Problem in List<double[,]>

What is wrong with this (in C# 3.0):

List<double> x = new List<double> { 0.0330, -0.6463, 0.1226, -0.3304, 0.4764, -0.4159, 0.4209, -0.4070, -0.2090, -0.2718, -0.2240, -0.1275, -0.0810, 0.0349, -0.5067, 0.0094, -0.4404, -0.1212 };
List<double> y = new List<double> { 0.4807, -3.7070, -4.5582, -11.2126, -0.7733, 3.7269, 2.7672, 8.3333, 4.7023,0,0,0,0,0,0,0,0,0 };

List<double[,]> z = new List<double[,]>{x,y}; // this line

The error produced is:

Error: Argument '1': cannot convert from 'System.Collections.Generic.List<double>' to 'double[*,*]' 
开发者_如何学运维

Help needed.

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var z = new List<List<double>> { x, y };

However if you want to store your two lists in a twodimensional array ([,]) this is your anwser. You will have to convert it manually as shown there:

public static T[,] To2dArray(this List<List<T>> list)
{
    if (list.Count == 0 || list[0].Count == 0)
        throw new ArgumentException("The list must have non-zero dimensions.");

    var result = new T[list.Count, list[0].Count];
    for(int i = 0; i < list.Count; i++)
    {
        for(int j = 0; j < list.Count; j++)
        {
            if (list[i].Count != list[0].Count)
                throw new InvalidOperationException("The list cannot contain elements (lists) of different sizes.");
            result[i, j] = list[i][j];
        }
    }

    return result;
}

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The collection initializer for List<double[,]> expects elements of type double[,] (which is a two-dimensional array, similar to a matrix), but you're passing it x and y, which are of type List<double>, which means it's trying to add two lists of doubles as the elements of the new list.

If you're trying add coordinates to the list, then you need a structure of some sort to contain them. You could write your own or you could use System.Drawing.PointF.

---

double[,] defines a multidimensional array but you are specifying two Lists.

From your Initialization it looks like you are looking for something like

List<PointF> list = new List<PointF> { new PointF (0.0330F, 0.4807F), new PointF (-0.6463F, -3.7070F) };

---

Shouldn't it be:

List<List<double>,List<double>> z = new List<List<double>, List<double>>{x,y};

But I don't think that is really what you're after is it?

---

Are you after something like this?

        List<double> x = new List<double> { 0.0330, -0.6463, 0.1226, -0.3304, 0.4764, -0.4159, 0.4209, -0.4070, -0.2090, -0.2718, -0.2240, -0.1275, -0.0810, 0.0349, -0.5067, 0.0094, -0.4404, -0.1212 };
        List<double> y = new List<double> { 0.4807, -3.7070, -4.5582, -11.2126, -0.7733, 3.7269, 2.7672, 8.3333, 4.7023, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

        List<double[]> z = x.Select((x1, index) => new double[2] {x1, y[index]} ).ToList();

EDIT: changed my answer to join the lists on the index correctly instead of looking it up.