将LabeledPoint的RDD转换为DataFrame toDF()错误

import org.apache.spark.sql.{Row, SparkSession}
import org.apache.spark.mllib.regression.LabeledPoint

val spark = SparkSession.builder()
  .appName("LabeledPoint to DataFrame")
  .getOrCreate()

// 创建一个LabeledPoint的RDD
val labeledPointRDD = spark.sparkContext.parallelize(Seq(
  LabeledPoint(0.0, Array(1.0, 2.0, 3.0)),
  LabeledPoint(1.0, Array(4.0, 5.0, 6.0)),
  LabeledPoint(0.0, Array(7.0, 8.0, 9.0))
))

// 将LabeledPoint的RDD转换为RDD[Row]
val rowRDD = labeledPointRDD.map(lp => Row(lp.label, lp.features))

// 定义DataFrame的schema
val schema = spark.sqlContext.createDataFrame(rowRDD, StructType(Seq(
  StructField("label", DoubleType, nullable = false),
  StructField("features", ArrayType(DoubleType, containsNull = false), nullable = false)
)))

// 打印DataFrame的内容
schema.show()