clearprop

2 tahun yang laludiscuss

I thought Rust was thread-safe and I don't see any "unsafe" blocks. What am I missing?

2 tahun yang laludiscuss

Indeed, updated: https://github.com/alrevuelta/myblog/commit/9fcc3dc84b1d9b66...

Thanks for the feedback.

2 tahun yang laludiscuss

Great feedback. I have updated the post using convolve instead. There is a huge difference convolve/naive. On the other hand, convolved is slower than the FFT as expected, but for greater than 3000 degree polynomials or so. See diff: https://github.com/alrevuelta/myblog/commit/9fcc3dc84b1d9b66...

clearprop

2 tahun yang laludiscuss

Thanks! In case it helps: * Multiplying two polynomials as taught in school is in reality a convolution. * "performing the convolution of two signals in the time domain is equivalent to multiplying them in the frequency domain" * FFT allows us to convert from time domain to frequency domain * We use FFT to convert our polynomial to frequency domain. * If we are now in the frequency domain, we just need to multiply. Faster than a convolution.

Does it clarify the missing step? Happy to update the post with what's missing.

clearprop

2 tahun yang laludiscuss

Thanks for the comment. That makes sense, since as you are saying, a base10 number can be expressed as a polynomial where x=10. Eg: 983 = 9x^2 + 8x + 3 aka [9, 8, 3]. Wondering how big the number has to be to make sense, and where this is used in practice.

Submissions

Designing Critical Systems. Airplanes, Medical Devices, and Blockchains

Using a Real Quantum Computer for Ethereum Keys

Ergodicity and Stationarity. Luck but Not for You

Convolutions, Fast Fourier Transform and polynomials (2022)

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