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Date: Wed, 15 Jul 2009 13:24:58 +0200
Message-ID: <b00c2d630907150424y1de25f7dpf621680710406b5@mail.gmail.com>
Subject: Re: problems with taste.
From: Laya Patwa <laya1uec@iitr.ernet.in>
To: mahout-user@lucene.apache.org
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Did you get any recommendations?

The preferences are different for each user in tdata.txt. In testdata.csv
the preferences are all 1, but the items are different for each user. I
think the pearson correlation is working, because the nearest n user list is
working and the code generates the nearest n user list.


On Wed, Jul 15, 2009 at 12:16 PM, Sean Owen <srowen@gmail.com> wrote:

> OK, hmm well it was kind of a long shot anyway. It should have worked even
> so.
>
> I see one data file attached. There are some blank lines at the top,
> though I don't think that will matter.
>
> You are putting quotes around the names. That means the item IDs have
> quotes in their names, which is not what I think you intend. For
> example, you do not have an item named 'red', you have an item named
> '"red"' in your model. If you are looking for recommendations that
> include the item 'red' you will not find any. But somehow I suspect
> this is not the problem you are talking about.
>
> What algorithm are you using -- one involving a correlation-based
> similarity metric like Pearson? I ask because most of your ratings
> have exactly the same rating, which will cause correlations to be
> undefined in some cases. You also have relatively little data. It may
> be that there are simply few or no defined similarities between users
> in the model and so no recommendations can be made.
>
> Add more, or more realistic, data and you should see better results
> perhaps.
>
>
> But I still then can't explain why two copies of the same file give
> different results. I might have to see the code.
> Yes do not send anything confidential.
>
>
> On Wed, Jul 15, 2009 at 11:10 AM, Laya Patwa<laya1uec@iitr.ernet.in>
> wrote:
> > Hey!
> > I followed your instructions. It doesn't work even when I put each file
> in
> > separate directory.
> > Maybe you should have a look at the code and the data files. I am
> attaching
> > 2 of the data files. I need to get permission for the 3rd one( it is also
> a
> > bit larger ). The code is almost the same as given in the documentation.
> It
> > is giving recommendations for the file testdata.csv.
> > Cheers,
> > Laya
> >
> > On Wed, Jul 15, 2009 at 11:43 AM, Sean Owen <srowen@gmail.com> wrote:
> >>
> >> Hmm, I might have guessed there is some file encoding issues, related
> >> to line breaks, since you say copying the file "breaks" it. But that
> >> would explain, I think, why a copy would *work* rather than fail.
> >>
> >> One thing to be careful of is that FileDataModel tries to be clever
> >> and allow you to post incremental updates to the data file by placing
> >> similarly-named files in the same directory. How have you named your
> >> files? To rule this out, put the files in separate directories, just
> >> to make sure.
> >>
> >> Otherwise perhaps you can send me a sample of the data file or a
> >> sample of your code to see what is going on.
> >>
> >> On Wed, Jul 15, 2009 at 10:23 AM, Laya Patwa<laya1uec@iitr.ernet.in>
> >> wrote:
> >> > Hi!
> >> > I am a student and right now I am working on a project named CoEUD. My
> >> > task
> >> > is to build a recommender system and I am using the taste recommender
> >> > library that comes with mahout.
> >> >
> >> > I downloaded the subversion and installed it using maven and cygwin on
> >> > windows and also on MacOS. I tried the grouplens demo that is given in
> >> > the
> >> > taste documentation and it also worked. Then I tried the example for
> >> > user
> >> > based recommender, but it is giving some problems as follows:
> >> > 1) I have 3 different data files with me and they are in CSV format
> >> > having
> >> > values of userID, itemID and preference. The recommendations are
> >> > generated
> >> > for 1 data file and not for the others. There are no errors. The
> program
> >> > runs and generates an empty recommendation list for other data files
> >> > 2)Another peculiar thing that is happening is that when I make a copy
> of
> >> > the
> >> > data file for which the user based recommender example is working and
> >> > use
> >> > this data file, the recommendation list generated is empty.
> >> >
> >> > I am stuck with the above 2 problems and can't figure out why the
> >> > recommendations are not generated for all the data files. Can you
> please
> >> > help me out.
> >> >
> >> > I am using eclipse.
> >> >
> >> > Cheers,
> >> > Laya
> >> >
> >
> >
>

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