in core/src/main/scala/com/spotify/featran/transformers/StandardScaler.scala [62:73]
override def buildFeatures(a: Option[Double], c: (Double, Double), fb: FeatureBuilder[_]): Unit =
a match {
case Some(x) =>
val r = (withStd, withMean) match {
case (true, true) => (x - c._1) / c._2
case (true, false) => (x - c._1) / c._2 + c._1
case (false, true) => x - c._1
case (false, false) => x
}
fb.add(name, r)
case None => fb.add(name, if (withMean) 0.0 else c._1)
}