Commands Affecting Turtles (Printable)
bk, back number
[Turtle]
Turtles move number
steps backward
breed [Turtle]
Returns the turtle's breed.
breed-at xcor ycor
[Observer, Turtle]
Reports the breed of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller.
breed-of number
[Observer, Turtle]
Reports the breed of the turtle with ID Number number
.
breed-towards angle distance
[Observer, Turtle]
Reports the breed of the turtle distance
away at an angle of
angle
.
color [Turtle]
Returns the color of the turtle.
color-at xcor ycor
[Observer, Turtle]
Reports the color of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller .
color-of number
[Observer, Turtle]
Reports the color of the turtle with ID Number number
.
color-towards angle distance
[Observer, Turtle]
Reports the color of the turtle distance
away at an angle of angle
.
count-color color
[Observer, Turtle]
Returns the number of turtles that are the color color
.
count-turtles [Observer, Turtle]
Returns the number of turtles.
count-turtles-at xcor ycor
[Observer, Turtle]
Returns the number of turtles xcor
units in the x direction and
ycor
units in the y direction away from the caller .
count-turtles-here [Turtle]
Returns the number of turtles sitting on the caller's patch
count-turtles-towards angle distance
[Observer, Turtle]
Returns the number of turtles distance
away at angle angle
.
count-turtles-with [ilist]
[Observer, Turtle]
Returns the number of turtles whose ilist
is true.
Sample usage: show count-turtles-with [(distance 0 0) < 5]
This gives thenumber of turtles inside a circle of radius 5 centered at the
origin.
create-and-do, create-turtles-and do number ilist
[Observer]
Creates number
turtles and tells them to do ilist
.
crt, create-turtles number
[Observer]
Creates number
turtles.
ct [Observer]
Clears (kills) all of the turtles.
die [Turtle]
Turtles die, meaning that they stop running all code and disappear forever.
distance xcor ycor
[Observer, Turtle]
Returns the distance from the caller to (xcor,ycor
).
distance-nowrap xcor ycor
[Observer, Turtle]
Returns the distance from the caller to xcor ycor
without wrapping.
dx [Turtle]
Returns the x-coordinate one step forward from the turtle's current position.
dy [Turtle]
Returns the y-coordinate one step forward from the turtle's current position.
fd, forward number
[Turtle]
Turtles move number
steps forward.
grab ilist
[Observer, Turtle]
Allows the observer or a turtle to instruct another turtle or group of turtles
(specified by turtle_number
or a dlist of turtle_numbers
)
to perform ilist. The ID of the turtle(s) is stored in partner
if there is one turtle being grabbed, in partners
if there are
many. grab
s can be nested within each other. If the specified turtle
does not exist, the caller skips ilist
and continues. If you call
a procedure within ilist
, you are still grab
bing the
turtles. A turtle may not grab
itself. A turtle already being grabbed
by one turtle cannot be grabbed by another.
hatch ilist
[Turtle]
Turtles make exact copy of themselves, tell them to run ilist
.
Note: Turtles will not run forever buttons while running ilist
.
heading [Turtle]
Returns the direction that the turtle is facing.
heading-at xcor ycor
[Observer, Turtle]
Reports the heading of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller.
heading-of number
[Observer, Turtle]
Reports the heading of the turtle with ID Number number
.
heading-towards angle distance
[Observer, Turtle]
Reports the heading of the turtle distance
away at an angle of
angle
.
home [Turtle]
Turtles go to coordinates (0,0). This is the same as using setxy 0 0.
ht, hideturtle [Turtle]
Turtles make themselves invisible.
jump number
[Turtle]
Turtles move number
steps in the time it takes to make one normal
step. For example, jump 15 and fd 1 both take the same amount of time to perform.
fd 15, however, would take 15 times as long as jump 15.
kill number
[Observer, Turtle]
Kills turtle with ID number number
.
leap number
[Turtle]
Turtles jump number
steps only if no other turtle is currently
on the patch they will land on.
list-of-turtles [Observer, Turtle]
Returns a list of turtles.
list-of-turtles-at xcor ycor
[Observer, Turtle]
Returns a list of turtles xcor
units in the x direction and ycor
units in the y direction away from the caller.
list-of-turtles-here [Turtle]
Returns a list of turtles on the caller's patch.
list-of-turtles-towards angle distance
[Observer,
Turtle]
Returns a list of turtles at the patch distance
away at angle
angle
.
