Commands Affecting Turtles (Printable)
alive? [Observer,
Turtle]
Returns a boolean. If the
turtle is alive, it returns true. If the turtle is not alive it returns false.
alive?-of number
[Observer, Turtle]
Returns a boolean. If the
turtle with the given who number is alive, it returns true. If the turtle with
the given who number is not alive it returns false.
average-of-turtles [list of commands] [Observer, Turtle]
Returns the numerical average of the [list of commands] when evaluated accross all the turtles.
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.
cct-and-do, create-custom-turtles-and-do breed number [list of commands] [Observer]
Creates number turtles of
type breed and tells them to do [list of
commands].
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. grabs 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 grabbing 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.
median-of-turtles [list of commands] [Observer, Turtle]
Returns the median [list of commands]
when [list of commands]is evaluated for all turtles.
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.
mode-of-turtles [list of commands] [Observer, Turtle]
Returns the mode of the given [list of commands] when run over all the turtles.
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.
one-of-turtles-with [condition] [list of commands] [Observer,
Turtle]
Chooses a turtle based on the following [condition]
and runs the commands specified in [list of commands]
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.
repeat number [list of commands] [Observer,
Turtle]
Do [list of commands] number times.
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.
sdev-of-turtles [list
of commands] [Observer, Turtle]
Returns the standard deviation of the [list of commands] when evaluated accross all the turtles.
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.
setshape
shape-name [Turtle]
Turtles set their shape to shape-name.
Note: shape-name can be the number of the shape as well.
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 ilistin 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.
variance-of-turtles [list of commands] [Observer, Turtle]
Returns the variance of [list of commands] amongst all the
turtles.
who [Turtle]
Returns the ID number of the turtle
who-max-of-frogs [list of commands] [Observer, Turtle]
Returns a list with the who number of the turtle of
breed frogs corresponding to the highest value of [list of commands] along with
the highest value of [list of commands].
who-max-of-frogs-with [condition] [list of commands] [Observer,
Turtle]
Returns a list with the who number of the turtle of
breed frogs which satifies the [condition] and has
the highest value of [list of commands] along with the highest value of [list
of commands].
who-max-of-turtles [list of commands] [Observer, Turtle]
Returns a list with the who number of the turtle corresponding
to the highest value of [list of commands] along with the highest value of [list
of commands].
who-max-of-turtles-with [condition] [list of commands] [Observer,
Turtle]
Returns a list with the who number of the turtle which
satifies the [condition] and has the highest value
of [list of commands] along with the highest value of [list of commands].
who-min-of-frogs [list of commands] [Observer, Turtle]
Returns a list with the who number of the turtle of
breed frogs corresponding to the smallest value of [list of commands] along
with the smallest value of [list of commands].
who-min-of-frogs-with [condition] [list of commands] [Observer,
Turtle]
Returns a list with the who number of the turtle of
breed frogs which satifies the [condition] and has
the least value of [list of commands] along with the smallest value of [list
of commands].
who-min-of-turtles [list of commands] [Observer, Turtle]
Returns a list with the who number of the turtle corresponding
to the smallest value of [list of commands] along with the smallest value of
[list of commands].
who-min-of-turtles-with [condition] [list of commands] [Observer,
Turtle]
Returns a list with the who number of the turtlewhich satifies the [condition]
and has the least value of [list of commands] along with the smallest value
of [list of commands].
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.