This code tries to simulate a pedestrian flow in two crossing streets.

The rules of the pedestrian behaviour are encoded into the following equations of motion:

$$ \frac{d\boldsymbol{r}}{dt} = \boldsymbol{v}_i(t) $$

$$ \frac{d \boldsymbol{v}i}{dt} = f{tot} (t) / m $$

with $m$ being the mass and $f_{tot}$, the total force. The total force it self is calculated by

$$ f_{tot} = f_{inter} + f_{drive} $$

Where $f_{inter}$ is the force from interactions with other pedestrians and walls ans the friving force is the force toward the destination of pedestrians.

This code base is using the Julia Language and DrWatson to make a reproducible scientific project named

PedestFlow

It is authored by Ehsan Irani.

To (locally) reproduce this project, do the following:

0. Download this code base. Notice that raw data are typically not included in the git-history and may need to be downloaded independently.
1. Open a Julia console and do:

   julia> using Pkg
   julia> Pkg.add("DrWatson") # install globally, for using `quickactivate`
   julia> Pkg.activate("path/to/this/project")
   julia> Pkg.instantiate()
   

This will install all necessary packages for you to be able to run the scripts and everything should work out of the box, including correctly finding local paths.

First include the main code by

julia> include(srcdir("ehsan.jl"))

Then define the pedestrian-flow model by

julia> model = initialize_model(n_persons = 1, ϕ=1.0, dt=0.005, σ=0.5, γ=0.0, m=1, θ = 3π/4, Rv=4, β=0.0, seed=11)

here ϕ is the rate of adding new people, $\theta$ is the view angle and Rv is the visual board of pedestrians.

After defining the model, one can run the simulation by

julia> adf, _ = run!(model, agent_step!, model_step!, Int(120 ÷ model.dt);
         agents_first = false,
         adata = [:pos, :vel])

with adf is a dataframe containing the position and velocity informations of agents. One can save it by

julia> using CSV
julia> CSV.write(datadir(savename("agents", "csv")), adf)

Using the following command one can record an animation of the simulation to animation.mp4:

julia> abmvideo(
        plotsdir("animation.mp4"), model, agent_step!, model_step!;
        ac=ac,
        framerate = 120, spf=6, frames = 2000,
        title = "Pedestrian flow", static_preplot!
    )

Here the population size of the simulations at different flow rates is plotted.