list-of-turtles-with condition [Observer, Turtle]
Returns a list of turtles satisfying condition
.
lt, left number
[Turtle]
Turtles turn left by number
degrees.
max-of-turtles-with pred-ilist ilist
Reports the highest value of ilist
when run over the turtles
that satisfy pred-ilist
. If there are no turtles in which pred-ilist
is true, returns minnum
, the smallest number possible without going
into negative infinity. Note: This command can also be executed by patches,
for example within an ask-patches
statement.
min-of-turtles-with pred-ilist ilist
Reports the lowest value of ilist
when run over the turtles that
satisfy pred-ilist
. If there are no turtles in which pred-ilist
is true, returns maxnum
, the largest number possible without going
into positive infinity. Note: This command can also be executed by patches,
for example within an ask-patches
statement.
myself [Turtle]
During a count-turtles-with
command, myself
reports
the who number of the turtle which called it.
Example: count-turtles-with [(distance xcor-of myself ycor-of myself)
< 5]
counts all turtles within a radius of 5 units of the caller.
nobody [Observer, Turtle]
An alias for -1
one-of-turtles [Observer, Turtle]
Returns a random turtle.
one-of-turtles-at xcor ycor
[Observer, Turtle]
Returns a random turtle xcor
units in the x direction and ycor
units in the y direction away from the caller.
one-of-turtles-here [Turtle]
Returns a random turtle on the caller's patch other than the caller.
one-of-turtles-towards angle distance
[Observer, Turtle]
Returns a random turtle at the patch distance
away at angle angle
.
partner [Observer, Turtle]
Returns the ID number of the turtle being grabbed, or -1 if no turtle is being grabbed.
partners [Observer, Turtle]
Returns a dlist of the turtles being grabbed, or [ ] if no turtles are being grabbed.
pendown? [Turtle]
Returns true if the turtle's pen is down, otherwise false.
pendown?-at xcor ycor
[Observer, Turtle]
Reports whether the pen of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller is down.
pendown?-of number
[Observer, Turtle]
Reports whether the pen of the turtle with ID Number number
is
down.
pendown?-towards angle distance
[Observer, Turtle]
Reports whether the pen of a turtle distance
away at an angle
of angle
is down.
pu, penup [Turtle]
Turtles pick up their "pens," meaning that they no longer draw when they move.
rt, right number
[Turtle]
Turtles turn right by number
degrees.
scale-color color variable limit1 limit2
[Turtle]
Turtles set their color to a shade of color
based on their value
of variable
. limit1
and limit2
determine
the amount of gradation.
Example:
scale-color blue energy 0 20
Turtles turn one of twenty shades of blue. Turtles with lower energy turn darker
blue.
scale-color blue energy 20 0
Turtles turn one of twenty shades of blue. Turtles with lower energy turn lighter
blue.
setbreed breedname
[Turtle]
Turtles set their breed to breedname
.
setbreed-at xcor ycor breedname
[Observer, Turtle]
Sets the breed of the turtle xcor
units in the x direction and
ycor
units in the y direction away from the caller to breedname
.
See the breeds reference for more information.
setbreed-of number breedname
[Observer, Turtle]
Sets the breed of the turtle with ID Number number
to breedname
.
See the breeds reference for more information.
setbreed-towards angle distance breedname
[Observer,
Turtle]
Sets the breed of the turtle distance
away in the direction angle
to breedname
.
See the breeds reference for more information.
setc, setcolor colorname (or colornumber)
[Turtle]
Turtles set their color to colorname (or color number)
.
setc-at xcor ycor number
[Observer, Turtle]
Sets the color of the turtle xcor
units in the x direction and
ycor
units in the y direction away from the caller to number
.
setc-of number1 number2
[Observer, Turtle]
Sets the color of the turtle with ID number1
to color number2
.
setc-towards angle distance number
[Observer, Turtle]
Sets the color of the turtle distance
away if the heading was
angle
to number
.
seth, setheading direction
[Turtle]
Turtles set their heading to a direction
from 0 to 359 degrees.
seth-at xcor ycor number
[Observer, Turtle]
Sets the heading of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller to number
.
seth-of number1 number2
[Observer, Turtle]
Sets the heading of the turtle with ID number1
to number2
.
seth-towards angle distance number
[Observer, Turtle]
Sets the heading of the turtle distance
away if the heading was
angle
to number
.
