Likelihood ratio test for binomials

gistfile1.scala

    def likelihoodRatio(k1 : Int, n1 : Int, k2 : Int, n2 : Int) = {
        def kLogP(k : Int, p : Double) = if(k == 0) 0 else k * math.log(p)
        def logL(p : Double, k : Int, n : Int) = kLogP(k, p) + kLogP(n - k, 1 - p)

        val p1 = k1.toDouble / n1.toDouble
        val p2 = k2.toDouble / n2.toDouble
        val p = (k1 + k2).toDouble / (n1 + n2).toDouble
        logL(p1, k1, n1) + logL(p2, k2, n2) - logL(p, k1, n1) - logL(p, k2, n2)
    }