如何将数组列表转换为多维数组 [英] How to convert list of arrays into a multidimensional array

问题描述

我需要将下面的集合转换成double[,]:

I need to convert the following collection into double[,]:

 var ret = new List<double[]>();

列表中的所有数组都具有相同的长度.最简单的方法 ret.ToArray() 产生 double[][]，这不是我想要的.当然，我可以手动创建一个新数组，然后循环复制数字，但有没有更优雅的方法?

All the arrays in the list have the same length. The simplest approach, ret.ToArray(), produces double[][], which is not what I want. Of course, I can create a new array manually, and copy numbers over in a loop, but is there a more elegant way?

我的库是从另一种语言 Mathematica 调用的，该语言不是在 .Net 中开发的.我不认为该语言可以使用锯齿状数组.我必须返回一个多维数组.

my library is invoked from a different language, Mathematica, which has not been developed in .Net. I don't think that language can utilize jagged arrays. I do have to return a multidimensional array.

推荐答案

我不相信框架中内置了任何东西可以做到这一点 - 即使 Array.Copy 在这种情况下也失败了.但是，通过循环编写代码很容易:

I don't believe there's anything built into the framework to do this - even Array.Copy fails in this case. However, it's easy to write the code to do it by looping:

using System;
using System.Collections.Generic;

class Test
{
    static void Main()
    {
        List<int[]> list = new List<int[]>
        {
            new[] { 1, 2, 3 },
            new[] { 4, 5, 6 },
        };

        int[,] array = CreateRectangularArray(list);
        foreach (int x in array)
        {
            Console.WriteLine(x); // 1, 2, 3, 4, 5, 6
        }
        Console.WriteLine(array[1, 2]); // 6
    }

    static T[,] CreateRectangularArray<T>(IList<T[]> arrays)
    {
        // TODO: Validation and special-casing for arrays.Count == 0
        int minorLength = arrays[0].Length;
        T[,] ret = new T[arrays.Count, minorLength];
        for (int i = 0; i < arrays.Count; i++)
        {
            var array = arrays[i];
            if (array.Length != minorLength)
            {
                throw new ArgumentException
                    ("All arrays must be the same length");
            }
            for (int j = 0; j < minorLength; j++)
            {
                ret[i, j] = array[j];
            }
        }
        return ret;
    }

}

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