[lx3459683]

I benchmarked this recently. It comes in at 4-10x slower than cpython for random typical use cases on my machine, which is not too shabby at all. The author also states that numpy is slower than it should be due to lack of support for BLAS at this time.

The real impressive feat to me isn't hosting jupyter in the browser. It's access to a reasonably fast implementation of numpy in the browser which smokes native JS code for homogeneous array operations. I would love to see a minimalistic WASM implementation of numpy that can seamlessly interop with normal JS. Such a library would open up all sorts of possibilities that aren't currently feasible due to perf reasons.

[makmanalp]

I can't believe I'm saying this but it would be neat to have a browser native BLAS, or absent that perhaps cross-compiled to WASM from a RUST implementation or something! Makes me think of all the demos like the tensorflow playground (dunno if all that happens in the browser or not).

[TAForObvReasons]

People are working on the pure JS version of BLAS: https://github.com/jacobbogers/blasjs . Hopefully that work leads to best practices and a standard

[xtrapolate]

Numpy is fast thanks to having much of its code compiled as a native library.

They were purposefully working to reduce abstraction, since performance mattered from day one.

WASM is a huge step backwards in that regard. If you care about performance, just install Python on your box and "pip install numpy". Do you absolutely have to have it come in a browser now?

[singularity2001]

Interesting, how do you derive at "4-10x slower"?

Running the exported notebook here takes

time py3 python.py real 0m0.145s

chrome: load html: 2sec run html: 13sec!

That's not 10 times slower, but a 100 times slower!

Still good start.

[lootsauce]

I have used Weblas "GPU Powered BLAS for Browsers" for matrix multiply and it smokes! https://github.com/waylonflinn/weblas

[travisoneill1]

Did you use js typed arrays (e.g. Uint32Array) to benchmark large array operations or just Array?