# Demos

## Introductory demos

These demos illustrate core DOLFIN/FEniCS usage and are a good way to begin learning FEniCS. We recommend that you go through these examples in the given order.

1. Getting started: Solving the Poisson equation.

2. Solving nonlinear PDEs: Solving a nonlinear Poisson equation

3. Using mixed elements: Solving the Stokes equations

4. Using iterative linear solvers: Solving the Stokes equations more efficiently

## More advanced demos

These examples typically demonstrate how to solve a certain PDE using more advanced techniques. We recommend that you take a look at these demos for tips and tricks on how to use more advanced or lower-level functionality and optimizations.

- Implementing a nonlinear hyperelasticity equation

- Using a mixed formulation to solve the time-dependent, nonlinear Cahn-Hilliard equation

- Computing eigenvalues of the Maxwell eigenvalue problem

## All documented demos

- Poisson equation
- A simple eigenvalue solver
- Built-in meshes
- Mixed formulation for Poisson equation
- Biharmonic equation
- Auto adaptive Poisson equation
- Cahn-Hilliard equation
- Stable and unstable finite elements for the Maxwell eigenvalue problem
- Hyperelasticity
- Nonlinear Poisson equation
- Singular Poisson
- Poisson equation with pure Neumann boundary conditions
- Interpolation from a non-matching mesh
- Stokes equations with an iterative solver
- Time-integration of elastodynamics equation