class ALS extends Estimator[ALSModel] with ALSParams with DefaultParamsWritable
Alternating Least Squares (ALS) matrix factorization.
ALS attempts to estimate the ratings matrix R as the product of two lower-rank matrices,
X and Y, i.e. X * Yt = R. Typically these approximations are called 'factor' matrices.
The general approach is iterative. During each iteration, one of the factor matrices is held
constant, while the other is solved for using least squares. The newly-solved factor matrix is
then held constant while solving for the other factor matrix.
This is a blocked implementation of the ALS factorization algorithm that groups the two sets of factors (referred to as "users" and "products") into blocks and reduces communication by only sending one copy of each user vector to each product block on each iteration, and only for the product blocks that need that user's feature vector. This is achieved by pre-computing some information about the ratings matrix to determine the "out-links" of each user (which blocks of products it will contribute to) and "in-link" information for each product (which of the feature vectors it receives from each user block it will depend on). This allows us to send only an array of feature vectors between each user block and product block, and have the product block find the users' ratings and update the products based on these messages.
For implicit preference data, the algorithm used is based on "Collaborative Filtering for Implicit Feedback Datasets", available at https://doi.org/10.1109/ICDM.2008.22, adapted for the blocked approach used here.
Essentially instead of finding the low-rank approximations to the rating matrix R,
this finds the approximations for a preference matrix P where the elements of P are 1 if
r is greater than 0 and 0 if r is less than or equal to 0. The ratings then act as 'confidence'
values related to strength of indicated user
preferences rather than explicit ratings given to items.
Note: the input rating dataset to the ALS implementation should be deterministic.
Nondeterministic data can cause failure during fitting ALS model.
For example, an order-sensitive operation like sampling after a repartition makes dataset
output nondeterministic, like dataset.repartition(2).sample(false, 0.5, 1618).
Checkpointing sampled dataset or adding a sort before sampling can help make the dataset
deterministic.
- Annotations
 - @Since( "1.3.0" )
 - Source
 - ALS.scala
 
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- ALS
 - DefaultParamsWritable
 - MLWritable
 - ALSParams
 - HasSeed
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 - HasRegParam
 - HasMaxIter
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 - HasBlockSize
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 - Estimator
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        val
      
      
        alpha: DoubleParam
      
      
      
Param for the alpha parameter in the implicit preference formulation (nonnegative).
Param for the alpha parameter in the implicit preference formulation (nonnegative). Default: 1.0
- Definition Classes
 - ALSParams
 
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        asInstanceOf[T0]: T0
      
      
      
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        final 
        val
      
      
        blockSize: IntParam
      
      
      
Param for block size for stacking input data in matrices.
Param for block size for stacking input data in matrices. Data is stacked within partitions. If block size is more than remaining data in a partition then it is adjusted to the size of this data..
- Definition Classes
 - HasBlockSize
 
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        def
      
      
        checkIntegers(dataset: Dataset[_], colName: String): Column
      
      
      
Attempts to safely cast a user/item id to an Int.
Attempts to safely cast a user/item id to an Int. Throws an exception if the value is out of integer range or contains a fractional part.
- Attributes
 - protected[recommendation]
 - Definition Classes
 - ALSModelParams
 
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        final 
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        checkpointInterval: IntParam
      
      
      
Param for set checkpoint interval (>= 1) or disable checkpoint (-1).
Param for set checkpoint interval (>= 1) or disable checkpoint (-1). E.g. 10 means that the cache will get checkpointed every 10 iterations. Note: this setting will be ignored if the checkpoint directory is not set in the SparkContext.
- Definition Classes
 - HasCheckpointInterval
 
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        final 
        def
      
      
        clear(param: Param[_]): ALS.this.type
      
      
      
Clears the user-supplied value for the input param.
Clears the user-supplied value for the input param.
- Definition Classes
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        val
      
      
        coldStartStrategy: Param[String]
      
      
      
