Packages

class RFormula extends Estimator[RFormulaModel] with RFormulaBase with DefaultParamsWritable

Implements the transforms required for fitting a dataset against an R model formula. Currently we support a limited subset of the R operators, including '~', '.', ':', '+', '-', '*' and '^'. Also see the R formula docs here: http://stat.ethz.ch/R-manual/R-patched/library/stats/html/formula.html

The basic operators are:

  • ~ separate target and terms
  • + concat terms, "+ 0" means removing intercept
  • - remove a term, "- 1" means removing intercept
  • : interaction (multiplication for numeric values, or binarized categorical values)
  • . all columns except target
  • * factor crossing, includes the terms and interactions between them
  • ^ factor crossing to a specified degree

Suppose a and b are double columns, we use the following simple examples to illustrate the effect of RFormula:

  • y ~ a + b means model y ~ w0 + w1 * a + w2 * b where w0 is the intercept and w1, w2 are coefficients.
  • y ~ a + b + a:b - 1 means model y ~ w1 * a + w2 * b + w3 * a * b where w1, w2, w3 are coefficients.
  • y ~ a * b means model y ~ w0 + w1 * a + w2 * b + w3 * a * b where w0 is the intercept and w1, w2, w3 are coefficients
  • y ~ (a + b)^2 means model y ~ w0 + w1 * a + w2 * b + w3 * a * b where w0 is the intercept and w1, w2, w3 are coefficients

RFormula produces a vector column of features and a double or string column of label. Like when formulas are used in R for linear regression, string input columns will be one-hot encoded, and numeric columns will be cast to doubles. If the label column is of type string, it will be first transformed to double with StringIndexer. If the label column does not exist in the DataFrame, the output label column will be created from the specified response variable in the formula.

Annotations
@Since( "1.5.0" )
Source
RFormula.scala
Linear Supertypes
DefaultParamsWritable, MLWritable, RFormulaBase, HasHandleInvalid, HasLabelCol, HasFeaturesCol, Estimator[RFormulaModel], PipelineStage, Logging, Params, Serializable, Serializable, Identifiable, AnyRef, Any
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Inherited
  1. RFormula
  2. DefaultParamsWritable
  3. MLWritable
  4. RFormulaBase
  5. HasHandleInvalid
  6. HasLabelCol
  7. HasFeaturesCol
  8. Estimator
  9. PipelineStage
  10. Logging
  11. Params
  12. Serializable
  13. Serializable
  14. Identifiable
  15. AnyRef
  16. Any
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Visibility
  1. Public
  2. All

Instance Constructors

  1. new RFormula()
    Annotations
    @Since( "1.5.0" )
  2. new RFormula(uid: String)
    Annotations
    @Since( "1.5.0" )

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def $[T](param: Param[T]): T

    An alias for getOrDefault().

    An alias for getOrDefault().

    Attributes
    protected
    Definition Classes
    Params
  4. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. final def clear(param: Param[_]): RFormula.this.type

    Clears the user-supplied value for the input param.

    Clears the user-supplied value for the input param.

    Definition Classes
    Params
  7. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  8. def copy(extra: ParamMap): RFormula

    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
    RFormula → Estimator → PipelineStage → Params
    Annotations
    @Since( "1.5.0" )
  9. 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 to paramMap. 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

    Attributes
    protected
    Definition Classes
    Params
  10. 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
    protected
    Definition Classes
    Params
  11. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  12. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  13. 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
  14. def explainParams(): String

    Explains all params of this instance.

    Explains all params of this instance. See explainParam().

    Definition Classes
    Params
  15. final def extractParamMap(): ParamMap

    extractParamMap with no extra values.

    extractParamMap with no extra values.

    Definition Classes
    Params
  16. 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
  17. final val featuresCol: Param[String]

    Param for features column name.

    Param for features column name.

    Definition Classes
    HasFeaturesCol
  18. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  19. def fit(dataset: Dataset[_]): RFormulaModel

    Fits a model to the input data.

