Skip to main content
Version: Next

7. Agent Aspect

In this seventh step, we will focus on the display and more specifically the aspects of the agents: how they are represented. It can be a simple shape (circle, square, etc.), an icon, a polygon (see later GIS support).

Formulation

  • Definition of two new aspects for the prey and predator agents:
    • A icon
    • A square with information about the agent energy
  • Use of the icon aspect as default aspect for the prey and predator agents.

Model Definition

parent species

We add a new variable of type image_file (a particular kind of file) called my_icon to the generic_species. We define as well two new aspects:

  • icon: draw the image given by the variable my_icon,
  • info: draw a square of side size size and color color and draw as a text the energy of the agent (with a precision of 2 digits).
species generic_species {
...
image_file my_icon;
...
aspect base {
draw circle(size) color: color ;
}
aspect icon {
draw my_icon size: 2 * size ;
}
aspect info {
draw square(size) color: color ;
draw string(energy with_precision 2) size: 3 color: #black ;
}
}

prey species

We specialize the prey species from the generic_species species as follows:

  • definition of the initial value of the agent variables:
species prey parent: generic_species {
...
image_file my_icon <- image_file("../includes/data/sheep.png") ;
...
}

The image file is here: Icon for the prey agents..

You have to copy it in your project folder: includes/data/.

predator species

As done for the prey species, we specialize the predator species from the generic_species species:

  • definition of the initial value of the agent variables:
species predator parent: generic_species {
...
image_file my_icon <- image_file("../includes/data/wolf.png") ;
...
}

The image file is here: Icon for the predator species..

You have to copy it in your project folder: includes/data/.

display

We change the default aspect of the prey and predator agents to icon aspect.

output {
display main_display {
grid vegetation_cell lines: #black ;
species prey aspect: icon ;
species predator aspect: icon ;
}
}

We define a new display called info_display that displays the prey and predator agents with the info aspect.

output {
display info_display {
grid vegetation_cell lines: #black ;
species prey aspect: info;
species predator aspect: info;
}
}

Complete Model

msi.gama.models/models/Tutorials/Predator%20Prey/models/Model%2007.gaml
loading...