Span<T> and Slice? about numsharp

[Oceania2018]

@fdncred I've read this article, I realized that Span<T> is important to NumSharp's performance, we might have to give up the net472, only support .NET Core 2.1. That would bring best performance without coping memory. @dotChris90 Do you agree with that? We can still moving forward in current T[] way, I'm saying we would replace it with Span<T>. Keep this issue open.

[dotChris90]

@Oceania2018 I agree 100% that we need the Span and I see that the slicing and views could give us the best benefits than :D Means we slicing matrix to multiple vectors (as an example) and do operations on vectors - the matrix could be also updated if we using this nice "managed pointers" :D

[Oceania2018]

Only can be used in .NET Core 2.1, NumSharp is using .net standard 2.0. We will change TargetFrameworks if needed.
https://www.codemag.com/article/1807051/Introducing-.NET-Core-2.1-Flagship-Types-Span-T-and-Memory-T

[dotChris90]

@Oceania2018 @fdncred just for curiosity. Do u use at moment . NET CORE or Full?
I think at moment we 3 are the main workers at this repo and I really like the span if we e.g. Slice arrays or generate different views for the same arrays. I think it could be also great when parallel operations.

[Oceania2018]

Seem like just install System.Memory through NuGet, NumSharp will support Span<T>, we store all data in a 1-d array, acutally, we don't need slice any data. Span<T> looks great, agree with you. Everything could be tried and test. Appriciate.

[fdncred]

I used dotnet full i.e. net472 however, if we're going to make a numpy clone that as fast as the real numpy the only way to do it is either with p/invoke or span. I think the netstandard, full, and core are slowly merging into one framework. The future is definitely core. Even WinForms and Xaml/Wpf are being rewritten in dotnet core right now. It's scheduled for 3.0 release.

This bit of code was made me think of Span. The Skip and Take specifically.
https://github.com/Oceania2018/NumSharp/blob/4bbca14e07066aa4692c8df27dae0a097bdfb215/src/NumSharp/NdArray.cs#L109

The downside to dotnet core is that it brings a lot of baggage with it in the form of dozens of assemblies/dlls.

For now I would suggest doing something like this:

#if FULL
// do dotnet full stuff
#else
// do dotnet core stuff
#endif

[fdncred]

One other benefit with dotnet core is that it runs on Windows/Mac/Linux. It's designed to be cross-platform.

[dotChris90]

Totally agree. Honestly at moment try our code on windows 10 and a Linux MX (Debian base). It's simple awesome to see we can target multiple platforms.

And we targeting multiple languages. C#, F#, VB and I often try powershell.

Beside this there is the cool project peachpie which bring php to the dotnet world.

On top of this. There exist bindings for Matlab and python. We could use NumSharp in python lol

So it's cool time to be dotnet developer.

But I guess soon or later there will be a new dotnet standard and with this we get the span in all frameworks.

:)

[dotChris90]

@fdncred @Oceania2018 did you hear something like a NetStadard2.1 or 3.0?
The last Update I hear is that 2.0 is the latest standard.
If we know a new standard we could plan if changing the Standard can be done now, in some weeks or .... other date

[fdncred]

I have not heard of a new netstandard however i have heard of netcore3 which will include winforms and wpf cross platform.

[fdncred]

@dotChris90, @Oceania2018 Before moving forward with Span could you please test my latest push d1bed10? I've only been able to test with my MacBook and OSX. Tomorrow I should be able to get back on Visual Studio. I just want confirmation that you can build all and run all the tests and they all succeed.

This is from vscode on my mac.

[dotChris90]

@fdncred mine works fine. First it shows such red lines like on the image. But after build, test and restart all works fine. Idk why .... but as long as it works. all ok. but at moment just on Windows 10. Maybe tomorrow should try it again on Linux.

[fdncred]

@dotChris90 are you using vscode or Visual Studio on Win10?

[dotChris90]

@fdncred VS Code. Honestly spoken now got used to it and like it more lol. Except on razor stuff... In cshtml stuff it still need some little more improvement

[fdncred]

Committed first Span code with 01e2de1. Ideally NDArray's T[] Data would be a Span<T> Data but it's not allowed. So, we'll have to figure out how and where to use it best. It's benefit is speed and reduced memory allocations.

[dotChris90]

Ok glade to see everybody of us seems to agree go with 2.1 core lol.

OK cool to see there are first push with it👍

[fdncred]

If we're going to use Span I don't think there is any other choice. I don't think netstandard nor netfull support Span.

[dotChris90]

By the way net standard 2.1 has the span

[Oceania2018]

Hooray

[fdncred]

@dotChris90 Is it released yet? or do you know when it will be released?

[dotChris90]

hm did not find any concrete date and on https://github.com/dotnet/standard/milestone/3 it seems there still some progress. I am not sure when it will be released. But I am sure it is not yet released. :(

[fdncred]

We can also see some things it doesn't include here. I assumed there would be a preview but I don't see one. Maybe they're not that far yet.

[dotChris90]

Yes this is correct. But I say - Oceania2018 already changed the csproj - so all work. So it is not critical to change to 2.1 standard. ;) anyway - the first day it is released, we should change the csproj. ;)

[Oceania2018]