# Installation

This page will guide you through **downloading and installing** QETLAB. This process should be quick and easy (taking roughly 5 minutes). First try following the instructions in the following box. If you do not have any trouble following these instructions and getting everything working, then great! If you need more detailed instructions, continue reading below.

Download and Install QETLABStep 1: Download QETLAB (current version: 0.9, last updated: January 12, 2016)Step 2: Unzip the file in your MATLAB scripts directoryStep 3: Download and install CVX 2.1 |

## More detailed instructions

Here we will expand on the three steps that we outlined above, in case you have any trouble completing any of them.

### Step 1: Download QETLAB

This step is easy enough. Simply download one of the following two files, depending on which operating system you are using.

Windows/Mac | Linux |
---|---|

QETLAB v0.9 (.zip archive) | QETLAB v0.9 (.tar.gz archive) |

### Step 2: Unzip the file in your MATLAB scripts directory

First, extract the .zip or .tar.gz archive (every modern operating system has built-in tools for extracting archives like this) – this will create a directory called "`QETLAB-0.9`".

- If you know where your MATLAB scripts directory is and you are comfortable adding scripts to MATLAB's path, then do so with QETLAB (and its subfolders).

- Otherwise, move the "
`QETLAB-0.9`" directory to wherever you want it on your computer (for the sake of these instructions, let's suppose that the directory is now located at`C:\Users\Nathaniel\MyFiles\QETLAB-0.9`). Then, within MATLAB, type the following (replacing the path`C:\Users...`with whatever the path is on your own computer):

`addpath(genpath('C:\Users\Nathaniel\MyFiles\QETLAB-0.9'))`

You should now be able to use some of basic functions of QETLAB. For example, you could try running the following two lines of code, which generate a random density matrix and then check whether or not it has positive partial transpose:

```
>> rho = RandomDensityMatrix(9);
>> IsPPT(rho)
ans =
0
```

### Step 3: Download and install CVX

While this step is not necessary if you only care about some of QETLAB's most basic functions, it is needed to unlock many of the advanced features of QETLAB. CVX is a free convex optimization toolbox for MATLAB that is *heavily* integrated with QETLAB. Many of QETLAB's advanced functions rely on CVX (if a QETLAB function requires CVX, it will say so at the top-right corner of its documentation page), and in general CVX is just handy to have around.

IMPORTANT NOTE! Currently CVX 2.1 is the stable version and is compatible with QETLAB. USE CVX 3.0b AT YOUR OWN RISK!

To download and install CVX, follow the **instructions on the CVX website**.