Installation¶

General Requirements¶

QuTiP depends on several open-source libraries for scientific computing in the Python programming language. The following packages are currently required:

Package	Version	Details
Python	2.7+	Version 3.5+ is highly recommended.
NumPy	1.8+	Not tested on lower versions.
SciPy	0.15+	Lower versions have missing features.
Matplotlib	1.2.1+	Some plotting does not work on lower versions.
Cython	0.21+	Needed for compiling some time-dependent Hamiltonians.
C++ Compiler	GCC 4.7+, MS VS 2015	Needed for compiling Cython files.
Python Headers	2.7+	Linux only. Needed for compiling Cython files.

In addition, there are several optional packages that provide additional functionality:

Package	Version	Details
LaTeX	TexLive 2009+	Needed if using LaTeX in matplotlib figures.
pytest	5.3+	For running the test suite.

We would not recommend installation into the system Python on Linux platforms, as it is likely that the required libraries will be difficult to update to sufficiently recent versions. The system Python on Linux is used for system things, changing its configuration could lead to highly undesirable results. We are recommending and supporting Anaconda / Miniconda Python environments for QuTiP on all platformsx [It is also possible to install the Intel Python Distribution via the conda installer in Anaconda].

Platform-independent Installation¶

QuTiP is designed to work best when using the Anaconda or Intel Python distributions that support the conda package management system.

If you aleady have your conda environment set up, and have the conda-forge channel available, then you can install QuTiP using:

conda install qutip

Otherwise refer to building-conda-environment

If you are using MS Windows, then you will probably want to refer to installation-on-MS-Windows

Building your Conda environment¶

Important

There are no working conda-forge packages for Python 2.7 on Windows. On Windows you should create a Python 3.5+ environment.

The default Anaconda environment has all the Python packages needed for running QuTiP. You may however wish to install QuTiP in a Conda environment (env) other than the default Anaconda environment. You may wish to install Miniconda instead if you need to be economical with disk space. However, if you are not familiar with conda environments and only plan to use if for QuTiP, then you should probably work with a default Anaconda / Miniconda environment.

To create a Conda env for QuTiP called qutip-env:

conda create -n qutip-env python=3

Note the python=3 can be ommited if you want the default Python version for the Anaconda / Miniconda install.

If you have created a specific conda environment, or you have installed Miniconda, then you will need to install the required packages for QuTiP.

recommended:

conda install numpy scipy cython matplotlib pytest pytest-cov jupyter notebook spyder

minimum (recommended):

conda install numpy scipy cython pytest pytest-cov matplotlib

absolute mimimum:

conda install numpy scipy cython

The jupyter and notebook packages are for working with Jupyter notebooks (fka IPython notebooks). Spyder is an IDE for scientific development with Python.

Adding the conda-forge channel¶

If you have conda 4.1.0 or later then, add the conda-forge channel with lowest priority using:

conda config --append channels conda-forge

Otherwise you should consider reinstalling Anaconda / Miniconda. In theory:

conda update conda

will update your conda to the latest version, but this can lead to breaking your default Ananconda enviroment.

Alternatively, this will add conda-forge as the highest priority channel.

conda config --add channels conda-forge

It is almost certainly better to have defaults as the highest priority channel. You can edit your .condarc (user home folder) file manually, so that conda-forge is below defaults in the channels list.

Installing via pip¶

For other types of installation, it is often easiest to use the Python package manager pip.

pip install qutip

More detailed platform-dependent installation alternatives are given below.

Installing from Source¶

Official releases of QuTiP are available from the download section on the project’s web pages

http://www.qutip.org/download.html

and the latest source code is available in our Github repository

http://github.com/qutip

In general we recommend users to use the latest stable release of QuTiP, but if you are interested in helping us out with development or wish to submit bug fixes, then use the latest development version from the Github repository.

Installing QuTiP from source requires that all the dependencies are satisfied. To install QuTiP from the source code run:

python setup.py install

To install OPENMP support, if available, run:

python setup.py install --with-openmp

If you are wishing to contribute to the QuTiP project, then you will want to create your own fork of qutip, clone this to a local folder, and ‘install’ it into your Python env using:

python setup.py develop --with-openmp

import qutip in this Python env will then load the code from your local fork, enabling you to test changes interactively.

The sudo pre-command is typically not needed when installing into Anaconda type environments, as Anaconda is usually installed in the users home directory. sudo will be needed (on Linux and OSX) for installing into Python environments where the user does not have write access.

Installation on MS Windows¶

Important

Installation on Windows has changed substantially as of QuTiP 4.1. The only supported installation configuration is using the Conda environment with Python 3.5+ and Visual Studio 2015.

We are recommending and supporting installation of QuTiP into a Conda environment. Other scientific Python implementations such as Python-xy may also work, but are not supported.

As of QuTiP 4.1, recommended installation on Windows requires Python 3.5+, as well as Visual Studio 2015. With this configuration, one can install QuTiP using any of the above mentioned receipes. Visual Studio 2015 is not required for the install of the conda-forge package, but it is required at runtime for the string format time-dependence solvers. When installing Visual Studio 2015 be sure to select options for the C++ compiler.

The ‘Community’ edition of Visual Studio 2015 is free to download use, however it does require approx 10GB of disk space, much of which does have to be on the system drive. If this is not feasible, then it is possible to run QuTiP under Python 2.7.

Windows and Python 2.7¶

Important

Running QuTiP under Python 2.7 on Windows is not recommended or supported. However, it is currently possible. There are no working conda-forge packages for Python 2.7 on Windows. You will have to install via pip or from source in Python 2.7 on Windows. The ‘MS Visual C for Python 2.7’ compiler will not work with QuTiP. You will have to use the g++ compiler in mingw32.

If you need to create a Python 2.7 conda environment see building-conda-environment, including adding-conda-forge

Then run:

conda install mingwpy

To specify the use of the mingw compiler you will need to create the following file:

<path to my Python env>/Lib/distutils/distutils.cfg

with the following contents:

[build]
compiler=mingw32
[build_ext]
compiler=mingw32

<path to my Python env> will be something like C:\Ananconda2\ or C:\Ananconda2\envs\qutip-env\ depending on where you installed Anaconda or Miniconda, and whether you created a specific environment.

You can then install QuTiP using either the install-via_pip or install-get-it method.

Verifying the Installation¶

QuTiP includes a collection of built-in test scripts to verify that an installation was successful. To run the suite of tests scripts you must have the pytest testing library. After installing QuTiP, leave the installation directory, run Python (or iPython), and call:

import qutip.testing as qt
qt.run()

If successful, these tests indicate that all of the QuTiP functions are working properly. If any errors occur, please check that you have installed all of the required modules. See the next section on how to check the installed versions of the QuTiP dependencies. If these tests still fail, then head on over to the QuTiP Discussion Board and post a message detailing your particular issue.

Checking Version Information using the About Function¶

QuTiP includes an “about” function for viewing information about QuTiP and the important dependencies installed on your system. To view this information:

In [1]: from qutip import *

In [2]: about()