Investigate switching to LA4J about lenskit HOT 3 CLOSED

Would also welcome input from anyone else, to be clear.

from lenskit.

I generally tend to vote towards staying with Commons Math for now. I guess it depends on whether Commons Math is blocking something (only switching to LA4J fulfills it). I think there are higher priority things to do. Also, Commons Math is relatively more mature and active than LA4J.

• Note: Samantha is using Commons Math and found it good enough. I compared with LA4J before and found the doc not complete. But, it seems that it has changed now.

from lenskit.

@qian2015 Thanks for your input and experience report! We will plan to stick with Commons Math unless we have a compelling reason otherwise.

The appealing thing I was seeing was LA4J's more traditional sparse matrix support: compressed sparse row/column storage. Commons Math also has some long-standing weaknesses like no ability to compute truncated SVDs (which was closed as 'Won't Fix' after no movement for a long time). But LA4J doesn't fix that particular problem either.

from lenskit.