setpendown?-at xcor ycor boolean
[Observer, Turtle]
Sets the pendown state of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller to boolean
.
setpendown?-of number boolean
[Observer, Turtle]
Sets the pendown state of the turtle with ID Number number
to
boolean
.
setpendown?-towards angle distance boolean
[Observer,
Turtle]
Sets the pendown state of a turtle distance
away at an angle of
angle
to boolean
.
setx, setxcor number
[Turtle]
Turtles set their x-coordinate to number
.
setxcor-at xcor ycor number
[Observer, Turtle]
Sets the x-coordinate of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller to number
.
setxcor-of number1 number2
[Observer, Turtle]
Sets the x-coordinate of the turtle with ID number1
to number2
.
setxcor-towards angle distance number
[Observer, Turtle]
Sets the x-coordinate of the turtle distance
away if the heading
was angle
to number
.
setxy number1 number2
[Turtle]
Turtles set their x-coordinate to number1
and y-coordinate to
number2
.
sety, setycor number
[Turtle]
Turtles set their y-coordinate to number
.
setycor-at xcor ycor number
[Observer, Turtle]
Sets the y-coordinate of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller to number
.
setycor-of number1 number2
[Observer, Turtle]
Sets the y-coordinate of the turtle with ID Number number1
to
number2
.
setycor-towards angle distance number
[Observer, Turtle]
Sets the y-coordinate of the turtle distance
away if the heading
was angle
to number
.
shown? [Observer, Turtle]
Returns true if the turtle is currently visible, otherwise false.
shown?-at xcor ycor
[Observer, Turtle]
Reports whether the turtle at (xcor ycor
) is visible.
shown?-of number
[Observer, Turtle]
Reports whether the turtle with ID number
is visible.
shown?-towards angle distance
[Observer, Turtle]
Reports whether the turtle distance
away at an angle of angle
is visible.
sprout list to run
[Observer, Turtle]
Each patch creates a turtle, which then executes list to run
.
NOTE: This is a patch command. It must be called from within an ask-patches
or ask-patch-at
statement.
st, showturtle [Turtle]
Hidden turtles make themselves visible.
stamp color
[Observer, Turtle]
Sets color of patch under turtle to color
stamp-at xcor ycor color
[Observer, Turtle]
Sets the color of the patch xcor
units in the x direction and
ycor
units in the y direction away from the caller to color
.
stamp-towards angle distance color
[Turtle]
Sets the color of the patch distance
away, if the heading were
angle
, to color
.
step [Turtle]
A synonym for fd 1
.
sum-of-turtles ilist
[Observer, Turtle]
Reports the total of evaluating ilist
in every turtle and adding
it up.
Example usage:
show sum-of-turtles [weight * weight]
This gives the sum of every turtle's (weight squared).
sum-of-turtles-with pred-ilist ilist
Reports the total value of ilist
when run over the turtles that
satisfy pred-ilist
. If there are no turtles in which pred-ilist
is true, returns 0. Note: This command can also be executed by patches, for
example within an ask-patches
statement.
Example: sum-of-turtles-with (color = red) [age]
returns the sum
of the ages of all the red turtles.
towards xcor ycor
[Observer, Turtle]
Returns the angle from the callers xcor and ycor to the specified absolute
position specified by xcor
and ycor
.
towards-nowrap xcor ycor
[Observer, Turtle]
Returns the angle from the callers xcor and ycor to the specified absolute
position specified by xcor
and ycor
without wrapping.
who [Turtle]
Returns the ID number of the turtle
xcor [Turtle]
Returns the x-coordinate of the turtle
xcor-at xcor ycor
[Observer, Turtle]
Reports the x-coordinate of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller.
xcor-of number
[Observer, Turtle]
Reports the x-coordinate of the turtle with ID number
.
xcor-towards angle distance
[Observer, Turtle]
Reports the x-coordinate of the turtle distance
away if the heading
was angle
.
ycor [Turtle]
Returns the y-coordinate of the turtle
ycor-at xcor ycor
[Observer, Turtle]
Reports the y-coordinate of the turtle xcor
units in the x direction
and ycor
units in the y direction away from the caller.
ycor-of number
[Observer, Turtle]
Reports the y-coordinate of the turtle with ID number
.
ycor-towards angle distance
[Observer, Turtle]
Reports the y-coordinate of the turtle distance
away if the heading
was angle
.