[GitHub] incubator-spark pull request: [Proposal] Adding sparse data suppor...

[fommil]

Github user fommil commented on the pull request:

    https://github.com/apache/incubator-spark/pull/575#issuecomment-35126575
  
    @MLnick btw, I recently added some new ARPACK and linked-sparse matrix 
structures to MTJ that should give you all some ideas. BTW, I also recently 
created a "fast create" data structure (`CompressedColumns`) for building 
adjacency graphs: a fast compressed column structure: 
https://github.com/fommil/shelmet/blob/master/src/main/scala/org/shelmet/heap/parser/hack.scala#L153
 the  `LinkedMatrix` structure in the same file was a disappointment and a 
Scala equivalent of the new  `LinkedSparseMatrix` of 
https://github.com/fommil/matrix-toolkits-java/