When I run my code, I sometimes get the following error:
stack overflow (recursion too deep)
error while observer running ASK
called by procedure GO
called by Button 'go'
This only happens intermittently and I'm not sure what causes it.
to go
ask cars [
speed-up
fd speed
if([pcolor] of patch-ahead 1 = yellow)
[stay]
]
tick
end
to speed-up
let car-ahead one-of turtles-on patch-ahead 3
ifelse car-ahead != nobody
[ slow-down-car car-ahead ]
[ speed-up-car ]
if speed < speed-min [ set speed speed-min ]
if speed > speed-limit [ set speed speed-limit ]
fd speed
separate-cars
end
to separate-cars ;; turtle procedure
if any? other turtles-here [
fd 3
separate-cars
]
end
to stay
set speed 0
ask cars
[
ifelse count-up = 0 [speed-up
fd speed
set color green
] [ set count-up count-up - 1
stay ]
]
end
to slow-down-car [ car-ahead ] ;; turtle procedure
;; slow down so you are driving more slowly than the car ahead of you
set speed [ speed ] of car-ahead - deceleration
end
to speed-up-car ;; turtle procedure
set speed speed + acceleration
end
Related
I want to let move my turtles forward, if there are no other turtles on patch ahead 1 with the same heading. the turtles slow down at some point until they don't move anymore and there are no turtles in front of them, but I don't know why.
Here is some code I have:
to movefd
ask turtles [
let car-ahead turtles-on patch-ahead 1
ifelse car-ahead with [heading = [heading] of myself] != nobody
[ slow-down-car ]
[ speed-up-car ]
if speed < speed-min [ set speed speed-min]
if speed > speed-limit [ set speed speed-limit ]
fd speed
]
end
to slow-down-car
set speed (speed - deceleration)
end
to speed-up-car
set speed speed + acceleration
end
I think (but am not sure as I can't test) that your problem is coming from the difference between agentsets and agents. The report turtles-on returns a turtleset, which can have any number of turtles. Even if it returns exactly one turtle, it returns that as a set of one turtle rather than as a turtle. On the other hand, nobody is a turtle, not a turtleset. A set can never be the same as a turtle.
Try this (note, I also changed 'car' to 'cars' as a reminder that it's a set):
ask turtles [
let cars-ahead turtles-on patch-ahead 1
ifelse any? cars-ahead with [heading = [heading] of myself]
[ slow-down-car ]
[ speed-up-car ]
...
]
end
Recently I've been working on netlogo especially at Traffic Basic.
I want to modify the code and make a function to calculate distance between every turtle (car) with the one ahead of them.
How can I do this?
Maybe a to-report will do what you want. If you add this procedure to Traffic Basic:
to-report distance-car-ahead
; If there are any cars within 10 patches of me
ifelse any? other turtles in-cone 10 1 [
; Report the distance to the nearest one
report distance ( min-one-of ( other turtles in-cone 10 1 ) [distance myself] )
] [
; Otherwise, report that I am in the lead
report "I am the lead car"
]
end
Now as an example, you can modify go to check that this is working, like so:
to go
;; if there is a car right ahead of you, match its speed then slow down
ask turtles [
let car-ahead one-of turtles-on patch-ahead 1
ifelse car-ahead != nobody
[ slow-down-car car-ahead ]
[ speed-up-car ] ;; otherwise, speed up
;; don't slow down below speed minimum or speed up beyond speed limit
if speed < speed-min [ set speed speed-min ]
if speed > speed-limit [ set speed speed-limit ]
fd speed
show distance-car-ahead
]
tick
end
I recommend turning the number of cars down to 3 or 4 to evaluate the print statements to make sure it's doing what you expect.
I am trying to simulate a robotic lawn mower on Netlogo. My first goal was it finds its way home to recharge itself when the battery is low.
This is now done (thanks Luke !) but I can't figure how to make the lawnmower stop when it reaches the house (it keeps moving 2 patches around). Therefore my energy slider goes infinitely below zero.
I first thought of adding an event "recharge" and placing it after "check death" in to go with a if instance. But :
How do I say if car goes on specific patch : stop and get energy ? Should I use a special patch color for the house and then code if car goes on blue patch..... ?
Could adding the recharge event at the end of the to go elements would possibly create a conflict because recharge only goes when on low battery ? Would putting it in check death be a solution ?
Then I would like it to go back to work after instant recharge.
Any ideas ?
