Ivankarez.NeuralNetworks 4.2.0

NeuralNetworks

Introducing a lightweight and specialized neural network library for C#, meticulously designed to complement evolutionary algorithms. Our library is optimized for the crucial task of computing forward passes within neural networks, without the overhead of built-in backpropagation or conventional learning algorithms.

Key Features:

• Efficiency and Memory Optimization: Our neural network library prioritizes resource efficiency, minimizing memory usage and allocations. It achieves this by utilizing C# float arrays for inputs and outputs, while intelligently reusing arrays to enhance performance across successive passes.
• Keras like API for a familiar interface.
• No extra dependencies. Makes it easy to drop it into your Unity or C# project as a single DLL file.

Getting Started

Install

You can install NeuralNetworks from NuGet. For Unity projects, it's is recommended to install it using NuGetForUnity.

dotnet add package Ivankarez.NeuralNetworks

If you prefer, you can also drop it into your project as a DLL file. You can download the latest build from the current release.

Basic Usage

Creating a simple neural network with dense layers should be very similar if you are familiar with keras. You can reach all the functionality through the NN class from the Ivankarez.NeuralNetworks.Api namespace. This is the base class to declare your network. The NN api provides an easy way to access the capabilities of the library. You can use NN.Layers to create new layers, NN.Activations to access activation functions and so on. More of this in the Features section.

Sample code to create layered model with 3 dense layers. The node count of the last layer will determine the output size of the network. In this example we create a network with this configuration:

• An input of size 3
• A dense layer with 10 neurons
• A dense layer with 3 neurons, using the Tanh activation
• A dense layer with 2 neurons. Since this is the last layer, it means this network will have an output size of 2.

using Ivankarez.NeuralNetworks.Api;

var neuralNetwork = NN.Models.Layered(NN.Size.Of(3),
        NN.Layers.Dense(10),
        NN.Layers.Dense(3, activation: NN.Activations.Tanh()),
        NN.Layers.Dense(2));

var result = neuralNetwork.FeedForward(new float[] {1, 2, 3});
Console.WriteLine($"Result: {string.Join(", ", result)}");

Acessing paramters

To access parameters of a network (weights, biases etc...) you can iterate trough the layers of a model, and access it's parameters via the Parameters property.

var model = NN.Models.Layered(/*Any model config*/);
foreach(var layer in model.Layers) {
        var parameters = layer.Parameters;
}

If you want just a simple float[] of the parameters to store them (or used them as a DNA in a genetic algorithm), you can use the GetParametersFlat and SetParametersFlat extension methods of the model.

var model = NN.Models.Layered(/*Any model config*/);
var oldParameters = model.GetParametersFlat();
var newParameters = /* New parameters as a float array */;
model.SetParametersFlat(newParameters);

If you just want to count the number of parameters, you can use the CountParameters() extension method of the model.

Demo Programs

There is a NeuralNetworks.Demos repository, where we plan to collect different demos for this library. Currently it only contains a simple C# application where we train a neural network to learn classifying images of 'A' and 'B' characters.

Features

This is a simple list of available features of this package. If you look for available parameters or default values, you can take a look at the corresponding API codes linked in the section headers.

Models

• Layered Model

Layers

• Dense Layer
• Simple Recurrent Layer
• 1 dim convolution layer
• 2 dim convolution layer
• 1 dim pooling layer (min, max, average, sum)
• 2 dim pooling layer (min, max, average, sum)

Activations

• Linear
• Clamped linear
• Tanh
• Sigmoid
• Relu
• Leaky Relu

Initializers

• Zeros
• Constant
• Uniform
• Normal
• Glorot uniform
• Glorot normal

Size

• Of(int): Create a Size1D object
• Of(int, int): Create a Size2D object

Contributions

All contributions are welcome. For a starting point it's quite easy to implement other activation functions and initializers. Also extending test coverage, or simplify tests can be a good starting point.