You create the indicator and cross-indicator matrices with —omitStrength then if you are using a database with solr or elasticsearch you will create a table:
item ID, list of indicator Item IDs, list of cross-indicator item IDs 3 columns. All IDs will be like “nexus” in the example—they are your application’s item IDs. The second and third column contain lists of item IDs. There are several ways you can do this either by using a multi-valued field (array of IDs) or a space delimited string depending on how you want to integrate with your search engine and database. Check the instructions for your particular search engine. At the time you want to recommend, take the user’s history of the primary action (purchase in the example) and map it to the "list of indicator Item IDs” field. Take the user’s history of the secondary action (view in the example) and map it to the "list of cross-indicator Item IDs” field. Then perform the search engine query and you’ll get back a list of item IDs to recommend. Filter out any items that the user has in their history (if you wish) and recommend the items in the order they were returned This blog explains more: http://occamsmachete.com/ml/2014/09/09/mahout-on-spark-whats-new-in-recommenders-part-2/ Ted’s book gives an example architecture: https://www.mapr.com/practical-machine-learning On Sep 18, 2014, at 10:00 AM, pol <[email protected]> wrote: Hi, All I saw spark-itemsimilarity doc at http://mahout.apache.org/users/recommender/intro-cooccurrence-spark.html, but I don’t understand how can creating a recommender by spark-itemsimilarity? I don’t understand "3 Creating a Recommender" chapter. For input of the form: u1,purchase,iphone u1,purchase,ipad u2,purchase,nexus u2,purchase,galaxy u3,purchase,surface u4,purchase,iphone u4,purchase,galaxy u1,view,iphone u1,view,ipad u1,view,nexus u1,view,galaxy u2,view,iphone u2,view,ipad u2,view,nexus u2,view,galaxy u3,view,surface u3,view,nexus u4,view,iphone u4,view,ipad u4,view,galaxy output out-path |-- indicator-matrix - TDF part files \-- cross-indicator-matrix - TDF part-files The indicator matrix will contain the lines: galaxy\tnexus:1.7260924347106847 ipad\tiphone:1.7260924347106847 nexus\tgalaxy:1.7260924347106847 iphone\tipad:1.7260924347106847 surface The cross-indicator matrix will contain: iphone\tnexus:1.7260924347106847 iphone:1.7260924347106847 ipad:1.7260924347106847 galaxy:1.7260924347106847 ipad\tnexus:0.6795961471815897 iphone:0.6795961471815897 ipad:0.6795961471815897 galaxy:0.6795961471815897 nexus\tnexus:0.6795961471815897 iphone:0.6795961471815897 ipad:0.6795961471815897 galaxy:0.6795961471815897 galaxy\tnexus:1.7260924347106847 iphone:1.7260924347106847 ipad:1.7260924347106847 galaxy:1.7260924347106847 surface\tsurface:4.498681156950466 nexus:0.6795961471815897 ————---- Now，u4 view nexus, how to recommend for u4 by the above of output? Thanks.
