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实验六 Spark机器学习库MLlib编程初级实践

1 实验目的

(1)通过实验掌握基本的MLLib编程方法;

(2)掌握用MLLib解决一些常见的数据分析问题,包括数据导入、成分分析和分类和预测等。

2 实验平台

操作系统:Ubuntu16.04及以上

JDK版本:1.8或以上版本

Spark版本:3.4.0

数据集:下载Adult数据集(http://archive.ics.uci.edu/ml/datasets/Adult),该数据集也可以直接到本教程官网的“下载专区”的“数据集”中下载。数据从美国1994年人口普查数据库抽取而来,可用来预测居民收入是否超过50K$/year。该数据集类变量为年收入是否超过50k$,属性变量包含年龄、工种、学历、职业、人种等重要信息,值得一提的是,14个属性变量中有7个类别型变量。

3 实验要求

******1.**数据导入

从文件中导入数据,并转化为DataFrame。

*2.进行主成分分析(PCA*****

对6个连续型的数值型变量进行主成分分析。PCA(主成分分析)是通过正交变换把一组相关变量的观测值转化成一组线性无关的变量值,即主成分的一种方法。PCA通过使用主成分把特征向量投影到低维空间,实现对特征向量的降维。请通过setK()方法将主成分数量设置为3,把连续型的特征向量转化成一个3维的主成分。

*3.训练分类模型并预测居民收入*

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。

******4.**超参数调优

利用CrossValidator确定最优的参数,包括最优主成分PCA的维数、分类器自身的参数等。

4 实验内容和步骤(操作结果要附图)

从文件中导入数据,并转化为DataFrame。

在进行数据导入前,要先对所下载的adult数据集进行预处理

//导入需要的包

import org.apache.spark.ml.feature.PCA

import org.apache.spark.sql.Row

import org.apache.spark.ml.linalg.{Vector,Vectors}

import org.apache.spark.ml.evaluation.MulticlassClassificationEvaluator

import org.apache.spark.ml.{Pipeline,PipelineModel}

import org.apache.spark.ml.feature.{IndexToString, StringIndexer, VectorIndexer,HashingTF, Tokenizer}

import org.apache.spark.ml.classification.LogisticRegression

import org.apache.spark.ml.classification.LogisticRegressionModel

import org.apache.spark.ml.classification.{BinaryLogisticRegressionSummary, LogisticRegression}

import org.apache.spark.sql.functions;

//获取训练集测试集(需要对测试集进行一下处理,adult.data.txt的标签是>50K和<=50K,而adult.test.txt的标签是>50K.和<=50K.,这里是把adult.test.txt标签中的“.”去掉了)

import spark.implicits._

scala> import spark.implicits._

import spark.implicits._

 case class Adult(features: org.apache.spark.ml.linalg.Vector, label: String)

scala> case class Adult(features: org.apache.spark.ml.linalg.Vector, label: String)

defined class Adult

(路径要存在HDFS上,记得打开Haadoop)

val df = sc.textFile("hdfs://localhost:9000/user/hadoop/adult.data.txt").map(_.split(",")).map(p => Adult(Vectors.dense(p(0).toDouble,p(2).toDouble,p(4).toDouble, p(10).toDouble, p(11).toDouble, p(12).toDouble), p(14).toString())).toDF()

scala> val df = sc.textFile("hdfs://localhost:9000/user/hadoop/adult.data.txt").map(_.split(",")).map(p => Adult(Vectors.dense(p(0).toDouble,p(2).toDouble,p(4).toDouble, p(10).toDouble, p(11).toDouble, p(12).toDouble), p(14).toString())).toDF()

val test = sc.textFile("hdfs://localhost:9000/user/hadoop/adult.test.txt").map(_.split(",")).map(p => Adult(Vectors.dense(p(0).toDouble,p(2).toDouble,p(4).toDouble, p(10).toDouble, p(11).toDouble, p(12).toDouble), p(14).toString())).toDF()

scala> val test = sc.textFile("hdfs://localhost:9000/user/hadoop/adult.test.txt").map(_.split(",")).map(p => Adult(Vectors.dense(p(0).toDouble,p(2).toDouble,p(4).toDouble, p(10).toDouble, p(11).toDouble, p(12).toDouble), p(14).toString())).toDF()