Here's the code :
breed [cars car]
cars-own [target]
breed [houses house]
to setup
clear-all
setup-patches
setup-cars ;;represent lawn mower
setup-house
reset-ticks
end
to setup-patches
ask patches [set pcolor green] ;; Setup grass patches
ask patches with [
pxcor = max-pxcor or
pxcor = min-pxcor or
pycor = max-pycor or
pycor = min-pycor ] [
set pcolor red ;; Setup the borders of the garden
]
end
to setup-cars
create-cars 1 [
setxy 8 8
set target one-of houses
]
end
to setup-house
set-default-shape houses "house"
ask patch 7 8 [sprout-houses 1]
end
to place-walls
if mouse-down? [
ask patch mouse-xcor mouse-ycor [ set pcolor red ]
display
]
end
to go
move-cars
cut-grass
check-death ;; Check % battery.
tick
end
to move-cars
ask cars
[
ifelse [pcolor] of patch-ahead 1 = red
[ lt random-float 360 ] ;; see red patch ahead turn left.
[ fd 1 ] ;; otherwise it is ok to go.
set energy energy - 1
]
tick
end
to cut-grass
ask cars [
if pcolor = green [
set pcolor gray
]
]
end
to check-death ;; when low energy lawn mower will go back to house
ask cars [
ifelse energy >= 150
[ set label "Energy ok" ]
[ set label "Low Energy, returning to base"
set target min-one-of houses [distance myself]
face target
ifelse distance target < 1
[ move-to target ]
[ fd 1 ]
]
]
end
You can use a logical flag (eg charging?) in conjunction with a counter (eg charge-time) to do this. Try modifying your cars-own definitions like this:
cars-own [target charging? charge-time]
and setup-cars like this:
to setup-cars
create-cars 1 [
setxy 8 8
set target one-of houses
set charging? false
]
end
Then you can have the mower do different things based on whether charging? is true or false. Try modifying your move-cars and check-death to accommodate these changes (side note- you've got a tick in both go and move-cars):
to move-cars
ask cars [
ifelse charging? [
set charge-time charge-time + 1
if charge-time > 14 [
set energy 200
set charging? false
set charge-time 0
]
] [
ifelse [pcolor] of patch-ahead 1 = red
[ lt random-float 360 ] ;; see red patch ahead turn left.
[ fd 1 ] ;; otherwise it is ok to go.
set energy energy - 1
]
]
end
to check-death ;; when low energy lawn mower will go back to house
ask cars [
ifelse energy >= 150
[ set label "Energy ok" ]
[ set label "Low Energy, returning to base"
set target min-one-of houses [distance myself]
face target
ifelse distance target < 1
[ move-to target
set charging? true
]
[ fd 1 ]
]
]
end
I suggest you change energy a turtle variable like car-energy so that the turtles values are independent of your slider. That would mean you could have multiple mowers and they could reset their energy level to the slider setting once they are charged! You would just include a line like
set car-energy energy
in your setup-cars (and then modify so that energy in your car procedures is instead car-energy).
Readers,
I'm a beginner in NetLogo. Please help me in solving few issues with my code that is below:
I'm getting an error "You can't use tick in a turtle context, because tick is observer-only.
I need to get tick value updated after each turtle go all three of "arrive-reception, arrive-triage, go-drroom".
the rest of people is not moving around the arrive reception, arrive triage is running.
to setup-people
set-default-shape turtles "person"
set destination ( patch-set patch -2 34 patch 8 34 )
create-turtles uninfected
[ set color blue
allocate-turtles
]
create-turtles infected
[ set color red
allocate-turtles
]
end
to allocate-turtles
if (pcolor = 9.9 and any? turtles-here)
[
set size 1.5
set heading 0
setxy int random-xcor int random-ycor
]
end
to go
move-people
arrive-reception
arrive-triage
go-drroom
tick
end
to move-people
ask turtles [
rt 360
forward 1
]
end
to arrive-reception
ask n-of (random count turtles) turtles
[
if windows = 1
[
move-to patch -2 34
ifelse not any? turtles-here
[ wait wait-time ]
[ wait-in-queue ]
]
]
end
to wait-in-queue
set arrival-time ticks
bk 1
if any? other turtles-here
[ wait-in-queue ]
wait wait-time
if ticks - arrival-time > wait-time
[ set arrival-time 0
fd 1 ]
end
to arrive-triage
if triage = "Open"
[
move-to patch 26 11
if any? other turtles-here
[ wait-in-queue]
wait wait-time
move-to one-of patches with [pcolor = 109 and not any? other turtles-here ]
wait wait-time
]
end
to go-drroom
move-to one-of patches with [pcolor = 128]
if ( min-one-of other turtles in-radius 5 [distance myself] != nobody)
[
move-to one-of patches with [pcolor = 129]
if ( min-one-of other turtles in-radius 5 [distance myself] != nobody)
[
move-to one-of patches with [pcolor = 5]
if any? seats with [turtles = nobody]
[
move-to one-of max-n-of 6 neighbors [seats]
]
]
]
wait wait-time
die
end
Thanks.
First, some basic programming tricks - don't write so much before trying to debug. If you make a small change and check it, then it's easy to work out where the error is. The first draft of a procedure can be as simple as:
to go-drroom
end
and then fill in the details of what happens in the procedure later.