Param for strategy for dealing with unknown or new users/items at prediction time.
Param for strategy for dealing with unknown or new users/items at prediction time. This may be useful in cross-validation or production scenarios, for handling user/item ids the model has not seen in the training data. Supported values: - "nan": predicted value for unknown ids will be NaN. - "drop": rows in the input DataFrame containing unknown ids will be dropped from the output DataFrame containing predictions. Default: "nan".
- Definition Classes
 - ALSModelParams
 
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        def
      
      
        copy(extra: ParamMap): ALS
      
      
      
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
 - ALS → Estimator → PipelineStage → Params
 - Annotations
 - @Since( "1.5.0" )
 
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        def
      
      
        copyValues[T <: Params](to: T, extra: ParamMap = ParamMap.empty): T
      
      
      
Copies param values from this instance to another instance for params shared by them.
Copies param values from this instance to another instance for params shared by them.
This handles default Params and explicitly set Params separately. Default Params are copied from and to
defaultParamMap, and explicitly set Params are copied from and toparamMap. Warning: This implicitly assumes that this Params instance and the target instance share the same set of default Params.- to
 the target instance, which should work with the same set of default Params as this source instance
- extra
 extra params to be copied to the target's
paramMap- returns
 the target instance with param values copied
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        final 
        def
      
      
        defaultCopy[T <: Params](extra: ParamMap): T
      
      
      
Default implementation of copy with extra params.
Default implementation of copy with extra params. It tries to create a new instance with the same UID. Then it copies the embedded and extra parameters over and returns the new instance.
- Attributes
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 - Definition Classes
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        eq(arg0: AnyRef): Boolean
      
      
      
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        def
      
      
        equals(arg0: Any): Boolean
      
      
      
- Definition Classes
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        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
 
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        def
      
      
        explainParams(): String
      
      
      
Explains all params of this instance.
Explains all params of this instance. See
explainParam().- Definition Classes
 - Params
 
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        final 
        def
      
      
        extractParamMap(): ParamMap
      
      
      
extractParamMapwith no extra values.extractParamMapwith no extra values.- Definition Classes
 - Params
 
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        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
 
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        val
      
      
        finalStorageLevel: Param[String]
      
      
      
Param for StorageLevel for ALS model factors.
Param for StorageLevel for ALS model factors. Pass in a string representation of
StorageLevel. Default: "MEMORY_AND_DISK".- Definition Classes
 - ALSParams
 
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        def
      
      
        finalize(): Unit
      
      
      
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        def
      
      
        fit(dataset: Dataset[_]): ALSModel
      
      
      
Fits a model to the input data.
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        def
      
      
        fit(dataset: Dataset[_], paramMaps: Seq[ParamMap]): Seq[ALSModel]
      
      
      
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): ALSModel
      
      
      
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[_]*): ALSModel
      
      
      
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
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        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
 
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        def
      
      
        getAlpha: Double
      
      
      
- Definition Classes
 - ALSParams
 
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        getBlockSize: Int
      
      
      
- Definition Classes
 - HasBlockSize
 
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        getCheckpointInterval: Int
      
      
      
- Definition Classes
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        getClass(): Class[_]
      
      
      
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        def
      
      
        getColdStartStrategy: String
      
      
      
- Definition Classes
 - ALSModelParams
 
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        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
 
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        def
      
      
        getFinalStorageLevel: String
      
      
      
- Definition Classes
 - ALSParams
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        getImplicitPrefs: Boolean
      
      
      
- Definition Classes
 - ALSParams
 
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        def
      
      
        getIntermediateStorageLevel: String
      
      
      
- Definition Classes
 - ALSParams
 
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        def
      
      
        getItemCol: String
      
      
      
- Definition Classes
 - ALSModelParams
 
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        final 
        def
      
      
        getMaxIter: Int
      
      
      
- Definition Classes
 - HasMaxIter
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        getNonnegative: Boolean
      
      
      
- Definition Classes
 - ALSParams
 
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        def
      
      
        getNumItemBlocks: Int
      
      
      
- Definition Classes
 - ALSParams
 
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        def
      
      
        getNumUserBlocks: Int
      
      
      
