RE: Consistent repeatable results for distributed ALS-WR recommender

2013-06-25 Thread Michael Kazekin
bject: http://www.stanford.edu/~boyd/cvxbook/bv_cvxbook.pdf Again thank you all for fruitful (at least for me :-P) discussion! > Subject: Re: Consistent repeatable results for distributed ALS-WR recommender > From: robin.e...@xense.co.uk > Date: Tue, 25 Jun 2013 09:10:23 +0

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-25 Thread Robin East
y and repeatability? (for example we > might want to track and compare the generated recommendation lists for > different parameters, such as the number of features or number of iterations > etc.) > M. > > >> Date: Mon, 24 Jun 2013 19:51:44 +0200 >> Subject: R

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Sean Owen
On Tue, Jun 25, 2013 at 12:44 AM, Michael Kazekin wrote: > But doesn't alternation guarantee convexity? No, the problem remains non-convex. At each step, where half the parameters are fixed, yes that constrained problem is convex. But each of these is not the same as the overall global problem be

RE: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Michael Kazekin
Thanks for clarification, Owen! > ALS starts from a random solution and this will result in a different > solution. The overall problem is non-convex and the process will not > necessarily converge to the same solution. But doesn't alternation guarantee convexity? > Randomness is a common feature o

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Koobas
Well, you know, the issue is there, whether we like it or not. Maybe replication is enough, maybe not. If there is a workshop on that issue, it's on the radar. http://beamtenherrschaft.blogspot.com/2013/06/acm-recsys-2013-workshop-on.html On Mon, Jun 24, 2013 at 6:36 PM, Sean Owen wrote: > Yeah

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Sean Owen
Yeah this has gone well off-road. ALS is not non-deterministic because of hardware errors or cosmic rays. It's also nothing to do with floating-point round-off, or certainly, that is not the primary source of non-determinism to several orders of magnitude. ALS starts from a random solution and th

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Ted Dunning
algorithm > implementation conserve (and why did authors added intentional > non-deterministic component to implementation). > > Date: Mon, 24 Jun 2013 14:43:59 -0700 > > Subject: Re: Consistent repeatable results for distributed ALS-WR > recommender > > From: dlie...@gmail.c

RE: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Michael Kazekin
f the algorithm implementation conserve (and why did authors added intentional non-deterministic component to implementation). > Date: Mon, 24 Jun 2013 14:43:59 -0700 > Subject: Re: Consistent repeatable results for distributed ALS-WR recommender > From: dlie...@gmail.com > To: user@mahout.a

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Koobas
There are definitely a > > lot > > > of such cases in Mahout. > > > > > > Another question is that afaik ALS-WR is deterministic by its > inception, > > so > > > > I'm trying to understand the reasons (and I'm as

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Dmitriy Lyubimov
> > > > > > > > > > Almost all methods -- even deterministic ones -- will have a > "credible > > > > interval" of prediction simply because method assumptions do not hold > > > 100% > > > > in real life, rea

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Koobas
t; for > > the specific implementation design. > > > > Thanks for a free lunch! ;) > > Cheers,Mike. > > > > > Date: Mon, 24 Jun 2013 13:13:20 -0700 > > > Subject: Re: Consistent repeatable results for distributed ALS-WR > > recommender > >

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Dmitriy Lyubimov
so > I'm trying to understand the reasons (and I'm assuming there are some) for > the specific implementation design. > > Thanks for a free lunch! ;) > Cheers,Mike. > > > Date: Mon, 24 Jun 2013 13:13:20 -0700 > > Subject: Re: Consistent repeatable results for dis

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Dmitriy Lyubimov
e effect on model credibility than achieving ideal training cost. > so I'm trying to understand the reasons (and I'm assuming there are some) > for the specific implementation design. > > Thanks for a free lunch! ;) > Cheers,Mike. > > > Date: Mon, 24 Jun 2013

RE: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Michael Kazekin
ns (and I'm assuming there are some) for the specific implementation design. Thanks for a free lunch! ;) Cheers,Mike. > Date: Mon, 24 Jun 2013 13:13:20 -0700 > Subject: Re: Consistent repeatable results for distributed ALS-WR recommender > From: dlie...@gmail.com > To: user@mahout.

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Dmitriy Lyubimov
nistic ones in this context, and, therefore, more "useful". Also see: "no free lunch theorem". > > From: ted.dunn...@gmail.com > > Date: Mon, 24 Jun 2013 20:46:43 +0100 > > Subject: Re: Consistent repeatable results for distributed ALS-WR > recommender > &

RE: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Michael Kazekin
Thank you, Ted! Any feedback on the usefulness of such functionality? Could it increase the 'playability' of the recommender? > From: ted.dunn...@gmail.com > Date: Mon, 24 Jun 2013 20:46:43 +0100 > Subject: Re: Consistent repeatable results for distributed ALS-WR rec

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Koobas
M. > > > > > > > Date: Mon, 24 Jun 2013 19:51:44 +0200 > > > Subject: Re: Consistent repeatable results for distributed ALS-WR > > recommender > > > From: s...@apache.org > > > To: user@mahout.apache.org > > > > > > The matrices of the

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Ted Dunning
dation > lists for different parameters, such as the number of features or number of > iterations etc.) > M. > > > > Date: Mon, 24 Jun 2013 19:51:44 +0200 > > Subject: Re: Consistent repeatable results for distributed ALS-WR > recommender > > From: s...@apache.org

RE: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Michael Kazekin
to track and compare the generated recommendation lists for different parameters, such as the number of features or number of iterations etc.) M. > Date: Mon, 24 Jun 2013 19:51:44 +0200 > Subject: Re: Consistent repeatable results for distributed ALS-WR recommender > From: s...@apache

Re: Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Sebastian Schelter
The matrices of the factorization are initalized randomly. If you fix the random seed (would require modification of the code) you should get exactly the same results. Am 24.06.2013 13:49 schrieb "Michael Kazekin" : > Hi! > Should I assume that under same dataset and same parameters for factorizer

Consistent repeatable results for distributed ALS-WR recommender

2013-06-24 Thread Michael Kazekin
Hi! Should I assume that under same dataset and same parameters for factorizer and recommender I will get the same results for any specific user? My current understanding that theoretically ALS-WR algorithm could guarantee this, but I was wondering could be there any numeric method issues and/or