1.18总结

在主成分分析的基础上，采用逻辑斯蒂回归，或者决策树模型预测居民收入是否超过
50K；对 Test 数据集进行验证。

val labelIndexer = new
StringIndexer().setInputCol("label").setOutputCol("indexedLabel").fit(result)
labelIndexer.labels.foreach(println)
val featureIndexer = new
VectorIndexer().setInputCol("pcaFeatures").setOutputCol("indexedFeatures").fit(result)
println(featureIndexer.numFeatures)
val labelConverter = new
IndexToString().setInputCol("prediction").setOutputCol("predictedLabel").setLabels(labelIndexer.
labels)
val lr = new
LogisticRegression().setLabelCol("indexedLabel").setFeaturesCol("indexedFeatures").setMaxIter(
100)
val lrPipeline = new Pipeline().setStages(Array(labelIndexer, featureIndexer, lr,
labelConverter))
val lrPipelineModel = lrPipeline.fit(result)
val lrAccuracy = evaluator.evaluate(lrPredictions)
println("Test Error = " + (1.0 - lrAccuracy))