## Observation

### Class #10 (Tue., Feb 13)

## Homework

Homework #7 is due today: Railsback & Grimm, Ch. 6, Ex. 6.2, 6.3, 6.5 (everyone) and Ex. 6.4, 6.7 (grad. students). See the homework assignment sheet for details.

## Reading:

- Railsback & Grimm, Ch. 9.

### Reading Notes:

In this chapter, we examine how to detect and record the properties of a model that we want to study.

The article, D. Kornhauser, U. Wilensky, and W. Rand. (2009). “Design guidelines
for agent-based model visualization,” *Journal of Artificial Societies and Social
Simulation* **12**, 1
is available online at http://jasss.soc.surrey.ac.uk/12/2/1.html.

I have posted a refresher guide for NetLogo programming on the class web site at https://ees4760.jgilligan.org/files/models/chapter_09/ch9_ex8_Netlogo_exercises.pdf

**Errata for Chapter 9:**

Section 9.3, p. 119: The discussion of histograms mentions potential difficulties setting the

*x*axis to a useful range, so all the bars are visible. One solution is to use the`set-plot-x-range`

primitive. For example, add this statement:`set-plot-x-range (min [elevation] of turtles) (max [elevation] of turtles)`

just before the statement:

`histogram [elevation] of turtles`

Or, if the histogram should always start at zero:

`set-plot-x-range 0 max [elevation] of turtles`

(You may need to use primitives such as

`ceiling`

and`precision`

to convert the inputs to`set-plot-x-range`

to nice round numbers.)