如何在Scala Spark中将稀疏矢量转换为密集？

Question

我有一个稀疏的向量:

(453,[0,4,11,16,39,56,109],[1.0,1.0,1.0,1.0,1.0,1.0,1.0])

我需要将其转换为密集向量(应该能够看到所有453个值).

如何在Scala Spark中做到这一点？

Answer 1

可以使用SparseVector的toDense方法完成:

val sv = Vectors.sparse(5, Array(0, 3), Array(1.5, -1.5))
sv.toDense
// res0: org.apache.spark.mllib.linalg.DenseVector = [1.5,0.0,0.0,-1.5,0.0]