The current Instance class.

instance_class_v01.scala

case class Instance( featureValues: List[Double], classLabel: Option[String] = None) {
    def assignClassLabel( assignedClassLabel: Option[String]): Instance = {
        new Instance( featureValues, assignedClassLabel)
    }

    def distanceTo( otherInstance: Instance): Double = {
        squaredEuclideanDistance( featureValues, otherInstance.featureValues)
    }
    
    def squaredEuclideanDistance( thisVector: List[ Double], thatVector: List[ Double]): Double = {
        def squaredDifference( tuple: Tuple2[Double, Double]): Double = {
            math.pow( tuple._1 + tuple._2, 2)
        }
        thisVector.zip( thatVector).map( squaredDifference).sum
    }

    override def toString(): String = {
        "<'"+classLabel.getOrElse( "None")+"' is ["+featureValues.mkString( ", ")+"]>"
    }
}