- Definition Classes
 - ALSParams
 
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        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
 
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        final 
        def
      
      
        getPredictionCol: String
      
      
      
- Definition Classes
 - HasPredictionCol
 
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        def
      
      
        getRank: Int
      
      
      
- Definition Classes
 - ALSParams
 
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        def
      
      
        getRatingCol: String
      
      
      
- Definition Classes
 - ALSParams
 
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        final 
        def
      
      
        getRegParam: Double
      
      
      
- Definition Classes
 - HasRegParam
 
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        final 
        def
      
      
        getSeed: Long
      
      
      
- Definition Classes
 - HasSeed
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        getUserCol: String
      
      
      
- Definition Classes
 - ALSModelParams
 
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        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
 
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        def
      
      
        hashCode(): Int
      
      
      
- Definition Classes
 - AnyRef → Any
 - Annotations
 - @native()
 
 - 
      
      
      
        
      
    
      
        
        val
      
      
        implicitPrefs: BooleanParam
      
      
      
Param to decide whether to use implicit preference.
Param to decide whether to use implicit preference. Default: false
- Definition Classes
 - ALSParams
 
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        def
      
      
        initializeLogIfNecessary(isInterpreter: Boolean, silent: Boolean): Boolean
      
      
      
- Attributes
 - protected
 - Definition Classes
 - Logging
 
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        def
      
      
        initializeLogIfNecessary(isInterpreter: Boolean): Unit
      
      
      
- Attributes
 - protected
 - Definition Classes
 - Logging
 
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        val
      
      
        intermediateStorageLevel: Param[String]
      
      
      
Param for StorageLevel for intermediate datasets.
Param for StorageLevel for intermediate datasets. Pass in a string representation of
StorageLevel. Cannot be "NONE". Default: "MEMORY_AND_DISK".- Definition Classes
 - ALSParams
 
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        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
 
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        final 
        def
      
      
        isInstanceOf[T0]: Boolean
      
      
      
- Definition Classes
 - Any
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        isSet(param: Param[_]): Boolean
      
      
      
Checks whether a param is explicitly set.
Checks whether a param is explicitly set.
- Definition Classes
 - Params
 
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        def
      
      
        isTraceEnabled(): Boolean
      
      
      
- Attributes
 - protected
 - Definition Classes
 - Logging
 
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        val
      
      
        itemCol: Param[String]
      
      
      
Param for the column name for item ids.
Param for the column name for item ids. Ids must be integers. Other numeric types are supported for this column, but will be cast to integers as long as they fall within the integer value range. Default: "item"
- Definition Classes
 - ALSModelParams
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        log: Logger
      
      
      
- Attributes
 - protected
 - Definition Classes
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        def
      
      
        logDebug(msg: ⇒ String, throwable: Throwable): Unit
      
      
      
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        def
      
      
        logDebug(msg: ⇒ String): Unit
      
      
      
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        def
      
      
        logError(msg: ⇒ String, throwable: Throwable): Unit
      
      
      
- Attributes
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        def
      
      
        logError(msg: ⇒ String): Unit
      
      
      
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        def
      
      
        logInfo(msg: ⇒ String, throwable: Throwable): Unit
      
      
      
- Attributes
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 - Logging
 
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        def
      
      
        logInfo(msg: ⇒ String): Unit
      
      
      
- Attributes
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 - Logging
 
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        def
      
      
        logName: String
      
      
      
- Attributes
 - protected
 - Definition Classes
 - Logging
 
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        def
      
      
        logTrace(msg: ⇒ String, throwable: Throwable): Unit
      
      
      
- Attributes
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 - Logging
 
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        def
      
      
        logTrace(msg: ⇒ String): Unit
      
      
      
- Attributes
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        def
      
      
        logWarning(msg: ⇒ String, throwable: Throwable): Unit
      
      
      
- Attributes
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 - Logging
 
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        def
      
      
        logWarning(msg: ⇒ String): Unit
      
      
      
- Attributes
 - protected
 - Definition Classes
 - Logging
 
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        final 
        val
      
      
        maxIter: IntParam
      
      
      
