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Date: Sun, 29 Sep 2013 19:24:33 +0100
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Subject: Re: Getting rating for all the files
From: Deepak Subhramanian <deepak.subhramanian@gmail.com>
To: user@mahout.apache.org
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Thanks Nick. I am planning to give a try with userbasedrecommendation since
there are low no of users. I dont see recommenduserbased option in the
commandline utility for Mahout. Does that mean I have to write a Java
Program to use the UserBasedRecommender ?


On Sun, Sep 29, 2013 at 7:22 PM, Martin, Nick <NiMartin@pssd.com> wrote:

> I'l need to defer to one of the other math whizzes on the potential
> reasons for recommendations for certain users not appearing. My suspicion
> is that you would either not have sufficient co-occurrence of specific
> users/items to support a recommendation or you may need to experiment with
> a different similarity measure.
>
> Anyone else want to weigh in?
>
>
>
> Sent from my iPhone
>
> On Sep 29, 2013, at 1:14 PM, "Deepak Subhramanian" <
> deepak.subhramanian@gmail.com> wrote:
>
> > Sorry . My mistake . I am getting the lower ratings for some of the users
> > and items. But my issue is not solved . I am not getting ratings for some
> > of the users and some of the ratings.
> >
> > My userFile has 8000 users and my itemsFile has 4000 Items  . But I get
> > recommendations for only 5000 users and  1500 items. And the maximum no
> of
> > recommendations given is 258. What can be the reasons that there  is no
> > items recommendations for 3000 users and 2500 items. Is it because there
> is
> > no similarities exist between those users and items  ?
> >
> >
> > On Sun, Sep 29, 2013 at 4:46 PM, Deepak Subhramanian <
> > deepak.subhramanian@gmail.com> wrote:
> >
> >> Thanks Nick. As I mentioned earleir I am getting  ratings only for the
> top
> >> recommended products instead of ratings for 4000 products I am giving
> >> numRecommendations parameter to 4000 and maxPrefsPerUser  to 4000.
> Should
> >> it give 4000 items in the list for each user ? For some reasons the
> >> output for items which are having lower ratings is not displayed.  I see
> >> the default limit is 10.
> >>
> >> I am not sure if I am not getting ratings for 4000 items because I am
> >> passing the wrong options for the  mahout version or is it an issue with
> >> mahout ver 0.7. I am using 0.7 -mahout-examples-0.7-cdh4.3.1.jar .
> >>
> >> I see the parameter name changed in the latest version I checked from
> git
> >> - 0.9-SNAPSHOT
> >>
> >> maxPrefsPerUserConsidered =
> jobConf.getInt(MAX_PREFS_PER_USER_CONSIDERED,
> >> DEFAULT_MAX_PREFS_PER_USER_CONSIDERED);
> >>
> >> Will using a latest version help ?
> >>
> >>
> >>
> >>
> >>
> >> On Sun, Sep 29, 2013 at 12:29 PM, Martin, Nick <NiMartin@pssd.com>
> wrote:
> >>
> >>> There should be a score after each recommended item (i.e. 123456:2.6)
> in
> >>> your output. Lower scores would be the ones you're interested in.
> >>>
> >>> Sent from my iPhone
> >>>
> >>> On Sep 28, 2013, at 8:25 AM, "Deepak Subhramanian" <
> >>> deepak.subhramanian@gmail.com> wrote:
> >>>
> >>>> Hi
> >>>>
> >>>> I am trying to predict the ratings for some items for some users using
> >>> item
> >>>> based collaborative filtering. I tried using the mahout
> >>> recommenditembased
> >>>> , but it shows only the top 10 items or I can increase it by passing
> the
> >>>> --numRecommendations parameter. But it doesnt shows items which has
> >>> lower
> >>>> predicted rating . What is the best approach to get ratings for items
> >>> which
> >>>> has low predicted rating ?
> >>>>
> >>>>
> >>>> I tried this command.
> >>>>
> >>>> mahout recommenditembased --input mahoutrecoinput --usersFile
> >>>> recouserlist  --itemsFile  recoitemlist --output
> >>>> /mahoutrecooutputpearsonnew -s SIMILARITY_PEARSON_CORRELATION
> >>>> --numRecommendations 4000  --maxPrefsPerUser 4000
> >>>>
> >>>> Also I tried using the estimatePreference method on the recommender.
> >>>>
> >>>> Please help .
> >>
> >>
> >>
> >> --
> >> Deepak Subhramanian
> >
> >
> >
> > --
> > Deepak Subhramanian
>


-- 
Deepak Subhramanian

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