对6个连续型的数值型变量进行主成分分析。

PCA(主成分分析)是通过正交变换把一组相关变量的观测值转化成一组线性无关的变量值,即主成分的一种方法。

PCA通过使用主成分把特征向量投影到低维空间,实现对特征向量的降维。

通过setK()方法将主成分数量设置为3,把连续型的特征向量转化成一个3维的主成分。

构建PCA模型,并通过训练集进行主成分分解,然后分别应用到训练集和测试集

al pca = new PCA().setInputCol("features").setOutputCol("pcaFeatures").setK(3).fit(df)

scala> val pca = new PCA().setInputCol("features").setOutputCol("pcaFeatures").setK(3).fit(df)

17/09/07 17:43:04 WARN BLAS: Failed to load implementation from: com.github.fommil.netlib.NativeSystemBLAS

17/09/07 17:43:04 WARN BLAS: Failed to load implementation from: com.github.fommil.netlib.NativeRefBLAS

17/09/07 17:43:04 WARN LAPACK: Failed to load implementation from: com.github.fommil.netlib.NativeSystemLAPACK

17/09/07 17:43:04 WARN LAPACK: Failed to load implementation from: com.github.fommil.netlib.NativeRefLAPACK

pca: org.apache.spark.ml.feature.PCAModel = pca_22d742dc5c91

 val result = pca.transform(df)

scala> val result = pca.transform(df)

result: org.apache.spark.sql.DataFrame = [features: vector, label: string ... 1 more field]

 val testdata = pca.transform(test)

scala> val testdata = pca.transform(test)

testdata: org.apache.spark.sql.DataFrame = [features: vector, label: string ... 1 more field]

result.show(false)

scala> result.show(false)

+------------------------------------+------+-----------------------------------------------------------+

|features |label |pcaFeatures |

+------------------------------------+------+-----------------------------------------------------------+

