From user-return-13343-apmail-mahout-user-archive=mahout.apache.org@mahout.apache.org Wed May 9 15:26:35 2012 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 4B63A9CB7 for ; Wed, 9 May 2012 15:26:35 +0000 (UTC) Received: (qmail 44981 invoked by uid 500); 9 May 2012 15:26:34 -0000 Delivered-To: apmail-mahout-user-archive@mahout.apache.org Received: (qmail 44932 invoked by uid 500); 9 May 2012 15:26:33 -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 44924 invoked by uid 99); 9 May 2012 15:26:33 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 09 May 2012 15:26:33 +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 (nike.apache.org: domain of srowen@gmail.com designates 209.85.215.42 as permitted sender) Received: from [209.85.215.42] (HELO mail-lpp01m010-f42.google.com) (209.85.215.42) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 09 May 2012 15:26:25 +0000 Received: by lagy4 with SMTP id y4so736632lag.1 for ; Wed, 09 May 2012 08:26:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=YWUcAPEh3KEhcuFbsM9/3JukTlflFwbZww8rqK3SotA=; b=ttHINh1BJ5RbbNHiwBKlfz8fuvs7dxQS6V8jrx51vo3iAura0DXnHqVTqy9cfSDI5s D4rsSeQDLZVj5dgiT7DWidZTa3tIKlDJVv6VFXhpNpITzmtkpU2JZFxGwSa7pJPjjAIy pY9q6yB6ZzR4aQpCLvhQdtr9T32ECFam4lRkN78bBP+FxQVkgjGLTFiavoTa3YspAtdU s2+XT7JuHESqhoZ5ki35DsxLtpGlYzBYvboachesRxrVIES5Xeb6KrIBcWc+DD5MK6ZZ A/tLl5+1L6X1oa9xxKZJsjl/d0uq191yLAezpakGDsSR/5HD7qm/WJ3whpwOahX55oWY me9Q== MIME-Version: 1.0 Received: by 10.152.131.74 with SMTP id ok10mr559937lab.17.1336577165495; Wed, 09 May 2012 08:26:05 -0700 (PDT) Received: by 10.112.133.103 with HTTP; Wed, 9 May 2012 08:26:05 -0700 (PDT) In-Reply-To: References: Date: Wed, 9 May 2012 16:26:05 +0100 Message-ID: Subject: Re: From Item-based Recommender to User-based Recommender From: Sean Owen To: user@mahout.apache.org Content-Type: multipart/alternative; boundary=f46d04339db42a0c5c04bf9c1fdd --f46d04339db42a0c5c04bf9c1fdd Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Ah, distributed implementation. no there is no such implementation now, but see: https://issues.apache.org/jira/browse/MAHOUT-1004 On Wed, May 9, 2012 at 4:19 PM, =E5=86=AF=E4=BC=9F wrote: > Sorry for my poor English. My question is like this: When I use > "org.apache.mahout.cf.taste.hadoop.item.RecommenderJob", my input file is > in the format: > "uid, itemid, rating" > "uid, itemid, rating" > "uid, itemid, rating" > According to the above input, > org.apache.mahout.cf.taste.hadoop.item.RecommenderJob will give item-base= d > recommendations. When I exchange the postions of uid and itemid, the inpu= t > file would be > "itemid, uid, rating" > "itemid, uid, rating" > "itemid, uid, rating" > According to the above input, > org.apache.mahout.cf.taste.hadoop.item.RecommenderJob would generate > user-based recommendation. Is that right? > > 2012/5/9 Sean Owen > > > Both of these have been implemented since before Mahout. Can you clarif= y? > > Don't understand at the moment. > > On May 9, 2012 3:42 PM, "=E5=86=AF=E4=BC=9F" = wrote: > > > > > I found that only item-based recommender is implemented in version-0.= 6. > > > When I want to use the user-based recommender, all I need to do is to > > > transpose the input, i.e., ---> > > rating>=EF=BC=8Cright? Is there any other differences between item-ba= sed and > > > user-based approach, which is not noticed by me? > > > > > > -- > > > Wei Feng > > > > > > > > > -- > Wei Feng > --f46d04339db42a0c5c04bf9c1fdd--