Finite Size Lyapunov Exponent (FSLE) is a local lagrangian diagnostics that is widely used for the study of transport and mixing processes of oceanographic tracers (Sea surface temperature, Ocean color ...). Its computation is derived from the definition of Finite-Time Lyapunov Exponent that allows the identification of Lagrangian Coherent Structures.

The code used to compute LE, was developed in collaboration between LOCEAN (F. d'Ovidio) and CLS, is available under GNU General Public License

Given a time series of meso-scale velocity field, this code computes corresponding sub-mesoscale maps of backward or forward FLSE or FTLE. It also compute other diagnostics such as orientation of Finite-Time Lyapunov Vectors.

Install with Ubuntu package

Now you can install the library from a Debian Package, if you are using Ubuntu 12.04 or 16.04. Under Ubuntu 12.04, the package provides a library for Python2 and for Ubuntu 16.04 a library for Python3. To install,

  1. download the wanted archive:

  2. unzip it:

  3. then install (you need root privilege to launch this command):

    sudo apt-get install ubuntu_16_04/python3-lagrangian_2.1.0_amd64.deb

If you got some dependency problems, the you need to execute this last command to fix it:

sudo apt install -f

First steps with the software

To know on how to build the library from sources and how to use the software


For a complete description on Lagrangian analysis