|[39.0,77516.0,13.0,2174.0,0.0,40.0] | <=50K|[77516.0654328193,-2171.6489938846585,-6.9463604765987625] |

|[50.0,83311.0,13.0,0.0,0.0,13.0] | <=50K|[83310.99935595776,2.526033892790795,-3.38870240867987] |

|[38.0,215646.0,9.0,0.0,0.0,40.0] | <=50K|[215645.99925048646,6.551842584546877,-8.584953969073675] |

|[53.0,234721.0,7.0,0.0,0.0,40.0] | <=50K|[234720.99907961802,7.130299808613842,-9.360179790809983] |

|[28.0,338409.0,13.0,0.0,0.0,40.0] | <=50K|[338408.9991883054,10.289249842810678,-13.36825187163136] |

|[37.0,284582.0,14.0,0.0,0.0,40.0] | <=50K|[284581.9991669545,8.649756033705797,-11.281731333793557] |

|[49.0,160187.0,5.0,0.0,0.0,16.0] | <=50K|[160186.99926937037,4.86575372118689,-6.394299355794958] |

|[52.0,209642.0,9.0,0.0,0.0,45.0] | >50K |[209641.99910851708,6.366453450443119,-8.38705558572268] |

|[31.0,45781.0,14.0,14084.0,0.0,50.0]| >50K |[45781.42721110636,-14082.596953729324,-26.3035091053821] |

|[42.0,159449.0,13.0,5178.0,0.0,40.0]| >50K |[159449.15652342222,-5173.151337268416,-15.351831002507415]|

|[37.0,280464.0,10.0,0.0,0.0,80.0] | >50K |[280463.9990886109,8.519356755954709,-11.188000533447731] |

|[30.0,141297.0,13.0,0.0,0.0,40.0] | >50K |[141296.99942061215,4.2900981666986855,-5.663113262632686] |

|[23.0,122272.0,13.0,0.0,0.0,30.0] | <=50K|[122271.9995362372,3.7134109235547164,-4.887549331279983] |

|[32.0,205019.0,12.0,0.0,0.0,50.0] | <=50K|[205018.99929839539,6.227844686207229,-8.176186180265503] |

|[40.0,121772.0,11.0,0.0,0.0,40.0] | >50K |[121771.99934864056,3.6945287780540603,-4.918583567278704] |

|[34.0,245487.0,4.0,0.0,0.0,45.0] | <=50K|[245486.99924622496,7.4601494174606815,-9.75000324288002] |

|[25.0,176756.0,9.0,0.0,0.0,35.0] | <=50K|[176755.9994399727,5.370793765347799,-7.029037217537133] |

|[32.0,186824.0,9.0,0.0,0.0,40.0] | <=50K|[186823.99934678187,5.675541056422981,-7.445605003141515] |

|[38.0,28887.0,7.0,0.0,0.0,50.0] | <=50K|[28886.99946951148,0.8668334219437271,-1.2969921640115318] |

|[43.0,292175.0,14.0,0.0,0.0,45.0] | >50K |[292174.9990868344,8.87932321571431,-11.599483225618247] |

+------------------------------------+------+-----------------------------------------------------------+

only showing top 20 rows

 testdata.show(false)

scala> testdata.show(false)

+------------------------------------+-------+-----------------------------------------------------------+

|features |label |pcaFeatures |

+------------------------------------+-------+-----------------------------------------------------------+

