Re: Mahout - Recommenditemvalue with magnitude of 1

With the older Hadoop-based recommenders you can use ratings or binary data. As Ted says binary data is pretty much always better. Your error is in treating any rating as a preference. A rating of 1 is unlikely to indicate a preference. Also you may have unresolved problems in your user and

Re: Mahout - Recommenditemvalue with magnitude of 1

On Sun, Nov 29, 2015 at 9:36 PM, Niklas Ekvall wrote: > My conclusion is that recommenditembased in Mahout works better for ratings > than binary data, what is your conclusions? > Still operator error somewhere. Binary data works much better as a real recommender.

Re: Mahout - Recommenditemvalue with magnitude of 1

Hello again Pat! I did find a testcase that I was able to recreate: 1,101,5.0 1,102,3.0 1,103,2.5 2,101,2.0 2,102,2.5 2,103,5.0 2,104,2.0 3,101,2.5 3,104,4.0 3,105,4.5 3,107,5.0 4,101,5.0 4,103,3.0 4,104,4.5 4,106,4.0 5,101,4.0 5,102,3.0 5,103,2.0 5,104,4.0 5,105,3.5 5,106,4.0 bin/mahout

Re: Mahout - Recommenditemvalue with magnitude of 1

I wouldn’t pre-filter but in any case the ids input to hadoop-mahout need to follow those rules. The new recommender I mentioned has no such requirements, it uses string IDs. On Nov 24, 2015, at 11:44 AM, Niklas Ekvall wrote: No, it does not start from 0 and does not

Re: Mahout - Recommenditemvalue with magnitude of 1

> On Nov 24, 2015, at 12:21 PM, Niklas Ekvall wrote: > > Okay! > > No pre-filter and the user/item ids should start from 0 and go as many user > and items there are. So, all the data we have should go into Mahout and we > filter inside Mahoutcorrect? Yes, but I

Mahout - Recommenditemvalue with magnitude of 1

No, it does not start from 0 and does not cover all number between 0 and the number of items/users. We do a prefiltering before (a user must have bought at lest 5 product and a product must have been bought by 3 users) we use Mahout on the dataset. Therefore we start with user 3, then it jumps to

Re: Mahout - Recommenditemvalue with magnitude of 1

Okay! No pre-filter and the user/item ids should start from 0 and go as many user and items there are. So, all the data we have should go into Mahout and we filter inside Mahoutcorrect? We do the same pre-filter for Spark item-similarity, is that wrong to? Best regards, Niklas On Tuesday,

Re: Mahout - Recommenditemvalue with magnitude of 1

Do your ids start with 0 and cover all numbers between 0 and the number of items -1 (same for user ids)? The old hadoop-mahout code required ordinal ids starting at 0 On Nov 24, 2015, at 8:19 AM, Niklas Ekvall wrote: Hi Pat, Here is some input: 3 7414 3

Re: Mahout - Recommenditemvalue with magnitude of 1

Hi Pat, Here is some input: 3 7414 3 12682 3 18947 3 19980 3 26975 3 54635 3 67789 3 73212 3 118932 3 138846 3 141268 5 3 5 2123 5 37955 5 39975 5 113289 6 3 6 456 6 2188 6

Mahout - Recommenditemvalue with magnitude of 1

Hello Mahout Users! I use today Mahout - Recommenditembased with Log-similarity to produce personal recommendations for Trigger Eamils in a offline mode. But when I produce e.g. 50 recommendations the rank value of the recommendations are always of magnitude 1. Why is this so? And, is the first

Re: Mahout - Recommenditemvalue with magnitude of 1

Sounds like you may not have the input right. Recommendations should be sorted by the strength and so shouldn’t all be 1 unless the data is very odd. Can you give us a small sample of the input? BTW a newer recommender using Mahout’s Spark based code and a search engine is here: