change to sort by confidence instead of lift score and change default parameter values

Author: Kenneth Chan

README.md

@@ -6,6 +6,10 @@ Please refer to http://docs.prediction.io/templates/complementarypurchase/quicks
 
 ## Versions
 
+### v0.3.3
+
+- change to sort by confidence instead of lift score and change default parameter values
+
 ### v0.3.2
 
 - lower the default minSupport and minConfidence parameter setting

engine.json

@@ -13,8 +13,8 @@
       "params": {
         "basketWindow" : 120,
         "maxRuleLength" : 2,
-        "minSupport": 0.05,
-        "minConfidence": 0.2,
+        "minSupport": 0.001,
+        "minConfidence": 0.1,
         "minLift" : 1.0,
         "minBasketSize" : 2,
         "maxNumRulesPerCond": 5

src/main/scala/Algorithm.scala

@@ -108,7 +108,7 @@ class Algorithm(val ap: AlgorithmParams)
     val sortedRules = rules.groupByKey
       .mapValues(iter =>
         iter.toVector
-          .sortBy(_.lift)(Ordering.Double.reverse)
+          .sortBy(_.confidence)(Ordering.Double.reverse)
           .take(ap.maxNumRulesPerCond)
         )
       .collectAsMap.toMap