final class ChiSqSelector extends Selector[ChiSqSelectorModel]
Chi-Squared feature selection, which selects categorical features to use for predicting a
categorical label.
The selector supports different selection methods: numTopFeatures
, percentile
, fpr
,
fdr
, fwe
.
numTopFeatures
chooses a fixed number of top features according to a chi-squared test.percentile
is similar but chooses a fraction of all features instead of a fixed number.fpr
chooses all features whose p-value are below a threshold, thus controlling the false positive rate of selection.fdr
uses the [Benjamini-Hochberg procedure] (https://en.wikipedia.org/wiki/False_discovery_rate#Benjamini.E2.80.93Hochberg_procedure) to choose all features whose false discovery rate is below a threshold.fwe
chooses all features whose p-values are below a threshold. The threshold is scaled by 1/numFeatures, thus controlling the family-wise error rate of selection. By default, the selection method isnumTopFeatures
, with the default number of top features set to 50.
- Annotations
- @deprecated @Since( "1.6.0" )
- Deprecated
(Since version 3.1.1) use UnivariateFeatureSelector instead
- Source
- ChiSqSelector.scala
- Grouped
- Alphabetic
- By Inheritance
- ChiSqSelector
- Selector
- DefaultParamsWritable
- MLWritable
- SelectorParams
- HasOutputCol
- HasLabelCol
- HasFeaturesCol
- Estimator
- PipelineStage
- Logging
- Params
- Serializable
- Serializable
- Identifiable
- AnyRef
- Any
- Hide All
- Show All
- Public
- All
Parameters
A list of (hyper-)parameter keys this algorithm can take. Users can set and get the parameter values through setters and getters, respectively.
-
final
val
fdr: DoubleParam
The upper bound of the expected false discovery rate.
The upper bound of the expected false discovery rate. Only applicable when selectorType = "fdr". Default value is 0.05.
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
-
final
val
featuresCol: Param[String]
Param for features column name.
Param for features column name.
- Definition Classes
- HasFeaturesCol
-
final
val
fpr: DoubleParam
The highest p-value for features to be kept.
The highest p-value for features to be kept. Only applicable when selectorType = "fpr". Default value is 0.05.
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
-
final
val
fwe: DoubleParam
The upper bound of the expected family-wise error rate.
The upper bound of the expected family-wise error rate. Only applicable when selectorType = "fwe". Default value is 0.05.
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
-
final
val
labelCol: Param[String]
Param for label column name.
Param for label column name.
- Definition Classes
- HasLabelCol
-
final
val
numTopFeatures: IntParam
Number of features that selector will select, ordered by ascending p-value.
Number of features that selector will select, ordered by ascending p-value. If the number of features is less than numTopFeatures, then this will select all features. Only applicable when selectorType = "numTopFeatures". The default value of numTopFeatures is 50.
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
-
final
val
outputCol: Param[String]
Param for output column name.
Param for output column name.
- Definition Classes
- HasOutputCol
-
final
val
percentile: DoubleParam
Percentile of features that selector will select, ordered by ascending p-value.
Percentile of features that selector will select, ordered by ascending p-value. Only applicable when selectorType = "percentile". Default value is 0.1.
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
-
final
val
selectorType: Param[String]
The selector type.
The selector type. Supported options: "numTopFeatures" (default), "percentile", "fpr", "fdr", "fwe"
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
Members
-
final
def
clear(param: Param[_]): ChiSqSelector.this.type
Clears the user-supplied value for the input param.
Clears the user-supplied value for the input param.
- Definition Classes
- Params
-
def
copy(extra: ParamMap): ChiSqSelector
Creates a copy of this instance with the same UID and some extra 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()
.- Definition Classes
- ChiSqSelector → Selector → Estimator → PipelineStage → Params
- Annotations
- @Since( "1.6.0" )
-
def
explainParam(param: Param[_]): String
Explains a param.
Explains a param.
- param
input param, must belong to this instance.
- returns
a string that contains the input param name, doc, and optionally its default value and the user-supplied value
- Definition Classes
- Params
-
def
explainParams(): String
Explains all params of this instance.
Explains all params of this instance. See
explainParam()
.- Definition Classes
- Params
-
final
def
extractParamMap(): ParamMap
extractParamMap
with no extra values.extractParamMap
with no extra values.- Definition Classes
- Params
-
final
def
extractParamMap(extra: ParamMap): ParamMap
Extracts the embedded default param values and user-supplied values, and then merges them with extra values from input into a flat param map, where the latter value is used if there exist conflicts, i.e., with ordering: default param values less than user-supplied values less than extra.
Extracts the embedded default param values and user-supplied values, and then merges them with extra values from input into a flat param map, where the latter value is used if there exist conflicts, i.e., with ordering: default param values less than user-supplied values less than extra.
- Definition Classes
- Params
-
def
fit(dataset: Dataset[_]): ChiSqSelectorModel
Fits a model to the input data.
Fits a model to the input data.
- Definition Classes
- ChiSqSelector → Selector → Estimator
- Annotations
- @Since( "1.6.0" )
-
def
fit(dataset: Dataset[_], paramMaps: Seq[ParamMap]): Seq[ChiSqSelectorModel]
Fits multiple models to the input data with multiple sets of parameters.
Fits multiple models to the input data with multiple sets of parameters. The default implementation uses a for loop on each parameter map. Subclasses could override this to optimize multi-model training.
- dataset
input dataset
- paramMaps
An array of parameter maps. These values override any specified in this Estimator's embedded ParamMap.
