Strengths is a modeling and simulation tool for reaction diffusion systems, interfaced as a python package. It stands for "Simulation and modeling Tool for Reaction diffusion Networks in Graphs and Tri-dimentionnal Heterogenous Systems". The design of reaction-diffusion systems if facilitated by the use of dictionary as a way to define most of the key Objects.

The package can be installed from the Python Package Index, with

pip install strengths

Alternatively, you can build strengths from source. More details on how to do so are given in the documentation, in the "Building strengths from source" section.

Once it is successfully installed, you should be able to import it in python. Below is a short example, featuring the simulation of the trajectory for a simple reaction system :

# importing strengths

import strengths as strn
import strengths.plot as strnplt

# defining a reaction system :
# this one have two species, A
# and B. One can be converted to the other,
# through the reversible reaction A <=> B.

system = strn.rdsystem_from_dict({
    "network" : {
        "species" : [
            {"label" : "A", "density" : 150},
            {"label" : "B", "density" : 50}
            ],
        "reactions" : [
            {"eq" : "A -> B", "k+" : 0.01, "k-" : 0.012}
            ]
        }
    })

# running a simulation
trajectory = strn.simulate(system, t_sample=list(range(500)))

# plotting the trajectories of A and B
strnplt.plot_trajectory(trajectory, ["A", "B"])

More examples, using more advanced features - especially diffusion -, are available in the documentation, in the "Using strengths" section.

Detailed information on the package and how to use it are given in the documentation. Especially, to get started with the package, you may look at the "Using Strengths" section, which presents the key functionalities through examples. For detailed and more exhaustive information on the accessible interface, please refer to the "API Reference" section, where all relevant functions, classes, methods and attributes are covered in detail.

Strengths have a repository hosted on GitHub.

If you wish to contribute to the package, whether by giving your feedback, reporting bugs or errors, improving the documentation or writing code, please refer to the project's community and contribution guidelines.

Running "run_all_tests.py" in the "tests" directory will execute at once all unit tests for the package.

Strengths's source code and documentation are licensed under the terms of the MIT Licence. You'll find the licence text in your strengths installation root file, or in the root file of the project's GitHub repository.

• Thibault Fillion
• Francesco Piazza