我不知道这是否是简单的方法，但我在下面包含了一些用于将嵌套元组转换为“二维”数组的代码。
首先，您需要一些样板来获取元组的大小以及将元组转换为[Array[Array[Double]]。我使用的一系列步骤是：
- 计算元组中的行数和列数
- 将嵌套元组变成单行数组
- 根据原始元组的大小重新调整数组的形状。
代码如下：
object Matrix {
/**
* Returns the size of a series of nested tuples.
*/
def productSize(t: Product): (Int, Int) = {
val a = t.productArity
val one = t.productElement(0)
if (one.isInstanceOf[Product]) {
val b = one.asInstanceOf[Product].productArity
(a, b)
}
else {
(1, a)
}
}
/**
* Flattens out a nested tuple and returns the contents as an iterator.
*/
def flattenProduct(t: Product): Iterator[Any] = t.productIterator.flatMap {
case p: Product => flattenProduct(p)
case x => Iterator(x)
}
/**
* Convert a nested tuple to a flattened row-oriented array.
* Usage is:
* {{{
* val t = ((1, 2, 3), (4, 5, 6))
* val a = Matrix.toArray(t)
* // a: Array[Double] = Array(1, 2, 3, 4, 5, 6)
* }}}
*
* @param t The tuple to convert to an array
*/
def toArray(t: Product): Array[Double] = flattenProduct(t).map(v =>
v match {
case c: Char => c.toDouble
case b: Byte => b.toDouble
case sh: Short => sh.toDouble
case i: Int => i.toDouble
case l: Long => l.toDouble
case f: Float => f.toDouble
case d: Double => d
case s: String => s.toDouble
case _ => Double.NaN
}
).toArray[Double]
def rowArrayTo2DArray[@specialized(Int, Long, Float, Double) A: Numeric](m: Int, n: Int,
rowArray: Array[A]) = {
require(rowArray.size == m * n)
val numeric = implicitly[Numeric[A]]
val newArray = Array.ofDim[Double](m, n)
for (i <- 0 until m; j <- 0 until n) {
val idx = i * n + j
newArray(i)(j) = numeric.toDouble(rowArray(idx))
}
newArray
}
/**
* Factory method for turning tuples into 2D arrays
*/
def apply(data: Product): Array[Array[Double]] = {
def size = productSize(data)
def array = toArray(data)
rowArrayTo2DArray(size._1, size._2, array)
}
}
现在要使用它，您只需执行以下操作：
val a = Matrix((1, 2, 3))
// a: Array[Array[Double]] = Array(Array(1.0, 2.0, 3.0))
val b = Matrix(((1, 2, 3), (4, 5, 6), (7, 8, 9)))
// b: Array[Array[Double]] = Array(Array(1.0, 2.0, 3.0),
// Array(4.0, 5.0, 6.0),
// Array(7.0, 8.0, 9.0))
val c = Matrix((1L, 2F, "3")) // Correctly handles mixed types
// c: Array[Array[Double]] = Array(Array(1.0, 2.0, 3.0))
val d = Matrix((1L, 2F, new java.util.Date())) // Non-numeric types convert to NaN
// d: Array[Array[Double]] = Array(Array(1.0, 2.0, NaN))
或者，如果您可以直接使用所需数组的大小和一维值数组调用 rowArrayTo2DArray：
val e = Matrix.rowArrayTo2DArray(1, 3, Array(1, 2, 3))
// e: Array[Array[Double]] = Array(Array(1.0, 2.0, 3.0))
val f = Matrix.rowArrayTo2DArray(3, 1, Array(1, 2, 3))
// f: Array[Array[Double]] = Array(Array(1.0), Array(2.0), Array(3.0))
val g = Matrix.rowArrayTo2DArray(3, 3, Array(1, 2, 3, 4, 5, 6, 7, 8, 9))
// g: Array[Array[Double]] = Array(Array(1.0, 2.0, 3.0),
// Array(4.0, 5.0, 6.0),
// Array(7.0, 8.0, 9.0))