    Fits a model to the input data.

    Definition Classes
    RFormula → Estimator
    Annotations
    @Since( "2.0.0" )
  20. def fit(dataset: Dataset[_], paramMaps: Seq[ParamMap]): Seq[RFormulaModel]

    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" )
  21. def fit(dataset: Dataset[_], paramMap: ParamMap): RFormulaModel

    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" )
  22. def fit(dataset: Dataset[_], firstParamPair: ParamPair[_], otherParamPairs: ParamPair[_]*): RFormulaModel

    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()
  23. val forceIndexLabel: BooleanParam

    Force to index label whether it is numeric or string type.

    Force to index label whether it is numeric or string type. Usually we index label only when it is string type. If the formula was used by classification algorithms, we can force to index label even it is numeric type by setting this param with true. Default: false.

    Definition Classes
    RFormulaBase
    Annotations
    @Since( "2.1.0" )
  24. val formula: Param[String]

    R formula parameter.

    R formula parameter. The formula is provided in string form.

    Definition Classes
    RFormulaBase
    Annotations
    @Since( "1.5.0" )
  25. 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
  26. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  27. 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
  28. final def getFeaturesCol: String

    Definition Classes
    HasFeaturesCol
  29. def getForceIndexLabel: Boolean

    Definition Classes
    RFormulaBase
    Annotations
    @Since( "2.1.0" )
  30. def getFormula: String

    Definition Classes
    RFormulaBase
    Annotations
    @Since( "1.5.0" )
  31. final def getHandleInvalid: String

    Definition Classes
    HasHandleInvalid
  32. final def getLabelCol: String

    Definition Classes
    HasLabelCol
  33. 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
  34. def getParam(paramName: String): Param[Any]

    Gets a param by its name.

    Gets a param by its name.

    Definition Classes
    Params
  35. def getStringIndexerOrderType: String

    Definition Classes
    RFormulaBase
    Annotations
    @Since( "2.3.0" )
  36. val handleInvalid: Param[String]

    Param for how to handle invalid data (unseen or NULL values) in features and label column of string type.

    Param for how to handle invalid data (unseen or NULL values) in features and label column of string type. Options are 'skip' (filter out rows with invalid data), 'error' (throw an error), or 'keep' (put invalid data in a special additional bucket, at index numLabels). Default: "error"

    Definition Classes
    RFormulaBase → HasHandleInvalid
    Annotations
    @Since( "2.3.0" )
  37. 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
  38. def hasLabelCol(schema: StructType): Boolean
    Attributes
    protected
    Definition Classes
    RFormulaBase
  39. 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
  40. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  41. def initializeLogIfNecessary(isInterpreter: Boolean, silent: Boolean): Boolean
    Attributes
    protected
    Definition Classes
    Logging
  42. def initializeLogIfNecessary(isInterpreter: Boolean): Unit
    Attributes
    protected
    Definition Classes
    Logging
  43. 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
  44. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  45. final def isSet(param: Param[_]): Boolean

    Checks whether a param is explicitly set.

    Checks whether a param is explicitly set.

    Definition Classes
    Params
  46. def isTraceEnabled(): Boolean
    Attributes
    protected
    Definition Classes
    Logging
  47. final val labelCol: Param[String]

    Param for label column name.

    Param for label column name.

    Definition Classes
    HasLabelCol
  48. def log: Logger
    Attributes
    protected
    Definition Classes
    Logging
  49. def logDebug(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  50. def logDebug(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  51. def logError(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  52. def logError(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  53. def logInfo(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  54. def logInfo(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  55. def logName: String
    Attributes
    protected
    Definition Classes
    Logging
  56. def logTrace(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  57. def logTrace(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  58. def logWarning(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  59. def logWarning(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  60. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  61. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  62. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  63. 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.

  64. 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( ... )
  65. final def set(paramPair: ParamPair[_]): RFormula.this.type

    Sets a parameter in the embedded param map.

