scala-sparkML学习笔记：模型评估

scala-sparkML中模型评估标准比较全面， 基本不用像pyspark-ml学习笔记：模型评估使用其他方法。

// 二分类下的模型评估。
// Precision by threshold
val precision = metrics.precisionByThreshold
precision.foreach { case (t, p) =>
  println(s"Threshold: $t, Precision: $p")
}

// Recall by threshold
val recall = metrics.recallByThreshold
recall.foreach { case (t, r) =>
  println(s"Threshold: $t, Recall: $r")
}

// Precision-Recall Curve
val PRC = metrics.pr

// F-measure
val f1Score = metrics.fMeasureByThreshold
f1Score.foreach { case (t, f) =>
  println(s"Threshold: $t, F-score: $f, Beta = 1")
}

val beta = 0.5
val fScore = metrics.f