Param for maximum number of iterations (>= 0).
Param for maximum number of iterations (>= 0).
- Definition Classes
 - HasMaxIter
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        ne(arg0: AnyRef): Boolean
      
      
      
- Definition Classes
 - AnyRef
 
 - 
      
      
      
        
      
    
      
        
        val
      
      
        nonnegative: BooleanParam
      
      
      
Param for whether to apply nonnegativity constraints.
Param for whether to apply nonnegativity constraints. Default: false
- Definition Classes
 - ALSParams
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        notify(): Unit
      
      
      
- Definition Classes
 - AnyRef
 - Annotations
 - @native()
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        notifyAll(): Unit
      
      
      
- Definition Classes
 - AnyRef
 - Annotations
 - @native()
 
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        val
      
      
        numItemBlocks: IntParam
      
      
      
Param for number of item blocks (positive).
Param for number of item blocks (positive). Default: 10
- Definition Classes
 - ALSParams
 
 - 
      
      
      
        
      
    
      
        
        val
      
      
        numUserBlocks: IntParam
      
      
      
Param for number of user blocks (positive).
Param for number of user blocks (positive). Default: 10
- Definition Classes
 - ALSParams
 
 - 
      
      
      
        
      
    
      
        
        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.
 - 
      
      
      
        
      
    
      
        final 
        val
      
      
        predictionCol: Param[String]
      
      
      
Param for prediction column name.
Param for prediction column name.
- Definition Classes
 - HasPredictionCol
 
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        val
      
      
        rank: IntParam
      
      
      
Param for rank of the matrix factorization (positive).
Param for rank of the matrix factorization (positive). Default: 10
- Definition Classes
 - ALSParams
 
 - 
      
      
      
        
      
    
      
        
        val
      
      
        ratingCol: Param[String]
      
      
      
Param for the column name for ratings.
Param for the column name for ratings. Default: "rating"
- Definition Classes
 - ALSParams
 
 - 
      
      
      
        
      
    
      
        final 
        val
      
      
        regParam: DoubleParam
      
      
      
Param for regularization parameter (>= 0).
Param for regularization parameter (>= 0).
- Definition Classes
 - HasRegParam
 
 - 
      
      
      
        
      
    
      
        
        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 
        val
      
      
        seed: LongParam
      
      
      
Param for random seed.
Param for random seed.
- Definition Classes
 - HasSeed
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        set(paramPair: ParamPair[_]): ALS.this.type
      
      
      
Sets a parameter in the embedded param map.
Sets a parameter in the embedded param map.
- Attributes
 - protected
 - Definition Classes
 - Params
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        set(param: String, value: Any): ALS.this.type
      
      
      
Sets a parameter (by name) in the embedded param map.
Sets a parameter (by name) in the embedded param map.
- Attributes
 - protected
 - Definition Classes
 - Params
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        set[T](param: Param[T], value: T): ALS.this.type
      
      
      
Sets a parameter in the embedded param map.
Sets a parameter in the embedded param map.
- Definition Classes
 - Params
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setAlpha(value: Double): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setBlockSize(value: Int): ALS.this.type
      
      
      
Set block size for stacking input data in matrices.
Set block size for stacking input data in matrices. Default is 4096.
- Annotations
 - @Since( "3.0.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setCheckpointInterval(value: Int): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.4.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setColdStartStrategy(value: String): ALS.this.type
      
      
      
- Annotations
 - @Since( "2.2.0" )
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        setDefault(paramPairs: ParamPair[_]*): ALS.this.type
      
      
      
Sets default values for a list of params.
Sets default values for a list of params.
Note: Java developers should use the single-parameter
setDefault. Annotating this with varargs can cause compilation failures due to a Scala compiler bug. See SPARK-9268.- paramPairs
 a list of param pairs that specify params and their default values to set respectively. Make sure that the params are initialized before this method gets called.
- Attributes
 - protected
 - Definition Classes
 - Params
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        setDefault[T](param: Param[T], value: T): ALS.this.type
      
      
      
