public static Dataset<Row> transform(Dataset<?> dataset,
                     ParamMap paramMap)

transform

public static Dataset<Row> transform(Dataset<?> dataset,
                     ParamPair<?> firstParamPair,
                     ParamPair<?>... otherParamPairs)

inputCol

public static final Param<java.lang.String> inputCol()

getInputCol

public static final java.lang.String getInputCol()

outputCol

public static final Param<java.lang.String> outputCol()

getOutputCol

public static final java.lang.String getOutputCol()

setInputCol

public static T setInputCol(java.lang.String value)

setOutputCol

public static T setOutputCol(java.lang.String value)

transformSchema

public static StructType transformSchema(StructType schema)

transform

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

copy

public static T copy(ParamMap extra)

save

public static void save(java.lang.String path)
                 throws java.io.IOException

Throws:

java.io.IOException

write

public static MLWriter write()

uid

public java.lang.String uid()

Description copied from interface: Identifiable

An immutable unique ID for the object and its derivatives.

Returns:

(undocumented)

n

public IntParam n()

Minimum n-gram length, >= 1. Default: 2, bigram features

Returns:

(undocumented)

setN

public NGram setN(int value)

getN

public int getN()

createTransformFunc

protected scala.Function1<scala.collection.Seq<java.lang.String>,scala.collection.Seq<java.lang.String>> createTransformFunc()

Description copied from class: UnaryTransformer

Creates the transform function using the given param map. The input param map already takes account of the embedded param map. So the param values should be determined solely by the input param map.

Specified by:

createTransformFunc in class UnaryTransformer<scala.collection.Seq<java.lang.String>,scala.collection.Seq<java.lang.String>,NGram>

Returns:

(undocumented)

validateInputType

protected void validateInputType(DataType inputType)

Description copied from class: UnaryTransformer

Validates the input type. Throw an exception if it is invalid.

Overrides:

validateInputType in class UnaryTransformer<scala.collection.Seq<java.lang.String>,scala.collection.Seq<java.lang.String>,NGram>

Parameters:

inputType - (undocumented)

outputDataType

protected DataType outputDataType()

Description copied from class: UnaryTransformer

Returns the data type of the output column.

Specified by:

outputDataType in class UnaryTransformer<scala.collection.Seq<java.lang.String>,scala.collection.Seq<java.lang.String>,NGram>

Returns:

(undocumented)