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Discovering faster matrix multiplication algorithms with reinforcement learning

nature.com

31–40 of 116 posts

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#32
post #15

The big claim turns out to be a little overstated. The claim: > AlphaTensor’s algorithm improves on Strassen’s two-level algorithm for the first time, to our knowledge, since its discovery 50 years ago. reduces to: > AlphaTensor discovers algorithms that outperform the Strassen-square algorithm, which is a fast algorithm for large square matrices31,32. Although the discovered algorithm has the same theoretical comple…

This is not a correct summary of the results of the paper. First, you cut out the initial part of the sentence about improving on Strassen's two-level algorithm. Here is the complete sentence: > Particularly relevant is the case of 4 × 4 matrices in a finite field, where AlphaTensor’s algorithm improves on Strassen’s two-level algorithm for the first time, to our knowledge, since its discovery 50 years ago. That is,…

Isn’t multiplying two 4x4 matrices a finite problem? What does big O complexity mean in that case?

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#33
post #30

Earlier quoted context omitted.

This is not a correct summary of the results of the paper. First, you cut out the initial part of the sentence about improving on Strassen's two-level algorithm. Here is the complete sentence: > Particularly relevant is the case of 4 × 4 matrices in a finite field, where AlphaTensor’s algorithm improves on Strassen’s two-level algorithm for the first time, to our knowledge, since its discovery 50 years ago. That is,…

what, no, you have this all wrong. the complexity of multiplying two 4x4 matrices is clearly constant. the important thing about the constant, however, is that you can use this primitive on the block matrices recursively to possibly improve the asymptotic complexity. the complexity improvement in this paper is for arithmetic in Z_2 (modular arithmetic over single bits). in standard arithmetic, there is no asymptotic…

You are correct. I will edit.

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#34

I have a gut feeling that there is a faster way to compute logarithms going from least to most significant bit. How would I go about using ML to find it? [Edit] I think Feynman's algorithm might do it: "Consider the problem of finding the logarithm of a fractional number between 1 and 2. (The algorithm can be generalized without too much difficulty.) Feynman observed that any such number can be uniquely represented a…

note that this algorithm will no longer be good. for precisions up to roughly 1000 bits small tables combined with minimax polynomials are optimal and for higher precision, you want to use more complicated methods. if you're interested, the ARB library unlikely the currently fastest known methods.

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#35
post #17

Earlier quoted context omitted.

That's the DeepMind modus operandi- and why they publish in Nature. It's in their best interest to claim as much covered ground as possible so they can keep working towards their end-goal. But most people who read Nature already know that results in that journal are overhyped. You just have to apply a specific prior/translator when you read their papers.

This really is a depressingly true sentiment. Nature is both the most important publication but so often, the big shots publish overhyped stuff there that doesn't deserve it but get away with it since they are bigshots. Underscore here for another piece of evidence of the dysfunction in science.

I don't doubt the sentiment is true, but hasn't this kind of science always been this way? By that I mean authors inflating the importance of their work; everyone wants to be seen as having the biggest breakthroughs.

When I think of dysfunction in 'science' I usually think of unfalsifiable hypothesis, the repeatability crisis in Psychology, p-hacking in Medicine, misuse of statistical methods in Economics and other epistemic issues, but I don't think of exaggerations like this.

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#36
post #29
post #15

The big claim turns out to be a little overstated. The claim: > AlphaTensor’s algorithm improves on Strassen’s two-level algorithm for the first time, to our knowledge, since its discovery 50 years ago. reduces to: > AlphaTensor discovers algorithms that outperform the Strassen-square algorithm, which is a fast algorithm for large square matrices31,32. Although the discovered algorithm has the same theoretical comple…

On the other hand, real world performance is really the only useful metric for matrix multiplication. I don’t really care about the theoretical performance, or the number of operations. Not disagreeing with your take that the claim is grandiose, just pointing out that finding a generalizable way to automate the improvement of what is almost certainly the most important mathematical operation a computer can do is wort…

Surely theoretical improvement begets real world, especially in the context of highly specialised hardware.

It was with theoretical performance improvement that motivated the creation of SIMD and led to real world speed ups.

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#37

Earlier quoted context omitted.

This is not a correct summary of the results of the paper. First, you cut out the initial part of the sentence about improving on Strassen's two-level algorithm. Here is the complete sentence: > Particularly relevant is the case of 4 × 4 matrices in a finite field, where AlphaTensor’s algorithm improves on Strassen’s two-level algorithm for the first time, to our knowledge, since its discovery 50 years ago. That is,…

Isn’t multiplying two 4x4 matrices a finite problem? What does big O complexity mean in that case?

any fixed size multiplication algorithm has a corresponding general algorithm where you recursively divide a matrix into blocks and treat each block as an element. for any nxn algorithm that takes k multiplications, this yields a general algorithm with runtime n^log_n(k)

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#38
post #30

Earlier quoted context omitted.

This is not a correct summary of the results of the paper. First, you cut out the initial part of the sentence about improving on Strassen's two-level algorithm. Here is the complete sentence: > Particularly relevant is the case of 4 × 4 matrices in a finite field, where AlphaTensor’s algorithm improves on Strassen’s two-level algorithm for the first time, to our knowledge, since its discovery 50 years ago. That is,…

what, no, you have this all wrong. the complexity of multiplying two 4x4 matrices is clearly constant. the important thing about the constant, however, is that you can use this primitive on the block matrices recursively to possibly improve the asymptotic complexity. the complexity improvement in this paper is for arithmetic in Z_2 (modular arithmetic over single bits). in standard arithmetic, there is no asymptotic…

if you're in gf2 on a traditional cpu and care about wall clock time, i start to wonder how something like simd xors and parity would compare...

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#39

Earlier quoted context omitted.

This really is a depressingly true sentiment. Nature is both the most important publication but so often, the big shots publish overhyped stuff there that doesn't deserve it but get away with it since they are bigshots. Underscore here for another piece of evidence of the dysfunction in science.

I don't doubt the sentiment is true, but hasn't this kind of science always been this way? By that I mean authors inflating the importance of their work; everyone wants to be seen as having the biggest breakthroughs. When I think of dysfunction in 'science' I usually think of unfalsifiable hypothesis, the repeatability crisis in Psychology, p-hacking in Medicine, misuse of statistical methods in Economics and other e…

Scientists have long been self-promoters who desire that their theories become the dominant ones and they use many techniques to achieve this.

However, the trend towards maximizing the predicted outcomes of your research really took off during the human genomics project.

Re: Discovering faster matrix multiplication algorithms with reinforcement learning

#40

Earlier quoted context omitted.

This is not a correct summary of the results of the paper. First, you cut out the initial part of the sentence about improving on Strassen's two-level algorithm. Here is the complete sentence: > Particularly relevant is the case of 4 × 4 matrices in a finite field, where AlphaTensor’s algorithm improves on Strassen’s two-level algorithm for the first time, to our knowledge, since its discovery 50 years ago. That is,…

Isn’t multiplying two 4x4 matrices a finite problem? What does big O complexity mean in that case?

My understanding of this situation is that they found a way to multiply 4x4 matrices that requires fewer multiplications than Strassen's . This implies that that can generalize to a way to multiply n x n matrices with a better theoretical complexity than Strassen's algorithm.
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