Sets a default value for a param.
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setFinalStorageLevel(value: String): ALS.this.type
      
      
      
- Annotations
 - @Since( "2.0.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setImplicitPrefs(value: Boolean): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setIntermediateStorageLevel(value: String): ALS.this.type
      
      
      
- Annotations
 - @Since( "2.0.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setItemCol(value: String): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setMaxIter(value: Int): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setNonnegative(value: Boolean): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setNumBlocks(value: Int): ALS.this.type
      
      
      
Sets both numUserBlocks and numItemBlocks to the specific value.
Sets both numUserBlocks and numItemBlocks to the specific value.
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setNumItemBlocks(value: Int): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setNumUserBlocks(value: Int): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setPredictionCol(value: String): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setRank(value: Int): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setRatingCol(value: String): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setRegParam(value: Double): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setSeed(value: Long): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        setUserCol(value: String): ALS.this.type
      
      
      
- Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        synchronized[T0](arg0: ⇒ T0): T0
      
      
      
- Definition Classes
 - AnyRef
 
 - 
      
      
      
        
      
    
      
        
        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
transformSchemaand 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
 - ALS → PipelineStage
 - Annotations
 - @Since( "1.3.0" )
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        transformSchema(schema: StructType, logging: Boolean): StructType
      
      
      
:: DeveloperApi ::
:: DeveloperApi ::
Derives the output schema from the input schema and parameters, optionally with logging.
This should be optimistic. If it is unclear whether the schema will be valid, then it should be assumed valid until proven otherwise.
- Attributes
 - protected
 - Definition Classes
 - PipelineStage
 - Annotations
 - @DeveloperApi()
 
 - 
      
      
      
        
      
    
      
        
        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
 - ALS → Identifiable
 - Annotations
 - @Since( "1.4.0" )
 
 - 
      
      
      
        
      
    
      
        
        val
      
      
        userCol: Param[String]
      
      
      
Param for the column name for user ids.
Param for the column name for user ids. Ids must be integers. Other numeric types are supported for this column, but will be cast to integers as long as they fall within the integer value range. Default: "user"
- Definition Classes
 - ALSModelParams
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        validateAndTransformSchema(schema: StructType): StructType
      
      
      
Validates and transforms the input schema.
Validates and transforms the input schema.
- schema
 input schema
- returns
 output schema
- Attributes
 - protected
 - Definition Classes
 - ALSParams
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        wait(): Unit
      
      
      
- Definition Classes
 - AnyRef
 - Annotations
 - @throws( ... )
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        wait(arg0: Long, arg1: Int): Unit
      
      
      
- Definition Classes
 - AnyRef
 - Annotations
 - @throws( ... )
 
 - 
      
      
      
        
      
    
      
        final 
        def
      
      
        wait(arg0: Long): Unit
      
      
      
- Definition Classes
 - AnyRef
 - Annotations
 - @throws( ... ) @native()
 
 - 
      
      
      
        
      
    
      
        
        def
      
      
        write: MLWriter
      
      
      
Returns an
MLWriterinstance for this ML instance.Returns an
MLWriterinstance for this ML instance.- Definition Classes
 - DefaultParamsWritable → MLWritable
 
 
Inherited from DefaultParamsWritable
Inherited from MLWritable
Inherited from ALSParams
Inherited from HasSeed
Inherited from HasCheckpointInterval
Inherited from HasRegParam
Inherited from HasMaxIter
Inherited from ALSModelParams
Inherited from HasBlockSize
Inherited from HasPredictionCol
Inherited from PipelineStage
Inherited from Logging
Inherited from Params
Inherited from Serializable
Inherited from Serializable
Inherited from Identifiable
Inherited from AnyRef
Inherited from Any
Parameters
A list of (hyper-)parameter keys this algorithm can take. Users can set and get the parameter values through setters and getters, respectively.
Members
Parameter setters
Parameter getters
(expert-only) Parameters
A list of advanced, expert-only (hyper-)parameter keys this algorithm can take. Users can set and get the parameter values through setters and getters, respectively.