我尝试对单个分类变量上有两列的数据框执行线性回归，将performance预测为device_class的函数：
df.select('performance','device_class').show(5,False)
+----------------+------------+
|performance |device_class|
+----------------+------------+
|35 |2 |
|35 |2 |
|35 |2 |
|25 |2 |
|5 |1 |
+----------------+------------+
only showing top 5 rows
df.select('performance','device_class').printSchema()
root
|-- performance: integer (nullable = true)
|-- device_class: integer (nullable = true)
from pyspark.ml.regression import LinearRegression
from pyspark.ml import Pipeline
from pyspark.ml.feature import *
numEncoder = OneHotEncoder(dropLast=False,inputCol="device_class",outputCol="dev_class_cat")
fAssembler = VectorAssembler(
inputCols=['dev_class_cat'],
outputCol='features')
lr = LinearRegression(maxIter=10, regParam=0.3, elasticNetParam=0.8,labelCol='performance',featuresCol='features')
pipeline = Pipeline(stages=[numEncoder,fAssembler])
modelTmp = pipeline.fit(df)
modelTmp = pipeline.fit(df)
tmp = modelTmp.transform(df).select('performance','dev_class_cat','features').show(5,False)
+----------------+-------------+-------------+
|performance |dev_class_cat|features |
+----------------+-------------+-------------+
|35 |(5,[2],[1.0])|(5,[2],[1.0])|
|35 |(5,[2],[1.0])|(5,[2],[1.0])|
|35 |(5,[2],[1.0])|(5,[2],[1.0])|
|25 |(5,[2],[1.0])|(5,[2],[1.0])|
|5 |(5,[1],[1.0])|(5,[1],[1.0])|
+----------------+-------------+-------------+
only showing top 5 rows
工作正常，到目前为止一切顺利。但是，如果我将回归添加到管道中：
pipeline = Pipeline(stages=[numEncoder,fAssembler,lr])
modelTmp = pipeline.fit(df)
我收到了这个错误：
Py4JJavaError: An error occurred while calling o2503.fit.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 19 in stage 188.0 failed 4 times, most recent failure: Lost task 19.3 in stage 188.0 (TID 375286, rs119.hadoop.pvt): scala.MatchError: [25,1.0,(5,[1],[1.0])] (of class org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema)
at org.apache.spark.ml.regression.LinearRegression$$anonfun$5.apply(LinearRegression.scala:200)
at org.apache.spark.ml.regression.LinearRegression$$anonfun$5.apply(LinearRegression.scala:200)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:409)
at org.apache.spark.storage.memory.MemoryStore.putIteratorAsValues(MemoryStore.scala:214)
at org.apache.spark.storage.BlockManager$$anonfun$doPutIterator$1.apply(BlockManager.scala:919)
at org.apache.spark.storage.BlockManager$$anonfun$doPutIterator$1.apply(BlockManager.scala:910)
at org.apache.spark.storage.BlockManager.doPut(BlockManager.scala:866)
at org.apache.spark.storage.BlockManager.doPutIterator(BlockManager.scala:910)
at org.apache.spark.storage.BlockManager.getOrElseUpdate(BlockManager.scala:668)
at org.apache.spark.rdd.RDD.getOrCompute(RDD.scala:330)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:281)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:79)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:47)
at org.apache.spark.scheduler.Task.run(Task.scala:85)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:274)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
实际上我收到了很多错误。我发现这个帖子MatchError while accessing vector column in Spark 2.0引发了类似的错误，但我没有使用任何mllib内容。也许稀疏矢量有问题？