create-turtles
is a primitive that creates a given number of new turtles in the model. These new turtles are all placed at the center of the model with the same default shape but with random colors and headings. The shorthand version of this primitive is crt
.
create-turtles 1015
crt 30
In addition, we can use the brackets () [ ]
) to immediately give some rules to our new turtles. For example, the following code would not only create 100 new turtles but also make all of these turtles green and make each one go to a random patch. This way, we would not need to use a separate ask
command.
create-turtles 100 [
set color green
move-to one-of patches
]
Things to keep in mind when using create-turtles
:
create-<breed>
format to create new turtles of a specific custom breed such as create-dogs 100
or create-buildings 5 [ set color gray ]
.observer
can create new turtles. You cannot use this primitive within an ask
primitive. For example, both ask chickens [create-eggs 1]
and ask patches [ create-plants 1 ]
would show an error message. If you need already existing turtles to create new turtles, you should use the hatch
primitive. If you need the patches to create new turtles, you should use the sprout
primitive.In the model example below, we use the create-turtles
primitive to create a landscape with a house, some plants, people, dogs, and clouds.
Once you mastered the crt
primitive, don't stop there. Check out the resources below to improve your NetLogo skills.
crt
primitive:turtles-own
Declare a variable that belongs to turtles.