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From Thomas Rewig <tre...@mufin.com>
Subject Re: problems with taste.
Date Wed, 15 Jul 2009 11:34:50 GMT
I just take a short look at the file. Maybe thats because all Users own 
all Collors - so there is nothing to recommend. Delete some Item for the 
User the recommendation is made for and you should get some 
recommendations.

Laya Patwa schrieb:
> 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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