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Neural Networks From Scratch

An in-depth exploration of Deep Neural Networks (DNNs) implemented from scratch without high-level frameworks

August 2023 View Code
Deep Learning Neural Networks Python NumPy Machine Learning Education

Overview

An in-depth exploration of Deep Neural Networks (DNNs) implemented entirely from scratch. This project demonstrates a fundamental understanding of how neural networks work at the mathematical level, without relying on high-level deep learning frameworks.

Project Description

This educational project builds a complete neural network implementation using only NumPy, covering:

  • Forward Propagation: Computing activations layer by layer
  • Backpropagation: Calculating gradients for weight updates
  • Activation Functions: Implementation of various activation functions (sigmoid, ReLU, tanh)
  • Loss Functions: Cross-entropy, MSE, and other loss calculations
  • Optimization: Gradient descent and advanced optimizers
  • Training Loop: Complete training pipeline from scratch

Learning Outcomes

Building neural networks from scratch provides invaluable insights into:

  1. The mathematical foundations of deep learning
  2. How gradient descent and backpropagation actually work
  3. The role of different hyperparameters
  4. Common pitfalls and debugging strategies
  5. Why modern frameworks are structured the way they are

Implementation Details

The implementation covers all essential components:

  • Matrix operations for efficient computation
  • Layer abstractions for modular network design
  • Training utilities for model optimization
  • Visualization tools for understanding network behavior

Technical Report

For a detailed description, mathematical derivations, and comprehensive analysis, view the technical report and source code on the GitHub repository.

The report includes:

  • Mathematical foundations and derivations
  • Implementation details and code architecture
  • Experimental results and analysis
  • Comparisons with standard frameworks
  • Lessons learned and best practices

Why Build From Scratch?

While modern frameworks like PyTorch and TensorFlow are essential for practical applications, implementing neural networks from scratch:

  • Deepens understanding of fundamental concepts
  • Provides insights into optimization and numerical stability
  • Helps debug complex models in production
  • Builds intuition for network architecture design
  • Demonstrates mastery of machine learning fundamentals