Question

所以我正在学习Scala，并尝试创建一个基于数组的向量类，并创建一个加法和减法运算符来添加2个向量。这就是我到目前为止所做的。任何人都可以帮助弄清楚如何使它，以便当我添加到不同长度的向量时，它将“0”添加到具有较短长度的数组，以便它的长度等于具有更大长度的长度？就像向(1, 2)添加(1, 2, 3)一样，应该返回(2, 4, 3)

class Wektor(private val s: Array[Double]){
        class LengthNotEqualException(msg:String) extends Exception(msg)
        def get(index: Int):Double= s(index)
        def +(that: Wektor):Wektor=
          if(this.s.length != that.s.length)
                  throw new LengthNotEqualException("Wektory roznej dlugosci")
          else
          {
            val temp= new Array[Double](this.s.length)
            var i:Int= 0
                for(i <- 0 until this.s.length)
            {
                temp(i)= this.s(i) + that.get(i)
            }
            new Wektor(temp)    // zwraca nowy Wektor będący sumą danych wektorów
          }
        def -(that: Wektor):Wektor=
          if(this.s.length != that.s.length)
                  throw new LengthNotEqualException("Wektory roznej dlugosci")
          else
          {
            val temp= new Array[Double](this.s.length)
            var i= 0
                for(i <- 0 until this.s.length)
            {
                temp(i)= this.s(i) - that.get(i)
            }
            new Wektor(temp)    // zwraca nowy Wektor będący różnicą danych wektorów
          }
        def *+(that:Wektor):Double=
          if(this.s.length != that.s.length)
                  throw new LengthNotEqualException("Wektory roznej dlugosci")
          else
                {
                  var result:Double= 0
                  var i:Int = 0
                  for(i <- 0 until this.s.length)
                  {
                result= result + this.s(i) * that.get(i)
                  }
                  result        // zwracany iloczyn skalarny
                }
        override def toString():String={
          var result:String="Wektor: ["
          var i:Int= 0
          for(i <- 0 until this.s.length)
          {
                  result= result + this.s(i) + " "
          }
          result = result + "]"
          result        // zwracana wartosc
        }
}

val test= new Wektor(Array[Double](1, 2, 3,5))
val test2= new Wektor(Array[Double](2, 2, 2))
val suma= test + test2
val roznica= test - test2
val iloczyn= test *+ test2
println(suma)
println(roznica)
println(iloczyn)

Answer 1

像这样使用zipAll：

case class Wektor(inner: IndexedSeq[Double]) {
  def +(that: Wektor) =
    Wektor(this.inner.zipAll(that.inner, 0.0, 0.0).map{case (a, b) => a+b})
  def -(that: Wektor) =
    Wektor(this.inner.zipAll(that.inner, 0.0, 0.0).map{case (a, b) => a-b})
  def *+(that: Wektor) =
    this.inner.zipAll(that.inner, 1.0, 1.0).map{case (a, b) => a*b}.sum

  override def toString() = inner.mkString("Wektor: [", " ", "]")
}

val a = Wektor((1 to 5).map{_.toDouble})
// Wektor: [1.0 2.0 3.0 4.0 5.0]
val b = Wektor((1 to 3).map{_.toDouble})
// Wektor: [1.0 2.0 3.0]

a + b
// Wektor: [2.0 4.0 6.0 4.0 5.0]

a - b
// Wektor: [0.0 0.0 0.0 4.0 5.0]

a *+ b
// 23.0

在Scala中添加数组元素

1 个答案: