6. Charts

This 6th step illustrates how to display charts.

Formulation

• Add a chart to display the evolution of the road destruction: the mean value of the destruction_coeff of the road agents, and its max value (refreshed every 10 simulation steps).
• Add a chart to display the activity of the people agent (working or staying home, refreshed every 10 simulation steps).

Model Definition

chart display

First, we add a chart of type series to display the road destruction evolution. To compute the mean of the destruction_coeff, we combine the mean and collect operators. collect takes a container and an expression as operands and will compute a new list, each element being the evaluation on the container operand of the expression. mean computes the average of all the elements of a list. For the max, we use the max_of operator. (Note that the operator mean_of also exists to replace mean and collect).

     output {
         display chart_display refresh:every(10#cycles) {
             chart "Road Status" type: series size: {1, 0.5} position: {0, 0} {
                 data "Mean road destruction" value: mean (road collect each.destruction_coeff) style: line color: #green ;
	         data "Max road destruction" value: road max_of each.destruction_coeff style: line color: #red ;
	     }
             ...
         }
     }

Second, we add a chart of type pie to display the activity of the people agents. We use for that the objective variable of the people agents and the count operator that allows computing the number of elements of a list that verify a condition.

    output {
      ...
      display chart_display refresh: every(10#cycles) {
          ...
          chart "People Objectif" type: pie style: exploded size: {1, 0.5} position: {0, 0.5}{
	       data "Working" value: people count (each.objective="working") color: #magenta ;
	       data "Resting" value: people count (each.objective="resting") color: #blue ;
	  }
     }
   }

We chose to display the 2 charts on the same display. As a consequence, we specified the size and position of each of them to define the layout of this display.

Complete Model

https://github.com/gama-platform/gama.old/blob/GAMA_1.9.3/msi.gama.models/models/Tutorials/Road%20Traffic/models/Model%2006.gaml