Array of structs to NDarray

[Laur-Ivan]

Hello!
I have somewhat of a weird question. I am using Numpy.NET with the Unity game engine. Most of it works fine, but I am trying to convert an Array of Vector3 to NDarray, but I had no success yet.
Since that's an Unity specific class, I get why it might not work. But might I define a struct as a wrapper and transform an array of structs to the NDarray? The struct would be very simple, holding three floats (x,y,z).

[henon]

Numpy always usees one dimensional arrays under the hood, in your case a float[]. With that you create your NDArray and then you reshape it to reflect your multi-dimensional data. Check out reshape documentation and try it on a python console to find out more.
Or you create the NDArray with a two dimensional float[,], but Numpy.NET will internally copy that into a 1D array again as you can see in the code of that constructor.

[Nucs]

If you would agree to store the values in a (n, 3) dimension where n is the number of items in the array and 3 is x,y,z in that order.
It seems that Vector3 answers to the constraint 'T : unmanaged' so it can be treated as binary data within unsafe code.
So I'm proposing something like that

struct Vector3 {
    public float x;
    public float y;
    public float z;
}

static unsafe void Main(string[] args) {
    Vector3[] myVectors = new Vector3[100];
    fixed (Vector3* ptr_vector = myVectors) {
        var nd = new Numpy.NDarray(new IntPtr(ptr_vector), (3 * myVectors.Length * sizeof(float)), np.float32);
        nd = nd.reshape(myVectors.Length, 3);
        //TODO: w/e i wanted to do with 'nd'
    }

    //do not use 'nd' outside the fixed block
}

If you are looking to use myVectors outside the fixed block then use GCHandle.Alloc(bytesBuffer, GCHandleType.Pinned).AddrOfPinnedObject to prevent GC from moving it and then use the same NDarray constructor.