使用scala查看Spark中相关矩阵的所有列

import org.apache.spark.SparkConf
import org.apache.spark.sql.SparkSession
import org.apache.spark.mllib.linalg.{Matrix, Matrices}

val conf = new SparkConf().setAppName("MatrixColumns").setMaster("local")
val spark = SparkSession.builder().config(conf).getOrCreate()

val matrixData = Array(
  1.0, 2.0, 3.0,
  4.0, 5.0, 6.0,
  7.0, 8.0, 9.0
)
val numRows = 3
val numCols = 3
val matrix: Matrix = Matrices.dense(numRows, numCols, matrixData)

val allColumns = (0 until matrix.numCols).map { colIndex =>
  matrix.colIter.map(_.apply(colIndex)).toArray
}

// 打印所有列
allColumns.foreach { column =>
  println(column.mkString(","))
}