neuroevolution | direct policy search deep reinforcement learning | Reinforcement Learning library
kandi X-RAY | neuroevolution Summary
kandi X-RAY | neuroevolution Summary
In direct policy search, the space of possible policies is searched directly. The agent does not attempt to model the transition dynamics of the environment, nor does it attempt to explicitly learn the value of different states or actions. Instead, it iteratively attempts to improve a parameterized policy. Direct policy search can be broken down into gradient-based methods, also known as policy gradient methods, and methods that do not rely on the gradient. Gradient-free methods include evolutionary algorithms. In this architecture, a convolutional neural network acts as a compressor for images perceived by an agent in its environment. It is defined in cnn.py and is trained by neuroevolution using train_cnn_ga.py. A recurrent neural network acts as a controller based on the output of the compressor. It is defined in rnn.py and is trained by neuroevolution using evolve_rnn_controller.py. A client that interacts with the environment must be defined and configured. The implementation is illustrated using a client that interacts with a customized version of the TORCS car racing simulation.
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- Run train_cnn
- Run the algorithm
- Updates model weights
- Plot fitness results
- Calculate the cnn output
- Runs the algorithm
- Evaluate a simplified population
- Estimate the average fitness for an individual
- Calculate fitness for a given set of feature vectors
- Calculate the RNN output of the input image
- Calculate RNN output
- Create a CNN
- Loads training set of images
neuroevolution Key Features
neuroevolution Examples and Code Snippets
Community Discussions
Trending Discussions on neuroevolution
QUESTION
I am trying to implement a NEAT (NeuroEvolution of Augmenting Topologies) algorithm in python, but after watching multiple guides and reading the original paper, I am left with one question. When a new node/neuron is created, is it then given a global number or a local number for its node genes?
The paper makes it sound like global number, but if that is the case there might be a mistake where the connection genes are different even though the connection is the same, if the order the node was created is different; However, if its local, the coming from and going to connection gene/the in out connection gene would be different depending on the NN. Hopefully it makes sense, if not let me know any help is greatly appreciated!
...ANSWER
Answered 2019-Aug-30 at 14:09I am not even sure "local number" even makes sense! The idea of the innovation numbers is precisely so that we can easily compare structures between different genomes.
When new nodes are created, normally one connection is split in two, adding a new node in the middle. This event is stored in a log, so if later on a different genome tries to create a new node by splitting the same connection, then the same innovation numbers are used.
Of course, in a bit of a roundabout way it is possible to create two genomes with the same structure but different innovation numbers. This is simply accepted.
I am adding a diagram with one such example, let me know if you were thinking about a different situation:
Note that some implementations have innovation numbers for both connections and nodes, while others only have such numbers for nodes, connections being fully described by the nodes they connect. In the first case it is also possible to end up having equivalent connections with different innovation numbers, but that is fine as well. There has been a bit of debate around this finer details, but in practice it seems the effects are minimal if anything.
QUESTION
I'm writing a library for genetic algorithms/neuroevolution. Currently, the program uses polymorphism to allow multiple types of genomes. So my code looks like this:
...ANSWER
Answered 2019-May-06 at 16:42Template might help your case better, but has other implication.
For example, your list cannot be heterogeneous in which genome type it contains. It must be all of the same type. If you need heterogenicity, then you'll have to implement some sort of type erasure.
Here's an example that look like your example but with static polymorphism:
QUESTION
As far as I know, NEAT (NeuroEvolution of Augmenting Topologies) is an algorithm that uses the concept of evolution to train a neural network. On the other hand, reinforcement learning is a type of machine learning with the concept of "rewarding" more successful nodes.
What is the difference between these two fields as they seem to be quite similar? Or is NEAT derived from reinforcement learning?
...ANSWER
Answered 2017-Feb-19 at 00:27In short they have barely anything in common.
NEAT is an evolutionary method. This is a black box approach to optimization of functions. In this case - performance of the neural net (which can be easily measured) wrt. to its architecture (which you alter during evolution).
Reinforcement learning is about agents, learning policies to behave well in the environment. Thus they solve different, more complex problem. In theory you could learn NEAT using RL, as you might pose the problem of "given a neural network as a state, learn how to modify it over time to get better performance". The crucial difference will be - NEAT output is a network, RL output is a policy, strategy, algorithm. Something that can be used multiple times to work in some environment, take actions and obtain rewards.
