以下代码在运行时报以下错误

val conf = new SparkConf().setAppName("NNtest").setMaster("local")
val sc = new SparkContext(conf)
Logger.getRootLogger.setLevel(Level.WARN)
///

val data_path = "/user/testdata/data1.txt"
val example =sc.textFile(data_path).cache()
val train_d1 = example.map {line =>
      val f1 = line.split("\t")
      val f = f1.map(f => f.toDouble)
      val id = f(0)
      val y = Array(f(1))
      val x = f.slice(2, f.length)
      (id, new BDM(1, y.length, y), new BDM(1, x.length, x))
    }
    val bdmy =train_d1.map(f =>f._2)
    val bdmx = train_d1.map(f =>f._3)
    val randsamp1 = BDM.horzcat(bdmy,bdmx)

运行以上代码报如下错误，请问是什么原因呢？

Error:(39, 36) Cannot prove that org.apache.spark.rdd.RDD[breeze.linalg.DenseMatrix[Double]] <:< breeze.linalg.Matrix[V].
val randsamp1 = BDM.horzcat(bdmy,bdmx)
^

这语法是有问题的吧。是nodejs么