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我正在嘗試在scala中定義一個函數,以使用Spark對其進行迭代。 這裏是我的代碼:函數參數中的RDD [Vector]的錯誤
import org.apache.spark.{SparkConf, SparkContext}
import org.apache.spark.sql.SQLContext
import org.apache.spark.ml.{Pipeline, PipelineModel}
import org.apache.spark.ml.clustering.KMeans
import org.apache.spark.mllib.linalg.Vectors
import org.apache.spark.ml.feature.VectorIndexer
import org.apache.spark.ml.feature.VectorAssembler
import org.apache.spark.rdd._
val assembler = new VectorAssembler()
.setInputCols(Array("feature1", "feature2", "feature3"))
.setOutputCol("features")
val assembled = assembler.transform(df)
// measures the average distance to centroid, for a model built with a given k.
def clusteringScore(data: RDD[Vector],k:Int) = {
val kmeans = new KMeans()
.setK(k)
.setFeaturesCol("features")
.setPredictionCol("prediction")
val model = kmeans.fit(data)
val WSSSE = model.computeCost(data) println(s"Within Set Sum of Squared Errors = $WSSSE")
}
(5 to 40 by 5).map(k => (k, clusteringScore(assembled, k))).
foreach(println)
有了這個代碼,我得到這個錯誤:
type Vector takes type parameters
我不知道是什麼意思這個錯誤...