QUESTION
I'm working on a neuroevolution project in which there is an array full of active entities and dead entities. When the active entities die, they are removed from the active list and placed into the dead list. I frequently have this error when removing an entity from the active list: ValueError:
...ANSWER
Answered 2018-Aug-16 at 03:56Mutating a list that you are iterating over is a recipe for disaster. Consider the following simple case:
QUESTION
I've recently read the original paper about NeuroEvolution of Augmenting Topologies by Kenneth O. Stanley and am now trying to prototype it myself in JavaScript. I stumbled across a few questions I can't answer.
My questions:What is the definition of "structural innovation", and how do I store these so I can check if an innovation has already happened before?
However, by keeping a list of the innovations that occurred in the current generation, it is possible to ensure that when the same structure arises more than once through independent mutations in the same generation, each identical mutation is assigned the same innovation number
Is there a reason for storing the type of a node (input, hidden, output)?
In the original paper, only connections have an innovation number, but in other sources, nodes do as well. Is this necessary for crossover? (This has already been asked here.)
How could I limit the mutation functions to not add recurrent connections?
I think that's it for now. All help is appreciated.
The relevant parts of my code: Genome ...ANSWER
Answered 2018-Apr-02 at 16:59This is not the average JS question! Thanks for the links, it's a really interesting paper. I can't claim to be an expert, I have only done toy GA problems, but I did read this paper and related ones. Here is what I understand:
I think all you need to worry about is whether a parent, by mutation, produces the same novel gene more than once in a generation. That is, two children, whose gene with the newest innovation number are identical. You can cull those right away. I think they say that it is possible for the same gene to appear in two species at the same time, and they basically say that's fine, that's rare enough not to worry about.
I can find at least one reason: "In NEAT, a bias is a node that can connect to any node other than inputs."
- I believe your question is "must nodes have an innovation number to do crossover?" The answer is no. In the original paper (e.g. Figure 4) they show crossover implemented in a way where only connections have innovation numbers.
- If you want to change the mutation function to be architecture aware, rather than avoiding recurrent structure, you might want to explicitly add structures you do want. Suppose you want to avoid recurrent connections because you are evolving an image classifier, and you know that convolutions are more suited to the task. In this case, you want your mutation function to be able to add/remove layers (and the needed connections). This was explored in detail last year by Google Brain:
Some of the mutations acting on this DNA are reminiscent of NEAT. However, instead of single nodes, one mutation can insert whole layers—i.e. tens to hundreds of nodes at a time. We also allow for these layers to be removed, so that the evolutionary process can simplify an architecture in addition to complexifying it.
Based on your comment about your motivation for question 4, I think you are mistaken. In the XOR example in the original paper, figure 5, they show a starting phenotype that involves no hidden layer. This starting phenotype is not a solution to the XOR problem, but it provides a good starting point: "NEAT is very consistent in finding a solution. It did not fail once in 100 simulations." That is without any penalization for recurrence.
QUESTION
I'm studying machine learning and I found this code in github, but I'm having some problems to make it work correctly, and I also do not have experience with python which is not making things much easier hahaha
...filhos = np.zeros( (n_filhos, n_vars) ) is returning this error:
Traceback (most recent call last): File "D:\GitHub\evoman_framework\optimization_individualevolution_demo.py", line 272, in filhos = cruzamento(pop) # crossover File "D:\GitHub\evoman_framework\optimization_individualevolution_demo.py", line 171, in cruzamento filhos = np.zeros( (n_filhos, n_vars) ) TypeError: only integer scalar arrays can be converted to a scalar index
ANSWER
Answered 2017-Oct-16 at 20:46You get this error because your n_filhos
or n_vars
type is not an integer. I can run only the first variable separately and it returns the array.
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Install neuroevolution
You can use neuroevolution like any standard Python library. You will need to make sure that you have a development environment consisting of a Python distribution including header files, a compiler, pip, and git installed. Make sure that your pip, setuptools, and wheel are up to date. When using pip it is generally recommended to install packages in a virtual environment to avoid changes to the system.
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