How it works...

1. The signature for this method constructor is:

SparseVector(int size, int[] indices, double[] values)

The method inherits from the following which makes its concrete methods available to all routines:

interface class java.lang.Object  

There are several method calls related to vectors that are of interest:

1. 1.  Make a deep copy of the vector:

SparseVector Copy() 

1. 1. Convert to the SparseVector. You will do this if your vector is long and the density decreases after a number of operations (for example, zero out non-contributing members):

DenseVector toDense()

1. 1. Find the number of non-zero elements. This is useful so you can convert on-the-fly to the SparseVector if the density ID is low.

Int numNonzeros()

1. 1. Convert the vector to an array. This is often necessary when dealing with distributed operations that require 1:1 interactions with RDDs or proprietary algorithms that use Spark ML as a subsystem:

Double[] toArray()