R Formula
===========

RFormula feature selection, RFormula selects columns specified by an R model formula. Currently we support a limited subset of the R operators, including ‘~’, ‘.’, ‘:’, ‘+’, and ‘-‘

Type
--------- 

ml-transformer

Class
--------- 

fire.nodes.ml.NodeRFormula

Fields
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.. list-table::
      :widths: 10 5 10
      :header-rows: 1

      * - Name
        - Title
        - Description
      * - featuresCol
        - Features Column 
        - The features column name
      * - formula
        - Formula
        - formula
      * - labelCol
        - Label Column
        - The label column name


Details
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RFormula selects columns specified by an R model formula. Currently we support a limited subset of the R operators, including ‘~’, ‘.’, ‘:’, ‘+’, and ‘-‘. 


More details are available at : https://spark.apache.org/docs/latest/ml-features.html#rformula


Examples
-------
The below example is available at : https://spark.apache.org/docs/latest/ml-features.html#rformula
+++++++++++++++



import org.apache.spark.ml.feature.RFormula


val dataset = spark.createDataFrame(Seq(

  (7, "US", 18, 1.0),

  (8, "CA", 12, 0.0),

  (9, "NZ", 15, 0.0)

)).toDF("id", "country", "hour", "clicked")


val formula = new RFormula()

  .setFormula("clicked ~ country + hour")

  .setFeaturesCol("features")

  .setLabelCol("label")


val output = formula.fit(dataset).transform(dataset)

output.select("features", "label").show()