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我正在使用Spark(1.5.2)DataFrames并尝试获取分层数据集。我的数据已经被准备向二元分类并且只有这两个值用于class
,1和0sampleBy返回非常偏斜的结果
val Array(trainingData, testData) = df.randomSplit(Array(0.7, 0.3))
val fractions: Map[Int, Double] = Map(1 -> 0.5, 0 -> 0.5)
val trainingData3 = trainingData.stat.sampleBy("class", fractions, new Random().nextLong)
println("Training True Class = " + trainingData3.where("class=1").count())
println("Training False Class = " + trainingData3.where("class=0").count())
在控制台我得到表示1类的不正确大大比的输出为0:
Training True Class = 799845
Training False Class = 32797260
您可能正在寻找此http://stackoverflow.com/a/32241887/3415409 – eliasah