Slide 36
Slide 36 text
def normalization(dataArray: Array[Double]): RDD[Vector] =
{
val sums = dataArray.reduce((a, b) => a.zip(b).map(t => t._1 + t._2)
)
val sumSquares = dataArray.fold(new Array[Double](numCols))
(
(a,b) => a.zip(b).map(t => t._1 + t._2 * t._2))
val stdevs = sumSquares.zip(sums).map { cas
e
(sumSq, sum) => math.sqrt(n * sumSq - sum * sum) / count } va
l
val means = sums.map(_ / dataArray.count()
)
…
}