[MAHOUT-1730] new mutable transposition view for in-core matrices.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.10.2
• Assignee: Dmitriy Lyubimov
• Reporter: Dmitriy Lyubimov
• Created: 02/Jun/15 23:55
• Updated: 07/Aug/15 15:56
• Resolved: 17/Jun/15 18:59

Description

in-core mxA.t rewrite with mostly two goals in mind:

(1) enable mutability , e.g.

for (col <- mxA.t) col := k

(2) translate matrix structural flavor for optimizers correctly. i.e. new SparseRowMatrix.t carries on as column-major structure.

Also it does unwrapping automatically, i.e. mxA.t.t eq mxA is true.

there are other smaller goals hit in this rewrite, e.g. various efficient assigns.

PR https://github.com/apache/mahout/pull/135