|[25.0,226802.0,7.0,0.0,0.0,40.0] | <=50K.|[226801.99936708904,6.893313042325555,-8.993983821758796] |

|[38.0,89814.0,9.0,0.0,0.0,50.0] | <=50K.|[89813.99938947687,2.7209873244764906,-3.6809508659704675] |

|[28.0,336951.0,12.0,0.0,0.0,40.0] | >50K. |[336950.99919122306,10.244920104026273,-13.310695651856003]|

|[44.0,160323.0,10.0,7688.0,0.0,40.0]| >50K. |[160323.23272903427,-7683.121090489607,-19.729118648470976]|

|[18.0,103497.0,10.0,0.0,0.0,30.0] | <=50K.|[103496.99961293535,3.142862309150963,-4.141563083946321] |

|[34.0,198693.0,6.0,0.0,0.0,30.0] | <=50K.|[198692.9993369046,6.03791177465338,-7.894879761309586] |

|[29.0,227026.0,9.0,0.0,0.0,40.0] | <=50K.|[227025.99932507655,6.899470708670979,-9.011878890810314] |

|[63.0,104626.0,15.0,3103.0,0.0,32.0]| >50K. |[104626.09338764261,-3099.8250060692035,-9.648800672052692]|

|[24.0,369667.0,10.0,0.0,0.0,40.0] | <=50K.|[369666.99919110356,11.241251385609905,-14.581104454203475]|

|[55.0,104996.0,4.0,0.0,0.0,10.0] | <=50K.|[104995.9992947583,3.186050789405019,-4.236895975019816] |

|[65.0,184454.0,9.0,6418.0,0.0,40.0] | >50K. |[184454.1939240066,-6412.391589847388,-18.518448307264528] |

|[36.0,212465.0,13.0,0.0,0.0,40.0] | <=50K.|[212464.99927015396,6.455148844458399,-8.458640605561254] |

|[26.0,82091.0,9.0,0.0,0.0,39.0] | <=50K.|[82090.999542367,2.489111409624171,-3.335593188553175] |

|[58.0,299831.0,9.0,0.0,0.0,35.0] | <=50K.|[299830.9989556855,9.111696151562521,-11.909141441347733] |

|[48.0,279724.0,9.0,3103.0,0.0,48.0] | >50K. |[279724.0932834471,-3094.495799296398,-16.491321474159864] |

|[43.0,346189.0,14.0,0.0,0.0,50.0] | >50K. |[346188.9990067698,10.522518314317386,-13.720686643182727] |

|[20.0,444554.0,10.0,0.0,0.0,25.0] | <=50K.|[444553.9991678726,13.52288689604709,-17.47586621453762] |

|[43.0,128354.0,9.0,0.0,0.0,30.0] | <=50K.|[128353.99933456781,3.895809826834201,-5.163630508998832] |

|[37.0,60548.0,9.0,0.0,0.0,20.0] | <=50K.|[60547.99950268136,1.834388499828796,-2.482228457083787] |

|[40.0,85019.0,16.0,0.0,0.0,45.0] | >50K. |[85018.99937940767,2.5751267063691055,-3.4924978737087193] |

+------------------------------------+-------+-----------------------------------------------------------+

only showing top 20 rows

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。

训练逻辑斯蒂回归模型,并进行测试,得到预测准确率

scala> val labelIndexer = new StringIndexer().setInputCol("label").setOutputCol("indexedLabel").fit(result)

labelIndexer: org.apache.spark.ml.feature.StringIndexerModel = strIdx_6721796011c5

scala> labelIndexer.labels.foreach(println)

<=50K

50K

val featureIndexer = new VectorIndexer().setInputCol("pcaFeatures").setOutputCol("indexedFeatures").fit(result)

scala> val featureIndexer = new VectorIndexer().setInputCol("pcaFeatures").setOutputCol("indexedFeatures").fit(result)

featureIndexer: org.apache.spark.ml.feature.VectorIndexerModel = vecIdx_7b6672933fc3

scala> println(featureIndexer.numFeatures)

3

 val labelConverter = new IndexToString().setInputCol("prediction").setOutputCol("predictedLabel").setLabels(labelIndexer.labels)

scala> val labelConverter = new IndexToString().setInputCol("prediction").setOutputCol("predictedLabel").setLabels(labelIndexer.labels)

labelConverter: org.apache.spark.ml.feature.IndexToString = idxToStr_d0c9321aaaa9

 val lr = new LogisticRegression().setLabelCol("indexedLabel").setFeaturesCol("indexedFeatures").setMaxIter(100)

scala> val lr = new LogisticRegression().setLabelCol("indexedLabel").setFeaturesCol("indexedFeatures").setMaxIter(100)

lr: org.apache.spark.ml.classification.LogisticRegression = logreg_06812b41b118

val lrPipeline = new Pipeline().setStages(Array(labelIndexer, featureIndexer, lr, labelConverter))

scala> val lrPipeline = new Pipeline().setStages(Array(labelIndexer, featureIndexer, lr, labelConverter))

lrPipeline: org.apache.spark.ml.Pipeline = pipeline_b6b87b6e8cd5

val lrPipelineModel = lrPipeline.fit(result)

scala> val lrPipelineModel = lrPipeline.fit(result)

lrPipelineModel: org.apache.spark.ml.PipelineModel = pipeline_b6b87b6e8cd5

scala> val lrModel = lrPipelineModel.stages(2).asInstanceOf[LogisticRegressionModel]

lrModel: org.apache.spark.ml.classification.LogisticRegressionModel = logreg_06812b41b118

scala> println("Coefficients: " + lrModel.coefficientMatrix+"Intercept: "+lrModel.interceptVector+"numClasses: "+lrModel.numClasses+"numFeatures: "+lrModel.numFeatures)

Coefficients: -1.9828586428133616E-7 -3.5090924715811705E-4 -8.451506276498941E-4 Intercept: [-1.4525982557843347]numClasses: 2numFeatures: 3

val lrPredictions = lrPipelineModel.transform(testdata)

scala> val lrPredictions = lrPipelineModel.transform(testdata)

lrPredictions: org.apache.spark.sql.DataFrame = [features: vector, label: string ... 7 more fields]

 val evaluator = new MulticlassClassificationEvaluator().setLabelCol("indexedLabel").setPredictionCol("prediction")

scala> val evaluator = new MulticlassClassificationEvaluator().setLabelCol("indexedLabel").setPredictionCol("prediction")

evaluator: org.apache.spark.ml.evaluation.MulticlassClassificationEvaluator = mcEval_38ac5c14fa2a

val lrAccuracy = evaluator.evaluate(lrPredictions)

scala> val lrAccuracy = evaluator.evaluate(lrPredictions)

lrAccuracy: Double = 0.7764235163053484

println("Test Error = " + (1.0 - lrAccuracy))

scala> println("Test Error = " + (1.0 - lrAccuracy))

