updateGuess.kt

fun updateGuess(
    guess: Pair<Double, Double>,
    learningRate: Double,
    videoGameData: Array<Pair<Double, Double>>
): Pair<Double, Double> {
    val (m, b)  = guess
    val mGradient = videoGameData.fold(0.0) { acc: Double, pair: Pair<Double, Double> ->
        val (x, y) = pair
        acc + ((((m * x) + b) - y) * x)
    } / videoGameData.size
    val bGradient = videoGameData.fold(0.0) { acc: Double, pair: Pair<Double, Double> ->
        val (x, y) = pair
        acc + ((((m * x) + b) - y))
    } / videoGameData.size
    val newM = m - (learningRate * mGradient)
    val newB = b - (learningRate * bGradient)
    return Pair(newM, newB)
}