# Installation

## Prerequisites

### Getting Python

If you do not have Python installed on your machine, it can be downloaded from [https://www.anaconda.com/distribution/](https://www.anaconda.com/distribution/).

### Xfoil

AirfoilDatabase calculates section properties using a code called Xfoil, written by MIT. The Xfoil executable can be downloaded for Windows at [http://web.mit.edu/drela/Public/web/xfoil/](http://web.mit.edu/drela/Public/web/xfoil/). To get this to work with AirfoilDatabase, you will need to make sure to add the Xfoil executable to your path environment variable. If you're not familiar with editing environment variables, you can find a quick tutorial [here](https://www.computerhope.com/issues/ch000549.htm). Just follow the outlined procedure to add Xfoil to Path.

Xfoil is also available as a package on some Linux distributions and can be installed like any other package. For example on Mint:

    $ sudo apt-get install xfoil

For other Unix (Linux/Mac) systems where a package is not available, compiling from the Fortran source code is required. Step by step instructions on how to do this can be found on the page [Compiling Xfoil on Unix](xfoil_installation).

**AirfoilDatabase must be able to send only the command ```xfoil``` to the system to run the Xfoil executable.** To make sure Xfoil is properly configured, type "xfoil" into your terminal application and verify this runs the application (the interface for Xfoil is entirely terminal-based).

## Getting the Source Code

You can either download the source as a ZIP file and extract the contents, or clone the AirfoilDatabase repository using Git. If your system does not already have a version of Git installed, you will not be able to use this second option unless you first download and install Git. If you are unsure, you can check by typing `git --version` into a command prompt. We recommend the second option as this makes updating the code much easier.

### Downloading source as a ZIP file

1. Open a web browser and navigate to [https://github.com/usuaero/AirfoilDatabase](https://github.com/usuaero/AirfoilDatabase)
2. Make sure the Branch is set to `Master`
3. Click the `Clone or download` button
4. Select `Download ZIP`
5. Extract the downloaded ZIP file to a local directory on your machine

### Cloning the Github repository

1. From the command prompt navigate to the directory where AirfoilDatabase will be installed. Note: git will automatically create a folder within this directory called MachUpX. Keep this in mind if you do not want multiple nested folders called AirfoilDatabase.
2. Execute `git clone https://github.com/usuaero/AirfoilDatabase`

## Installing

Navigate to the root (AirfoilDatabase/) directory and execute

`pip install .`

Please note that any time you update the source code, the above command will need to be run.