A HashMap provides a way to store and retrieve key-value pairs in a way that is efficient and fast. An internal HashMap is also known as an open addressing or closed hashing. HashMap is a specific implementation of a HashMap that stores the key-value pairs directly within an array. In...
Vector, Vectors} import org.apache.spark.rdd.RDD override def computeCorrelationMatrix(X: RDD[Vector]): Matrix = { // ((columnIndex, value), rowUid) val colBased = X.zipWithUniqueId().flatMap { case