Test Error = 0.22357648369465155

利用CrossValidator确定最优的参数,包括最优主成分PCA的维数、分类器自身的参数等。

import org.apache.spark.ml.feature.PCAModel
import org.apache.spark.ml.tuning.{ParamGridBuilder,CrossValidator}

scala> import org.apache.spark.ml.feature.PCAModel

scala> import org.apache.spark.ml.tuning.{ParamGridBuilder,CrossValidator}

val pca = new PCA().setInputCol("features").setOutputCol("pcaFeatures")

scala> val pca = new PCA().setInputCol("features").setOutputCol("pcaFeatures")

pca: org.apache.spark.ml.feature.PCA = pca_b11b53a1002b

 val labelIndexer = new StringIndexer().setInputCol("label").setOutputCol("indexedLabel").fit(df)

scala> val labelIndexer = new StringIndexer().setInputCol("label").setOutputCol("indexedLabel").fit(df)

labelIndexer: org.apache.spark.ml.feature.StringIndexerModel = strIdx_f2a42d5e19c9

 val featureIndexer = new VectorIndexer().setInputCol("pcaFeatures").setOutputCol("indexedFeatures")

scala> val featureIndexer = new VectorIndexer().setInputCol("pcaFeatures").setOutputCol("indexedFeatures")

featureIndexer: org.apache.spark.ml.feature.VectorIndexer = vecIdx_0f9f0344fcfd

 val labelConverter = new IndexToString().setInputCol("prediction").setOutputCol("predictedLabel").setLabels(labelIndexer.labels)

scala> val labelConverter = new IndexToString().setInputCol("prediction").setOutputCol("predictedLabel").setLabels(labelIndexer.labels)

labelConverter: org.apache.spark.ml.feature.IndexToString = idxToStr_74967420c4ea

 val lr = new LogisticRegression().setLabelCol("indexedLabel").setFeaturesCol("indexedFeatures").setMaxIter(100)

scala> val lr = new LogisticRegression().setLabelCol("indexedLabel").setFeaturesCol("indexedFeatures").setMaxIter(100)

lr: org.apache.spark.ml.classification.LogisticRegression = logreg_3a643c15517d

val lrPipeline = new Pipeline().setStages(Array(pca, labelIndexer, featureIndexer, lr, labelConverter))

scala> val lrPipeline = new Pipeline().setStages(Array(pca, labelIndexer, featureIndexer, lr, labelConverter))

lrPipeline: org.apache.spark.ml.Pipeline = pipeline_4ff414fedeed

val paramGrid = new ParamGridBuilder().addGrid(pca.k, Array(1,2,3,4,5,6)).addGrid(lr.elasticNetParam, Array(0.2,0.8)).addGrid(lr.regParam, Array(0.01, 0.1, 0.5)).build()

scala> val paramGrid = new ParamGridBuilder().addGrid(pca.k, Array(1,2,3,4,5,6)).addGrid(lr.elasticNetParam, Array(0.2,0.8)).addGrid(lr.regParam, Array(0.01, 0.1, 0.5)).build()

