A Practical Introduction to pymdp: A Two-Part Guide to Active Inference in Python

Here are descriptions for a two-part video series from the Active Inference Institute.  These videos introduce pymdp, a powerful Python package for researchers and developers working with active inference and the Free Energy Principle. 🧠 The first video provides a high-level overview of the package, while the second dives into a practical coding demonstration. Together, they offer a comprehensive guide from theory to application.

Active Inference ModelStream 007.1 ~ Conor Heins & Daphne Demekas ~ pymdp

This video provides an overview of pymdp, a Python package designed for active inference. Active inference is a framework for modeling decision-making and planning based on the Free Energy Principle, which posits that intelligent agents act to minimize surprise or uncertainty about their world. The pymdp package allows researchers to simulate how agents achieve this through both perception and action. It was created as a more accessible, user-friendly alternative to traditional MATLAB tools. The package is modular, integrates with other Python libraries like PyTorch, and has future plans to incorporate JAX for deep learning applications, making it a powerful tool for neuroscience and AI researchers studying the Free Energy Principle.

Active Inference ModelStream 007.2 ~ pymdp

This video, the second part of a series, demonstrates how to implement an active inference agent using the pymdp library. The presentation focuses on building a generative model for a contextual multi-armed bandit task. Key concepts explained include the four main components of a POMDP—the A, B, C, and D matrices—which represent the agent's beliefs. The video also introduces the concept of factorized state spaces to manage computational complexity and details how an agent can learn by updating its model parameters based on experience. The ultimate goal is to show how these agents, following the Free Energy Principle, can engage in both optimal and information-seeking behavior.