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Evolution Strategies as a Scalable Alternative to Reinforcement Learning

blog.openai.com

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Re: Evolution Strategies as a Scalable Alternative to Reinforcement Learning

#21
post #15

"A Field Guide to Genetic Programming" ( https://www.amazon.com/Field-Guide-Genetic-Programming/dp/14... ) is one of the better books I've read on the matter (but I've yet to read anything by Koza). W. Langdon's webpage ( http://www0.cs.ucl.ac.uk/staff/W.Langdon/ ) has a lot of great information.

Evolution Strategies is not an example of Genetic Programming, and that book by Langdon doesn't cover anything directly relevant to the linked article.

You're right, I'm sorry.

Re: Evolution Strategies as a Scalable Alternative to Reinforcement Learning

#22

I feel like this is more an argument against the efficiency of flat (non-hierarchical, not model-based) Deep Reinforcement Learning than an argument for Genetic/Evolutionary Algorithms. As in, if you're not solving a task more efficiently than Evolutionary Algorithms or more difficult than they can handle, you're not doing something right. Similar to how Deep PCA and Deep Random Forests blew ConvNets out of the water…

Deep PCA: https://arxiv.org/abs/1404.3606 Deep Forest: https://arxiv.org/abs/1702.08835

I think this is the Deep Forest paper you meant:

http://www.cv-foundation.org/openaccess/content_iccv_2015/pa...

That's Deep Neural Decision Forests; they benchmark against MNIST and obtain state of the art results.

The other paper is about improving decision forests, although it also uses MNIST as a benchmark.

Apologies if I'm wrong and you did mean the Zhou & Feng paper.

Re: Evolution Strategies as a Scalable Alternative to Reinforcement Learning

#23
post #18

Reading the code; I dont get get: 1. How to model the different actions 2. Tie future awards to action at this timestep... Can anyone help with better nitty-gritty explanation ?

The example code inline in the article just illustrates the basic idea of Evolution Strategies (ES), not their new work in applying ES. The behavior of agents is determined by a "policy function". This function takes in inputs (e.g. what the agent sees) and outputs actions (e.g. what the agent does). The policy function has a set of internal parameters that determines the precise mapping from inputs to outputs. In th…

Very good sir ! Makes more sense now ! Thank you.

Re: Evolution Strategies as a Scalable Alternative to Reinforcement Learning

#24

Earlier quoted context omitted.

Deep PCA: https://arxiv.org/abs/1404.3606 Deep Forest: https://arxiv.org/abs/1702.08835

I think this is the Deep Forest paper you meant: http://www.cv-foundation.org/openaccess/content_iccv_2015/pa... That's Deep Neural Decision Forests; they benchmark against MNIST and obtain state of the art results. The other paper is about improving decision forests, although it also uses MNIST as a benchmark. Apologies if I'm wrong and you did mean the Zhou & Feng paper.

That one is good too!

Re: Evolution Strategies as a Scalable Alternative to Reinforcement Learning

#25
post #6

Earlier quoted context omitted.

Not sure where you're getting this from, but CNNs are definitely still state of the art on MNIST. Papers often cite outdated CNN numbers; in fact the best published CNN accuracy numbers are probably lower than they could be - vanilla MNIST for supervised learning is a pretty useless benchmark for computer vision researchers now.

My bad, I should have been more specific. The Deep PCA paper shows superior performance not on baseline MNIST, but on the MNIST variations. I also agree that vanilla MNIST is pretty useless for Computer Vision researches and was trying (awkwardly) to support that idea by showing how these other non Deep Learning techniques performed equally well.

The Deep PCA paper shows no such thing. They've cherry-picked bad CNN baselines. The red flag for me is that the "state of the art" methods they compare to achieve > 1% test error on vanilla MNIST, which is totally wrong since CNNs routinely achieve <0.5 % test error (even by the standards of 2014, when the paper was published).

Re: Evolution Strategies as a Scalable Alternative to Reinforcement Learning

#27
> we were able to solve one of the hardest MuJoCo tasks (a 3D humanoid) using 1,440 CPUs across 80 machines in only 10 minutes. As a comparison, in a typical setting 32 A3C workers on one machine would solve this task in about 10 hours.

So using 80 times more machines makes you 60 times faster (assuming those are the same machines) "while performing better on 23 games tested, and worse on 28"[0]?

[0] The paper for this blog post https://arxiv.org/pdf/1703.03864.pdf

Asynchronous advantage actor critic (A3C) https://arxiv.org/pdf/1602.01783.pdf

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