- returns
fitted models, matching the input parameter maps
- Definition Classes
- Estimator
- Annotations
- @Since( "2.0.0" )
-
def
fit(dataset: Dataset[_], paramMap: ParamMap): ChiSqSelectorModel
Fits a single model to the input data with provided parameter map.
Fits a single model to the input data with provided parameter map.
- dataset
input dataset
- paramMap
Parameter map. These values override any specified in this Estimator's embedded ParamMap.
- returns
fitted model
- Definition Classes
- Estimator
- Annotations
- @Since( "2.0.0" )
-
def
fit(dataset: Dataset[_], firstParamPair: ParamPair[_], otherParamPairs: ParamPair[_]*): ChiSqSelectorModel
Fits a single model to the input data with optional parameters.
Fits a single model to the input data with optional parameters.
- dataset
input dataset
- firstParamPair
the first param pair, overrides embedded params
- otherParamPairs
other param pairs. These values override any specified in this Estimator's embedded ParamMap.
- returns
fitted model
- Definition Classes
- Estimator
- Annotations
- @Since( "2.0.0" ) @varargs()
-
final
def
get[T](param: Param[T]): Option[T]
Optionally returns the user-supplied value of a param.
Optionally returns the user-supplied value of a param.
- Definition Classes
- Params
-
final
def
getDefault[T](param: Param[T]): Option[T]
Gets the default value of a parameter.
Gets the default value of a parameter.
- Definition Classes
- Params
-
final
def
getOrDefault[T](param: Param[T]): T
Gets the value of a param in the embedded param map or its default value.
Gets the value of a param in the embedded param map or its default value. Throws an exception if neither is set.
- Definition Classes
- Params
-
def
getParam(paramName: String): Param[Any]
Gets a param by its name.
Gets a param by its name.
- Definition Classes
- Params
-
final
def
hasDefault[T](param: Param[T]): Boolean
Tests whether the input param has a default value set.
Tests whether the input param has a default value set.
- Definition Classes
- Params
-
def
hasParam(paramName: String): Boolean
Tests whether this instance contains a param with a given name.
Tests whether this instance contains a param with a given name.
- Definition Classes
- Params
-
final
def
isDefined(param: Param[_]): Boolean
Checks whether a param is explicitly set or has a default value.
Checks whether a param is explicitly set or has a default value.
- Definition Classes
- Params
-
final
def
isSet(param: Param[_]): Boolean
Checks whether a param is explicitly set.
Checks whether a param is explicitly set.
- Definition Classes
- Params
-
lazy val
params: Array[Param[_]]
Returns all params sorted by their names.
Returns all params sorted by their names. The default implementation uses Java reflection to list all public methods that have no arguments and return Param.
- Definition Classes
- Params
- Note
Developer should not use this method in constructor because we cannot guarantee that this variable gets initialized before other params.
-
def
save(path: String): Unit
Saves this ML instance to the input path, a shortcut of
write.save(path)
.Saves this ML instance to the input path, a shortcut of
write.save(path)
.- Definition Classes
- MLWritable
- Annotations
- @Since( "1.6.0" ) @throws( ... )
-
final
def
set[T](param: Param[T], value: T): ChiSqSelector.this.type
Sets a parameter in the embedded param map.
Sets a parameter in the embedded param map.
- Definition Classes
- Params
-
def
toString(): String
- Definition Classes
- Identifiable → AnyRef → Any
-
def
transformSchema(schema: StructType): StructType
Check transform validity and derive the output schema from the input schema.
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 byParam.validate()
.Typical implementation should first conduct verification on schema change and parameter validity, including complex parameter interaction checks.
- Definition Classes
- ChiSqSelector → Selector → PipelineStage
- Annotations
- @Since( "1.6.0" )
-
val
uid: String
An immutable unique ID for the object and its derivatives.
An immutable unique ID for the object and its derivatives.
- Definition Classes
- ChiSqSelector → Identifiable
- Annotations
- @Since( "1.6.0" )
-
def
write: MLWriter
Returns an
MLWriter
instance for this ML instance.Returns an
MLWriter
instance for this ML instance.- Definition Classes
- DefaultParamsWritable → MLWritable
Parameter setters
-
def
setFdr(value: Double): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "2.2.0" )
-
def
setFeaturesCol(value: String): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "1.6.0" )
-
def
setFpr(value: Double): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "2.1.0" )
-
def
setFwe(value: Double): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "2.2.0" )
-
def
setLabelCol(value: String): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "1.6.0" )
-
def
setNumTopFeatures(value: Int): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "1.6.0" )
-
def
setOutputCol(value: String): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "1.6.0" )
-
def
setPercentile(value: Double): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "2.1.0" )
-
def
setSelectorType(value: String): ChiSqSelector.this.type
- Definition Classes
- ChiSqSelector → Selector
- Annotations
- @Since( "2.1.0" )
Parameter getters
-
def
getFdr: Double
- Definition Classes
- SelectorParams
-
final
def
getFeaturesCol: String
- Definition Classes
- HasFeaturesCol
-
def
getFpr: Double
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
-
def
getFwe: Double
- Definition Classes
- SelectorParams
-
final
def
getLabelCol: String
- Definition Classes
- HasLabelCol
-
def
getNumTopFeatures: Int
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
-
final
def
getOutputCol: String
- Definition Classes
- HasOutputCol
-
def
getPercentile: Double
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )
-
def
getSelectorType: String
- Definition Classes
- SelectorParams
- Annotations
- @Since( "3.1.0" )