NetLogo Table Extension

Using

The table extension is pre-installed in NetLogo.

To use the table extension in your model, add a line to the top of your Code tab:

extensions [table]

If your model already uses other extensions, then it already has an extensions line in it, so just add table to the list.

For more information on using NetLogo extensions, see the Extensions Guide

When to Use

In general, anything you can do with an table in NetLogo, you could also just use a list for. But you may want to consider using an table instead for speed reasons. Lists and tables have different performance characteristics, so you may be able to make your model run faster by selecting the appropriate data structure.

Tables are useful when you need to do associate values with other values. For example, you might make a table of words and their definitions. Then you can look up the definition of any word. Here, the words are the "keys". You can easily retrieve the value for any key in the table, but not vice versa.

Unlike NetLogo’s lists and strings, tables are “mutable”. That means that you can actually modify them directly, rather than constructing an altered copy as with lists. If the table is used in more than one place in your code, any changes you make will show up everywhere. It’s tricky to write code involving mutable structures and it’s easy to make subtle errors or get surprising results, so we suggest sticking with lists and strings unless you’re certain you want and need mutability.

Example

let dict table:make
table:put dict "turtle" "cute"
table:put dict "bunny" "cutest"
print dict
=> {{table: "turtle" -> "cute", "bunny" -> "cutest" }}
print table:length dict
=> 2
print table:get dict "turtle"
=> "cute"
print table:get dict "leopard"
=> (error)
print table:keys dict
=> ["turtle" "bunny"]

Primitives