converting type double[][] to float

Question

I have a function signature like:

static public double[][] G2Sweep(int row1, int row2, double[][] mtx)
{
    mtx = (float) mtx;
}

But I need to covert the double[][] matrix into float values. How is this done as the code can't explicitly convert it?

Answer 1

public static float[][] Convert(double[][] mtx)
{
    var floatMtx = new float[mtx.Length][];
    for (int i = 0; i < mtx.Length; i++)
    {
        floatMtx[i] = new float[mtx[i].Length];
        for (int j = 0; j < mtx[i].Length; j++)
            floatMtx[i][j] = (float)mtx[i][j];
    }
    return floatMtx;
}

Or:

public static float[][] Convert(double[][] mtx)
{
    return mtx.Select(i => i.Select(j => (float)j).ToArray()).ToArray();
}

Answer 2

No, you can't convert double to float in place, especially for arrays. You need to create copy with correct type.