# FEAT2 - Introduction, FAQ, Tutorial

Contents
1 Introduction
2 Short introduction into Fortran 95 for C/C++ programmers
3 Naming conventions in FEAT2
4 Tutorial-based overview - Featflow2/tutorials/tutorial01
5 Basic structures explained
6 FEAT2 programming techniques
7 The L2 projection
8 The Poisson equation
9 The convection-diffusion equation
10 Linear elasticity
11 The Stokes equations
12 The Navier-Stokes equations

### Introduction

• General overview
• Directory structure
• Supported computer systems
• Example:
• Compiling/Executing the Poisson example in Linux
• Opening postprocessing files with Paraview

### Language-specific discussions

• Some basic introduction to Fortran
• Links to the Fortran specification & language books
• Differences between Fortran and C/C++

### Naming conventions in FEAT2

• Filename restrictions
• Source code indention
• Identifier rules for variables, constants and types
• Identifier rules for subroutines and functions
• Exceptions

### Tutorial-based overview - Featflow2/tutorials/tutorial01

• The mesh
• The boundary
• Discretisation structures
• Matrices and vectors
• Linear solver
• Postprocessing

### The L2 projection

• Mathematical background
• Mapping of mathematical objects into data structures
• Solution via a linear solver
• Postprocessing: Error analysis and VTK output
• The Q1~ element - DOFs are not necessarily point values

### The poisson equation

Part 1: The basic equation

• Mathematical background
• Mapping of mathematical objects into data structures
• Solution via a linear solver
• Postprocessing: Error analysis and VTK output

Part 2: Realisation of different boundary conditions

Part 3: Sorting of matrices/vectors

### The convection-diffusion equation

Part 1: The basic equation

• Mathematical background
• Mapping of mathematical objects into data structures
• Solution via a linear solver
• Postprocessing: Error analysis and VTK output

Part 2: Stabilisation techniques

### Linear elasticity

• Mathematical background
• Discussion of boundary conditions
• Mapping of mathematical objects into data structures
• Solution via a linear solver
• Postprocessing: Error analysis and VTK output

### The Stokes equations

Part 1: The basic equation

• Mathematical background
• Discussion of boundary conditions
• Mapping of mathematical objects into data structures
• Solution via a linear solver
• Postprocessing: Error analysis and VTK output

Part 2: Discussion of boundary conditions

Part 3: Nonlinear viscosity

### The Navier-Stokes equations

Part 1: The basic equation

• Mathematical background
• Discussion of boundary conditions
• Mapping of mathematical objects into data structures
• Solution via a linear solver
• Postprocessing: Error analysis and VTK output

Part 2: Discussion of boundary conditions

Part 3: Stabilisation techniques