[MAHOUT-2019] SparseRowMatrix assign ops user for loops instead of iterateNonZero and so can be optimized

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 0.13.0
• Fix Version/s: classic-15.0
• Component/s: classic
• Assignee: Pat Ferrel
• Reporter: Pat Ferrel
• Created: 03/Oct/17 01:25
• Updated: 31/Jan/24 22:16
• Resolved: 31/Jan/24 21:49

Description

DRMs get blockified into SparseRowMatrix instances if the density is low. But SRM inherits the implementation of method like "assign" from AbstractMatrix, which uses nest for loops to traverse rows. For multiplying 2 matrices that are extremely sparse, the kind if data you see in collaborative filtering, this is extremely wasteful of execution time. Better to use a sparse vector's iterateNonZero Iterator for some function types.

Issue Links

• links to: GitHub Pull Request #342