QuTiP 4.4 released 4 July 2019 (version 4.4.1 released 13 August 2019)

[Nathan Shammah]

Dear QuTiP users, 

We are very pleased to announce the release of QuTiP v 4.4. 

Many thanks to Eric Giguère for contributing the major features of this release. Thanks to everyone else who contributed with enhancements and bug fixes.
Big thanks to Eric Giguère for managing also the initial release (4.4.0) and some bug fixes (4.4.1). 

As usual there are conda-forge, pip and source download installs available.

The notebooks can be run interactively using My Binder at github.com/qutip/qutip-notebooks .

Check out the news section on the website for timely updates http://qutip.org/news .

For details of the release, see below.

All the best to the user base, we hope that this new version will help in your research and study.

Nathan Shammah

on behalf of the QuTiP admin team

Change Log Version 4.4.0 (July 03, 2019) 

MAJOR FEATURE: Added methods and techniques to the stochastic solvers, "smesolve" (by Eric Giguère) which allow to use a much broader set of solvers and much more efficiently. 

MAJOR FEATURE: Optimization of the montecarlo solver, "mcsolve" (by Eric Giguère). Computation are faster in many cases. Collapse information available to time dependant information. 

Added the "QobjEvo" class and methods (by Eric Giguère), which is used behind the scenes by the dynamical solvers, making the code more efficient and tidier. More built-in function available to string coefficients. The coefficients can be made from interpolated array with variable timesteps and can obtain state information more easily. 

Time-dependant collapse operator can have multiple terms. New "wigner_transform" and "plot_wigner_sphere" function (by Nithin Ramu). 

- "ptrace" is faster and work on bigger systems, from 15 Qbits to 30 Qbits. 

- QIP module: added the possibility for user-defined gates, added the possibility to remove or add gates in any point of an already built circuit, added the "molmer_sorensen" gate, and fixed some bugs (by Boxi Li). 

- Added the quantum Hellinger distance to qutip.metrics (by Wojciech Rzadkowski). 

- Implemented possibility of choosing a random seed (by Marek, marekyggdrasil). 

- Added a code of conduct to Github. 

Bug Fixes 

- Fixed bug that made QuTiP incompatible with SciPy 1.3. 

- quite.cite() is improved. 

- Added matplotlib as optional dependency and updated numpy and scipy requirements. 

- Fixed matrix generating coherent spin states in qutip.piqs to include complex coefficients.

Notebooks (http://qutip.org/tutorials.html)

- New notebook on Monte-Carlo vs stochastic trajectories: Cat states become coherent states (by Fabrizio Minganti)

- New notebook on Von Neumann entropy in permutational symmetric systems with local dissipaiton (by Nathan Shammah)

- New notebook with a quantum mechanics lecture on the theory of measurement using the Stern-Gerlach experiment as example (by Simon Cross)

[C.R. Wie]

Hello,

I need to plot three Bloch spheres at the same time with a different state vector in each of them.  

Is it possible with Qutip?

Thanks.