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Posted to user@mahout.apache.org by Kevin Zhang <zh...@yahoo.com.INVALID> on 2015/03/03 06:13:06 UTC

spark-itemsimilarity cross-indicator-matrix and indicator-matrix

Hi Pat,

Thanks for the spark-itemsimilarity. I just ran it against my csv file which looks like below. My two actions are Liked and AddToCart. AddToCart is the main action.

usr000d3ca6655-c132-11e4-ac0a-0cc47a03334d Liked prd0000b5bc44b-fca8-4462-ba19-b9b2b823beb6
usr000e615c7ff-c132-11e4-ac0a-0cc47a03334d Liked prd0002da21ddf-6004-4611-9ef5-4fe96bbb969f
usr000d4821d99-c132-11e4-ac0a-0cc47a03334d AddToCart prd000075a5710-4890-4ec7-8faa-d9ffb0e94e6d
usr000cfd955f3-c132-11e4-ac0a-0cc47a03334d Liked prd0000b5bc44b-fca8-4462-ba19-b9b2b823beb6
usr0000dcd0443-c133-11e4-ac0a-0cc47a03334d Liked prd000e8149493-f3a1-491c-abe1-e7886e0286b9
usr000dfc1e861-c132-11e4-ac0a-0cc47a03334d Liked prd0009d6ff4b1-b139-46de-8d4c-425dbee5b4ca
usr000d2db7271-c132-11e4-ac0a-0cc47a03334d Liked prd000db1268fa-7fcb-4c84-8877-3b75f2748fda
usr000d274251f-c132-11e4-ac0a-0cc47a03334d Liked prd00078f2d7a1-9d6b-4175-96b5-d50ee35ab6db
usr000fb647da9-c132-11e4-ac0a-0cc47a03334d AddToCart prd000613c24dd-b838-433f-b1bc-e8e4dddae4d7
usr000d34d4713-c132-11e4-ac0a-0cc47a03334d Liked prd0007ca32be4-2443-4bba-83b4-f01382968c07

I can see there are two output files. One is under cross-indicator-matrix and the other under indicator-matrix.

I use Solr. I created a field called recommendation. It's indexed multivalues string field. I loaded indicator-matrix/part-00000 into this filed.

My question is what is cross-indicator-matrix for? What's the difference between indicator-matrix and cross-indicator-matrix? Do I need to create another Solr field for this cross-indicator-matrix? When I should use it? Is indicator-matrix for AddToCart and cross-indicator-matrix for Liked?

Thanks a lot,
Kevin

Re: spark-itemsimilarity cross-indicator-matrix and indicator-matrix

Posted by Pat Ferrel <pa...@occamsmachete.com>.

Some terminology changes will help. We’re changing “cross-indicator” into “cross-coocccurrence” indicator. Both are indicators that predict your primary action.

Cross-cooccurrence finds the secondary interactions that are indicators or predictors of the primary action. In your case AddToCart is what you want to recommend and therefor is your primary action and Liked is “scrubbed” with the cross-cooccurrence calculation to yield additional indicators.

The query will be

user-history-of-AddToCart -> recommendation field
user-history-of-Liked -> a new field—call it "liked-indicator"

You need to have a table with row ID = item-id and two multivalued fields, one containing the indicator-matrix values, and one containing the cross-indicator-matrix values (soon to be renamed "similarity-matrix" and "cross-simialrity-matrix”).

On Mar 2, 2015, at 9:13 PM, Kevin Zhang <zh...@yahoo.com.INVALID> wrote:

Hi Pat,

Thanks for the spark-itemsimilarity. I just ran it against my csv file which looks like below. My two actions are Liked and AddToCart. AddToCart is the main action.

I can see there are two output files. One is under cross-indicator-matrix and the other under indicator-matrix.

I use Solr. I created a field called recommendation. It's indexed multivalues string field. I loaded indicator-matrix/part-00000 into this filed.

Thanks a lot,
Kevin