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scalaapache-sparkvectorrow

row to vector in scala spark


I have a row that is obtained in the following way:

val row_name = df.collect()(i)

how can I convert this row to a type vector so that it can be passed to fromML() as follows ?

val vector_name=org.apache.spark.mllib.linalg.Vectors.fromML(row_name)

thanks in advance!


Solution

  • You can use vectorAssembler:

    import org.apache.spark.ml.linalg.Vector
    import org.apache.spark.mllib.linalg.Vectors
    import org.apache.spark.ml.feature.VectorAssembler
    
    val df = Seq((1,2),(3,4)).toDF("col1","col2")
    
    val va = new VectorAssembler().setInputCols(Array("col1","col2")).setOutputCol("vector")
    
    val row0 = va.transform(df).select("vector").collect()(0).getAs[Vector](0)
    
    val vector0 = Vectors.fromML(row0)
    // vector0: org.apache.spark.mllib.linalg.Vector = [1.0,2.0]