Controlling rogue waves and soliton gases

Topological control of extreme waves

From optics to hydrodynamics, shock and rogue waves are widespread. Although they appear as distinct phenomena, transitions between extreme waves are allowed. However, these have never been experimentally observed because control strategies are still missing. We introduce the new concept of topological control based on the one-to-one correspondence between the number of wave packet oscillating phases and the genus of toroidal surfaces associated with the nonlinear Schrödinger equation solutions through Riemann theta functions. We demonstrate the concept experimentally by reporting observations of supervised transitions between waves with different genera. Considering the box problem in a focusing photorefractive medium, we tailor the time-dependent nonlinearity and dispersion to explore each region in the state diagram of the nonlinear wave propagation. Our result is the first realization of topological control of nonlinear waves. This new technique casts light on shock and rogue waves generation and can be extended to other nonlinear phenomena.

Nature Communications volume 10, Article number: 5090 (2019)

Docker, mpi, fftw, fftw-mpi

Docker enables to create containers for your program with all the libraries installed.

This avoids to reinstall all the libraries (say mpich, fftw…) to any user and in new systems

The user just needs to pull the container from a repository. For example nonlinearxwaves/base

I write C++ scientific computing programs with mpich, fftw-mpi and random numbers libraries (as sprng5), wich I need to run in both windows and linux systems. Docker simplifies a lot the deployment but also the development of the code.

nonlinearxwaves/base is a container with all of that

After installing Docker you run

docker login

Then you pull the docker image

docker pull nonlinearxwaves/base:0.1

You list the available images with

docker images -a

You identify the image id (in this example it is ec56f7250d5a)

REPOSITORY             TAG                 IMAGE ID            CREATED             SIZE
nonlinearxwaves/base 0.1 ec56f7250d5a 42 hours ago 1.13GB

You run the image with (you must replace the image id with your image id)

docker run -i -t ec56f7250d5a 

And you are in a shell with all the libraries installed and you may compile and run your mpi application in the usual way. In this image you will be the user “user”

user@2ff281ad4621:~$

The number 2ff281ad4621 is the container id that is now running (similar to a virtual machine)

This works with Windows and Linux (and also Mac, but I did not test)

You may also create your images with the Dockerfile

Is docker fast ? or is it better not to use a container? we will test …