Scala, get sum of multidimensional array

Question

By using trianglecount from GraphX, I retrieve the following array:

Array[(org.apache.spark.graphx.VertexId, Int)] = Array((1,1), (3,1), (2,1))

I'm trying to find a way to sum the second value of each element in the array. Thus the 1's in this example.

I haven't been able to find a method how to do this.

You'll do much better if you make an attempt and post what you have. No one can tell if you don't know Scala or are just too lazy from this question. — duffymo, Jun 29 '15 at 11:17
Understood. Had been busy with this for quite a while some days ago, so couldn't remember what I'd tried. Definitely get your point. Thanks — Ivo Van de Grift, Jun 29 '15 at 13:57

score 4 · Accepted Answer · answered Jun 29 '15 at 11:18

4

scala> val res = Array((1,1), (3,1), (2,1))
res: Array[(Int, Int)] = Array((1,1), (3,1), (2,1))

scala> res.map(_._2).sum
res7: Int = 3

or in one operation:

scala> res.foldLeft(0){case (acc, (k,v)) => acc +v }
res8: Int = 3

answered Jun 29 '15 at 11:18

Nikita

1 Answers1