README

Code repository for Brochhagen, Franke & van Rooij (2018): Coevolution of lexical meaning and pragmatic use. Cognitive Science. DOI: 10.1111/cogs.12681.

This repository is mantained by Thomas Brochhagen (thomasbrochhagen@gmail.com).

Get in touch if you have any questions!

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Requirements

The code is written in python 2.7

A conda environment, named coevo and supplied within, fulfills all the requirements to run the code

To import and activate it, run:

conda env create --file environment.yaml #import environment from YAML
conda activate coevo 

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Illustration of dynamics in a reduced type space

The script 2d/2d-plots.py illustrates independent and joint effects of the replicator and the mutator dynamic using a reduced type space.

Running coevo/2d/2d-plots.py generates Figure 2 of the paper.

The plot is saved in coevo/plots/2d-dynamics.png.

The posterior parameters and lambda values can be changed as arguments of quiver_contour() (l. 240-242).

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Experiments

The files to run the main experiments on a large type space are found in experiments/

• Run run_experiments.py to automatically compute dynamics for a large number of parameter settings. Otherwise;
• call run_dynamics() from rmd.py to run individual experiments.

Intermediate computations (U and Q matrices) are saved in matrices/ to avoid recomputation.

Both outcomes of individual experimental runs and averages are written to results/

Caution: Estimating the mutation matrix for the full type space can be computationally expensive.

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Files for type generation

A type is a combination of a lexicon an a linguistic behavior to act on it.

• lexica.py has convenience functions to generate all possible lexica for a number of states and messages; to bin them into categories; and to generate a learning prior over them.
• player.py defines the two player behavior classes we consider: literal and Gricean