如何像按位表示一样在数据帧中表示数据？

Question

我想用某种位表示法替换数据框中的值

id       val1  val1
first    2     4    
second   3     2
third    4     2

---

val rowsRdd: RDD[Row] = sc.parallelize(    
  Seq(
    Row("first", 2, 4),
    Row("second", 3, 2),
    Row("third", 4, 2)
  )
)
val schema = new StructType()
  .add(StructField("id", StringType, true))
  .add(StructField("val1", DoubleType, true))
  .add(StructField("val2", DoubleType, true))
val df = spark.createDataFrame(rowsRdd, schema)

我必须这样替换2,3,4数字

2-0,1,1,1 
3-0,0,1,1
4-0,0,0,1

我想得到

id      val1         val2    
first   2-0,1,1,1    4-0,0,0,1     
second  3-0,0,1,1    2-0,1,1,1
third   4-0,0,0,1    2-0,1,1,1