paramGrid: Array[org.apache.spark.ml.param.ParamMap] =

Array({

    logreg_3a643c15517d-elasticNetParam: 0.2,

    pca_b11b53a1002b-k: 1,

    logreg_3a643c15517d-regParam: 0.01

}, {

    logreg_3a643c15517d-elasticNetParam: 0.2,

    pca_b11b53a1002b-k: 2,

    logreg_3a643c15517d-regParam: 0.01

}, {

    logreg_3a643c15517d-elasticNetParam: 0.2,

    pca_b11b53a1002b-k: 3,

    logreg_3a643c15517d-regParam: 0.01

}, {

    logreg_3a643c15517d-elasticNetParam: 0.2,

    pca_b11b53a1002b-k: 4,

    logreg_3a643c15517d-regParam: 0.01

}, {

    logreg_3a643c15517d-elasticNetParam: 0.2,

    pca_b11b53a1002b-k: 5,

    logreg_3a643c15517d-regParam: 0.01

}, {

    logreg_3a643c15517d-elasticNetParam: 0.2,

    pca_b11b53a1002b-k: 6,

    logreg_3a643c15517d-regParam: 0.01

}, {

    logreg_3a643c15517d-elasticNetParam: 0.2,

    pca_b11b53a1002...
val cv = new CrossValidator().setEstimator(lrPipeline).setEvaluator(new MulticlassClassificationEvaluator().setLabelCol("indexedLabel").setPredictionCol("prediction")).setEstimatorParamMaps(paramGrid).setNumFolds(3)

scala> val cv = new CrossValidator().setEstimator(lrPipeline).setEvaluator(new MulticlassClassificationEvaluator().setLabelCol("indexedLabel").setPredictionCol("prediction")).setEstimatorParamMaps(paramGrid).setNumFolds(3)

cv: org.apache.spark.ml.tuning.CrossValidator = cv_ae1c8fdde36b

val cvModel = cv.fit(df)

scala> val cvModel = cv.fit(df)

cvModel: org.apache.spark.ml.tuning.CrossValidatorModel = cv_ae1c8fdde36b

 val lrPredictions=cvModel.transform(test)

scala> val lrPredictions=cvModel.transform(test)

lrPredictions: org.apache.spark.sql.DataFrame = [features: vector, label: string ... 7 more fields]

val evaluator = new MulticlassClassificationEvaluator().setLabelCol("indexedLabel").setPredictionCol("prediction")

scala> val evaluator = new MulticlassClassificationEvaluator().setLabelCol("indexedLabel").setPredictionCol("prediction")

evaluator: org.apache.spark.ml.evaluation.MulticlassClassificationEvaluator = mcEval_c6a4b78effe0

val lrAccuracy = evaluator.evaluate(lrPredictions)

scala> val lrAccuracy = evaluator.evaluate(lrPredictions)

lrAccuracy: Double = 0.7833268290041506

println("准确率为"+lrAccuracy)

scala> println("准确率为"+lrAccuracy)

准确率为0.7833268290041506

scala> val bestModel= cvModel.bestModel.asInstanceOf[PipelineModel]

bestModel: org.apache.spark.ml.PipelineModel = pipeline_4ff414fedeed

scala> val lrModel = bestModel.stages(3).asInstanceOf[LogisticRegressionModel]

lrModel: org.apache.spark.ml.classification.LogisticRegressionModel = logreg_3a643c15517d

scala> println("Coefficients: " + lrModel.coefficientMatrix + "Intercept: "+lrModel.interceptVector+ "numClasses: "+lrModel.numClasses+"numFeatures: "+lrModel.numFeatures)

Coefficients: -1.5003517160303808E-7 -1.6893365468787863E-4 ... (6 total)Intercept: [-7.459195847829245]numClasses: 2numFeatures: 6

scala> val pcaModel = bestModel.stages(0).asInstanceOf[PCAModel]

pcaModel: org.apache.spark.ml.feature.PCAModel = pca_b11b53a1002b

 println("Primary Component: " + pcaModel.pc)

scala> println("Primary Component: " + pcaModel.pc)

Primary Component: -9.905077142269292E-6 -1.435140700776355E-4 ... (6 total)

0.9999999987209459 3.0433787125958012E-5 ...

-1.0528384042028638E-6 -4.2722845240104086E-5 ...

3.036788110999389E-5 -0.9999984834627625 ...

-3.9138987702868906E-5 0.0017298954619051868 ...

-2.1955537150508903E-6 -1.3109584368381985E-4 ...

可以看出,PCA最优的维数是6。

5 实验总结


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