Introduction

Welcome to the PyDy project website. PyDy, short for Python Dynamics, is a both a workflow that utlizes an array of scientific tools written in the Python programming language to study multibody dynamics and a set of software packages that help automate and enhance the workflow. The core of this toolset is the SymPy mechanics package which generates symbolic equations of motion for complex multibody systems and PyDy which extends the SymPy output to the numerical domain for simulation, analyses, and visualization. PyDy builds on the popular scientific Python stack such as NumPy, SciPy, IPython, matplotlib, Cython, and Theano.

Site Overview

PyDy Package’s documentation!

This is the central page for all PyDy’s Documentation.

PyDy

PyDy, short for Python Dynamics, is a tool kit written in the Python programming language that utilizes an array of scientific programs to enable the study of multibody dynamics. The goal is to have a modular framework and eventually a physics abstraction layer which utilizes a variety of backends that can provide the user with their desired workflow, including:

• Model specification
• Equation of motion generation
• Simulation
• Visualization
• Publication

We started by building the SymPy mechanics package which provides an API for building models and generating the symbolic equations of motion for complex multibody systems. More recently we developed two packages, pydy.codegen and pydy.viz, for simulation and visualization of the models, respectively. This Python package contains these two packages and other tools for working with mathematical models generated from SymPy mechanics. The remaining tools currently used in the PyDy workflow are popular scientific Python packages such as NumPy,SciPy, IPython, and matplotlib (i.e. the SciPy stack) which provide additional code for numerical analyses, simulation, and visualization.

General

If you are familiar with scientific computing and symbolic manipulation with Python you should start with the SymPy vector/mechanics documentation and the PyDy documentation:

• Commands
• Symbolic Vectors [SymPy Docs]
• Symbolic Dynamics [SymPy Docs]
• PyDy Documentation

If you aren’t familiar with scientific computing with Python there are many sources to learn. You can start with the Python programming language itself, with the canonical source being thePython Documentation. The SciPy Lectures are a great intro to scientific computing with Python. Finally, to learn about how to do symbolic manipulation with SymPy, check out the SymPy Documentation, especially the tutorial.

Tutorials

We have a couple of tutorials. The human standing tutorial takes you through an entire workflow for a dynamics and control problem and is a good place to start.

• Beginner’s Tutorial
• Human Balance Tutorial