CSSRState.scala

package com.typeclassified.cssr

import breeze.linalg.DenseVector
import com.typeclassified.cssr.parse.ParseNode

import scala.collection.mutable.ArrayBuffer

object CSSRState {
  def apply(histories: ArrayBuffer[ParseNode] = ArrayBuffer()) = new CSSRState(histories)
}

class CSSRState(val histories: ArrayBuffer[ParseNode]) {

  def addHistory(h: ParseNode): CSSRState = CSSRState(histories :+ h)

  def rmHistory(x: ParseNode): CSSRState = CSSRState(histories.filter(y => y != x))

  def frequency: DenseVector[Double] = histories.foldRight(frequency)((history, totalFreq) => totalFreq :+ history.frequency)

  def totalCounts: Int = frequency.foldRight(0d)(_ + _).toInt

  def normalDistribution: DenseVector[Double] = frequency :/ totalCounts.toDouble
}