[ 
https://issues.apache.org/jira/browse/SPARK-2426?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14377357#comment-14377357
 ] 

Debasish Das commented on SPARK-2426:
-------------------------------------

[~acopich] From your comment before "Anyway, l2 regularized stochastic matrix 
decomposition problem is defined as follows
Minimize w.r.t. W and H : ||R - W*H|| + \lambda(||W|| + ||H||)
under non-negativeness and normalization constraints.
||.|| stands for Frobenius norm (or l1).", could you please point me to a good 
reference with application to collaborative filtering/topic modeling ? 
Stochastic matrix decomposition is what we can do in this PR now 
https://github.com/apache/spark/pull/3221....

For MAP loss, I will open up a PR in a week through JIRA 
https://issues.apache.org/jira/browse/SPARK-6323...I am very curious how much 
slower we get compared to stochastic matrix decomposition using ALS

> Quadratic Minimization for MLlib ALS
> ------------------------------------
>
>                 Key: SPARK-2426
>                 URL: https://issues.apache.org/jira/browse/SPARK-2426
>             Project: Spark
>          Issue Type: New Feature
>          Components: MLlib
>    Affects Versions: 1.3.0
>            Reporter: Debasish Das
>            Assignee: Debasish Das
>   Original Estimate: 504h
>  Remaining Estimate: 504h
>
> Current ALS supports least squares and nonnegative least squares.
> I presented ADMM and IPM based Quadratic Minimization solvers to be used for 
> the following ALS problems:
> 1. ALS with bounds
> 2. ALS with L1 regularization
> 3. ALS with Equality constraint and bounds
> Initial runtime comparisons are presented at Spark Summit. 
> http://spark-summit.org/2014/talk/quadratic-programing-solver-for-non-negative-matrix-factorization-with-spark
> Based on Xiangrui's feedback I am currently comparing the ADMM based 
> Quadratic Minimization solvers with IPM based QpSolvers and the default 
> ALS/NNLS. I will keep updating the runtime comparison results.
> For integration the detailed plan is as follows:
> 1. Add QuadraticMinimizer and Proximal algorithms in mllib.optimization
> 2. Integrate QuadraticMinimizer in mllib ALS



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org

Reply via email to