Typically this error is because you forgot to close a bracket somewhere. That is, one of the procedures starts with ask turtles [ ... and there is no ] so NetLogo is still thinking that the code applies to turtles. However, I can't see an obvious missing ].
But you do have a conceptual problem. The term context is used in NetLogo to refer to who is asking the code to be done and to whom. So ask turtles [ forward 1] is the observer asking the turtles to move and is an observer context procedure. You are not thinking about what context you are in when writing the procedures, and this is probably what is setting off your error.
In the go procedure, you first call move-people. This does ask turtles [ ] so is (appropriately) from the observer context. Then you call arrive-reception and it is also okay.
But then you call arrive-triage and go-drroom still from the observer context and have commands like move-to. Who is being asked to move? You don't have ask turtles .... On the other hand, the procedure wait-in-queue has commands like move-to, but it is fine because it is only called from within an ask turtles ... in the arrive-reception procedure.
I'm trying to model the avoidance of animal agents from human agents in NetLogo. First, I asked a single predator to avoid people using two behaviors, "wary" and "scared". This worked nicely. But then I asked the prey animals (168 individuals right now but potentially many more) to do the same and the model has slowed down to a snail's pace. As I'm pretty new to NetLogo I'm sure that there is a more efficient way to code this behavior. Any suggestions on how to streamline this process? I'm sure there is a better way to do it. Thanks!
to avoid-people ;; test if people too close to predator and prey and animals moves away if is.
ask predator [
ifelse ticks mod 24 >= 5 and ticks mod 24 < 18 [ ;makes sure the animals respond to people during the daytime
humans-near
ifelse any? wary
[ fd 0 ]
[ ]
humans-too-near
if any? scared
[run-away]
] [set wary 0 set scared 0]]
ask preys [
ifelse ticks mod 24 >= 5 and ticks mod 24 < 18 [
humans-near
ifelse any? wary
[ fd 0 ]
[ ]
humans-too-near
if any? scared
[run-away]
] [set wary 0 set scared 0]]
end
;;Humans-near and humans-too-near are functions
;;Alert-distance and flight initiation distance are sliders for the predator but are set values for prey
to humans-near ;;adds all humans in alert-distance radius of animal to an agent subset for that agent.
ask predator [
set wary humans in-radius alert-distance]
ask preys [
set wary humans in-radius 10]
end
to humans-too-near ;;adds all humans in flight-initiation-distance radius of animal to an agent subset for that agent.
ask predator [
set scared humans in-radius flight-initiation-distance]
ask preys [
set scared humans in-radius 5]
end
to run-away ;;Make animal avoid the human closest to it.
set nearest-human min-one-of scared [distance myself]
turn-away ([heading] of nearest-human) max-separate-turn
end
;;this keeps the animals inside the tropical forest and away from human settlement.
;;Max-separate-turn is a slider dictating the angle that the predator runs away from the human
to turn-away [new-heading max-turn]
turn-at-most (subtract-headings heading new-heading) max-turn
ifelse [habitat = typeTrop] of patch-ahead run-distance
[fd run-distance] [turn-away ([heading] of nearest-human) max-separate-turn]
end
to turn-at-most [turn max-turn]
ifelse abs turn > max-turn
[ ifelse turn > 0
[ rt max-turn ]
[ lt max-turn ] ]
[ rt turn ]
end
I did not understand your code, but this is one way to do what you want, I am not sure how agents should behave if they are scared or they move with wary, but you can change these easily :
Breed [predators predator]
Breed [Humans Human]
Breed [Preys Prey]
turtles-own [
wary
scared
]
to setup
Clear-all
Create-humans 5 [Set color orange set shape "person" move-to patch random 30 random 30]
Create-Preys 5[Set color white Set shape "Sheep" move-to patch random 30 random 30]
Create-predators 5 [set color red Set shape "wolf" move-to patch random 30 random 30]
ask turtles
[set Wary false
Set Scared False
]
reset-ticks
end
to go
ask turtles
[rt random 5
fd 0.3]
avoid-people
tick
end
to avoid-people
ifelse is-day?
[
ask predators
[ if humans-near?
[
set wary true
if humans-too-near? [Set Scared true]
set label (word wary "," Scared )
]
]
Ask Preys
[ if humans-near?
[
set wary true
if humans-too-near? [Set Scared true]
set label (word wary "," Scared )
]
]
]
[; what they should do when its night time
]
end
to-report humans-too-near?
report any? humans in-radius 2
end
to-report humans-near?
report any? humans in-radius 5
end
to-report is-day?
report (ticks mod 24 >= 5 and ticks mod 24 < 18)
end
*Update:
Your problem was in having 2 ask inside each other , I am glad your model now runs faster.