Multidimensional Array in constructor

[domtheluck]

Hi,

I wonder if it's could be possible to initialize a NDArray with a multi dimensional array without using FromMultiDimArray method and by avoiding memory copy?

I thinking about maybe using a unmanaged pointer or something like that.

Right now, this is blocking us to adopt NumSharp because the initialization cost is too high.

Thanks

[Nucs]

NDArray.FromMultiDimArray<T>(Array dotNetArray) uses np.array(arr) internally but it seems to call the wrong overload.

Replace the NDArray.FromMultiDimArray<T>(Array dotNetArray) call with np.array(arr, copy: false) (make sure not to pass an non-generic System.Array so the right overload will be called).

[Nucs]

It was fixed in the mentioned commit above and will be available in the next release. For now, let me know if using np.array has fixed the problem for you.

[domtheluck]

Thanks for the quick answer :)! I will try it tomorrow and let you know if it's working.

[domtheluck]

np.array is actually slower than NDArray.FromMultiDimArray: Stopwatch stopWatch1 = new Stopwatch(); Stopwatch stopWatch2 = new Stopwatch();

stopWatch1.Start(); NDArray data1 = np.array( inputData.Data as Array, false ); stopWatch1.Stop();

ElapsedMilliseconds: 81

stopWatch2.Start(); NDArray data2 = NDArray.FromMultiDimArray<Double>( inputData.Data as Array ); stopWatch2.Stop();

ElapsedMilliseconds: 57

inputData.Data: double[1, 1, 29600, 16]

[Nucs]

(make sure >>>> not <<<< to pass an non-generic System.Array so the right overload will be called).

You should not use System.Array. This sends you to the following overload:

public static NDArray array(NDArray nd, bool copy = false) => copy ? new NDArray(nd.Storage.Clone()) : new NDArray(nd.Storage);

Passing System.Array calls implicit cast to NDArray.

You should use one of these overloads:

I guarantee it will run in less than 5ms. I dare to say <1ms.

[domtheluck]

Sorry my bad ... :)!