Return-Path: X-Original-To: apmail-mahout-user-archive@www.apache.org Delivered-To: apmail-mahout-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id C641E106F2 for ; Wed, 11 Sep 2013 07:20:02 +0000 (UTC) Received: (qmail 54296 invoked by uid 500); 11 Sep 2013 07:19:59 -0000 Delivered-To: apmail-mahout-user-archive@mahout.apache.org Received: (qmail 54205 invoked by uid 500); 11 Sep 2013 07:19:58 -0000 Mailing-List: contact user-help@mahout.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@mahout.apache.org Delivered-To: mailing list user@mahout.apache.org Received: (qmail 54192 invoked by uid 99); 11 Sep 2013 07:19:56 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 11 Sep 2013 07:19:56 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of ted.dunning@gmail.com designates 209.85.223.179 as permitted sender) Received: from [209.85.223.179] (HELO mail-ie0-f179.google.com) (209.85.223.179) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 11 Sep 2013 07:19:52 +0000 Received: by mail-ie0-f179.google.com with SMTP id e14so3950514iej.38 for ; Wed, 11 Sep 2013 00:19:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=QZM/9K8y27jkojtvRGlkRbI6wQx/idi/B7eEOe+1+28=; b=nS1NNvTlaioMugRiWnf++QhP6xBeiNevKPTQYK2OeUtb+HCwMAXCBa3a1b5bKV2GDU 5t733f3FDq4GQBw8HSjSkOJCiRGfsb652gxqRWLVMmDOkwe6Ga65PGgSqN2mXmIr2bNC NBb7S5MjadJv7ec2MspEkRkcva4oAR3bXK2jAjICwLJEjYfKq0Ct498aYQA6txM7y6+M 9jWTNNvkQiyQj0j3nvPvIpSMkLe0yKjWsjIrccuCXHjp4uqQUbmoeat9GhzA1ve6Qsc/ B/DtouCblgQ4ApC6nbpzMHTDeMDxVCDvSvGIW01mXXtrPEbfRSgk3yXVcHWeAYerDt0S JYhw== X-Received: by 10.42.163.132 with SMTP id c4mr25790icy.68.1378883971695; Wed, 11 Sep 2013 00:19:31 -0700 (PDT) MIME-Version: 1.0 Received: by 10.64.224.145 with HTTP; Wed, 11 Sep 2013 00:19:01 -0700 (PDT) In-Reply-To: References: From: Ted Dunning Date: Wed, 11 Sep 2013 00:19:01 -0700 Message-ID: Subject: Re: Tuning parameters for ALS-WR To: "user@mahout.apache.org" Content-Type: multipart/alternative; boundary=90e6ba2121a351cc9e04e61671bc X-Virus-Checked: Checked by ClamAV on apache.org --90e6ba2121a351cc9e04e61671bc Content-Type: text/plain; charset=UTF-8 On Wed, Sep 11, 2013 at 12:07 AM, Sean Owen wrote: > > 2. Do we have to tune the "similarityclass" parameter in item-based CF? > If > > so, do we compare the mean average precision values based on validation > > data, and then report the same for the test set? > > > > > Yes you are conceptually looking over the entire hyper-parameter space. If > the similarity metric is one of those, you are trying different metrics. > Grid search, just brute-force trying combinations, works for 1-2 > hyper-parameters. Otherwise I'd try randomly choosing parameters, really, > or else it will take way too long to explore. You try to pick > hyper-parameters 'nearer' to those that have yielded better scores. > Or use a real exploration algorithm. For my favorite (hear that horn blowing?) see this article on recorded step meta-mutation. The idea is a randomized search, but with something akin to momentum. This lets you search nasty landscapes with pretty pretty good robustness and smooth ones with fast convergence. The code and theory are simple and there is an implementation in Mahout. --90e6ba2121a351cc9e04e61671bc--