    Sets a parameter in the embedded param map.

    Attributes
    protected
    Definition Classes
    Params
  66. final def set(param: String, value: Any): RFormula.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
  67. final def set[T](param: Param[T], value: T): RFormula.this.type

    Sets a parameter in the embedded param map.

    Sets a parameter in the embedded param map.

    Definition Classes
    Params
  68. final def setDefault(paramPairs: ParamPair[_]*): RFormula.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
  69. final def setDefault[T](param: Param[T], value: T): RFormula.this.type

    Sets a default value for a param.

    Sets a default value for a param.

    param

    param to set the default value. Make sure that this param is initialized before this method gets called.

    value

    the default value

    Attributes
    protected
    Definition Classes
    Params
  70. def setFeaturesCol(value: String): RFormula.this.type

    Annotations
    @Since( "1.5.0" )
  71. def setForceIndexLabel(value: Boolean): RFormula.this.type

    Annotations
    @Since( "2.1.0" )
  72. def setFormula(value: String): RFormula.this.type

    Sets the formula to use for this transformer.

    Sets the formula to use for this transformer. Must be called before use.

    value

    an R formula in string form (e.g. "y ~ x + z")

    Annotations
    @Since( "1.5.0" )
  73. def setHandleInvalid(value: String): RFormula.this.type

    Annotations
    @Since( "2.3.0" )
  74. def setLabelCol(value: String): RFormula.this.type

    Annotations
    @Since( "1.5.0" )
  75. def setStringIndexerOrderType(value: String): RFormula.this.type

    Annotations
    @Since( "2.3.0" )
  76. final val stringIndexerOrderType: Param[String]

    Param for how to order categories of a string FEATURE column used by StringIndexer.

    Param for how to order categories of a string FEATURE column used by StringIndexer. The last category after ordering is dropped when encoding strings. Supported options: 'frequencyDesc', 'frequencyAsc', 'alphabetDesc', 'alphabetAsc'. The default value is 'frequencyDesc'. When the ordering is set to 'alphabetDesc', RFormula drops the same category as R when encoding strings.

    The options are explained using an example 'b', 'a', 'b', 'a', 'c', 'b':

    +-----------------+---------------------------------------+----------------------------------+
|      Option     | Category mapped to 0 by StringIndexer |  Category dropped by RFormula    |
+-----------------+---------------------------------------+----------------------------------+
| 'frequencyDesc' | most frequent category ('b')          | least frequent category ('c')    |
| 'frequencyAsc'  | least frequent category ('c')         | most frequent category ('b')     |
| 'alphabetDesc'  | last alphabetical category ('c')      | first alphabetical category ('a')|
| 'alphabetAsc'   | first alphabetical category ('a')     | last alphabetical category ('c') |
+-----------------+---------------------------------------+----------------------------------+

    Note that this ordering option is NOT used for the label column. When the label column is indexed, it uses the default descending frequency ordering in StringIndexer.

    Definition Classes
    RFormulaBase
    Annotations
    @Since( "2.3.0" )
  77. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  78. def toString(): String
    Definition Classes
    RFormula → Identifiable → AnyRef → Any
    Annotations
    @Since( "2.0.0" )
  79. 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 by Param.validate().

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

    Definition Classes
    RFormula → PipelineStage
    Annotations
    @Since( "1.5.0" )
  80. 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()
  81. 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
    RFormula → Identifiable
    Annotations
    @Since( "1.5.0" )
  82. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  83. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  84. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  85. def write: MLWriter

    Returns an MLWriter instance for this ML instance.

    Returns an MLWriter instance for this ML instance.

    Definition Classes
    DefaultParamsWritable → MLWritable

Inherited from DefaultParamsWritable

Inherited from MLWritable

Inherited from RFormulaBase

Inherited from HasHandleInvalid

Inherited from HasLabelCol

Inherited from HasFeaturesCol

Inherited from Estimator[RFormulaModel]

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