关于FPGrowth.FreqItemset中的WrappedArray的处理方法

一般我们可以用如下代码使用FPGrowth

import org.apache.spark.ml.fpm.FPGrowth val dataset = spark.createDataset(Seq( "1 2 5", "1 2 3 5", "1 2") ).map(t => t.split(" ")).toDF("items") val fpgrowth = new FPGrowth().setItemsCol("items").setMinSupport(0.5).setMinConfidence(0.6) val model = fpgrowth.fit(dataset) // Display frequent itemsets. model.freqItemsets.show() // Display generated association rules. model.associationRules.show() // transform examines the input items against all the association rules and summarize the // consequents as prediction model.transform(dataset).show()

其中 FPGrowth.FreqItemset的返回类型为DataFrame("items"[Array], "freq"[Long]) 如果要对其进步一处理，可以先使用如下代码进行转换

import scala.collection.mutatble model.freqItemsets.map{row => (row.getAs[mutable.WrappedArray[String]](0).toSet,row.getLong(1)) }