Code

Introduction

The AHA Model is implemented in modern Fortran (F2003-F2008). Fortran was chosen due to its simplicity (meaning relatively shallow learning curve), combined with high computational performance, advanced array manipulation operators and built-in parallel computing features.

Reference Implementation

R1: Vertical migration in mesopelagic fish

The reference model R1 follows the simple mesopelagic fish system developed by Giske et al., (2013, 2014). Here a population of fish lives in a water column together with stochastic zooplankton food and predators. Zooplankton is randomly distributed within a thin vertical layer. Illumination changes according to the diurnal cycle and the zooplankton executes diurnal migrations in a pattern opposite to the light cycle. Thus, this simple system provides physical gradients, environmental dynamics and significant stochasticity. Decision making and action selection in the fish agents in R1 is based on elementary self-awareness: the ability of the agent to assess its own emotional state and use this information for decision making.

DOI

A reference implementation of the model is here: AHA Model Documentation. It is also available as a PDF file

HED18: Decision-making in vertical migration system

The computer code for the original study: Giske, J., Eliassen, S., Fiksen, O., Jakobsen, P.J., Aksnes, D.L., Mangel, M. and Jorgensen, C. (2014) The emotion system promotes diversity and evolvability. Proceedings of the Royal Society B: Biological Sciences 281, 20141096. doi:10.1098/rspb.2014.1096

The Fortran code is available on Dryad: doi:10.5061/dryad.m6k1r

Git mirror: https://git.app.uib.no/Sergey.Budaev/h18_2015

Code Repository

The full source codes for all the models are maintained in an internal Subversion repository at the University of Bergen.

AHA Modelling Tools Manual

The AHA Model uses various tools from the HEDTOOLS suite. HEDTOOLS documentation is available in the AHA Modelling Tools Manual. It can also be downloaded as a PDF document.