如何在Scala中用99％的值替换高于99％的值

Question

我对Scala还是很陌生，来自R背景，发现很难进行一些循环活动来了解异常值并将其替换为99或1个百分位数 下面是查询

如果我具有以下数据框

val input_val = sc.parallelize(Seq(
          ("a", 5, 7, 9, 12, 13),
          ("b", 6, 4, 3, 20, 17),
          ("c", 4, 9, 4, 6 , 9),
          ("d", 1, 2, 6, 8 , 1),
          ("e",1  ,2, 3,  4, 6)
        )).toDF("ID", "var1", "var2", "var3", "var4", "var5")

     val Array(a1,a2) = input_val.stat.approxQuantile("var1",Array(0.01,0.99),0.0)

        val P1 = a1
        val P2 = a2

        println(a1)
        println(a2)

        val Array(a11,a22) = input_val.stat.approxQuantile("var2",Array(0.01,0.99),0.0)

        val P1_1 = a11
        val P2_1 = a22

        val Outlier_remover = input_val.withColumn("OutlierExc"+lit("var1"),when( input_val("var1") < P1,P1)
                                       .when(input_val("var1") > P2,P2)
                                       .otherwise(input_val("var1")))
                                        .withColumn("OutlierExc"+lit("var2"),when( input_val("var2") < P1_1,P1_1)
                                          .when(input_val("var2") > P2_1,P2_1)
                                            .otherwise(input_val("var2"))).show()

但是我需要对45列进行此操作，因为它们是动态实现的