How to limit number of turtles in a patch in NetLogo - netlogo

I want to limit number of turtles per patch. I thought if I restrict movement of turtles as per the (1) and (2) conditions it will limit number of turtles per patch but whatever code I tried for this till now did not worked.
Let's suppose there are five turtles on patch Y and five is the limit.
1) to ask turtles standing at front on patch X (refer figure) to stop moving till there are five turtles on patch Y (refer figure).
2) to ask turtles standing at front on patch Y to move forward to patch z (refer figure) if patch z has less than five(5) turtles on it else stop.
At last I am using following simple code
let turtles-ahead other turtles in-cone speed 90
let turtle-ahead min-one-of turtles-ahead [distance myself]
ifelse turtle-ahead != nobody
[
set speed [speed] of turtle-ahead
slow-down
]
[speed-up]
This code simply ask turtles to move one-behind-another pattern or queue but it does not help me to limit number of turtles per patch whatever limit may be 4,5,6,7, 8... I have sprouted turtles within "go" procedures (1 turtle per patch, as per my need). The turtles are sprouted on a defined set of patches not in the whole world. So slowly number of turtles starts increasing and move around the world and after certain amount of ticks they are ask to exit out of the defined area and they die. Now at times it shows 10,11,.... 37 or above turtles on certain patches and this I want to stop actually.
I have checked one-turtles-per-patch, other code examples and many other helps from internet but no results.
For any other idea or help I would be obliged. Please help me.

I think you want to have turtles assess the count of turtles-here of the patch to which they are trying to move. Consider this simple example:
to setup
ca
ask n-of 15 patches with [ pycor = 0 ] [
sprout 3 [
set heading 90
]
]
reset-ticks
end
to go
ask turtles [
if ( count [turtles-here] of patch-ahead 1 ) < 5 and xcor < 16 [
fd 1
]
]
print [count turtles-here] of patches with [ any? turtles-here ]
tick
end
On each tick, the turtles with an xcor of less than 16 (just to set a stop for this example) all check the patch-ahead 1 for the count of turtles on that patch. If the count is less than 5, the turtle moves to that patch. Otherwise, the turtle does nothing.

Related

Is there a way to kill a certain number of turtles within a radius of a patch with a certain color in Netlogo?

I am very new to Netlogo and I am trying to simulate culling of turtles within a certain region based on the characteristics of the patch. Within my model landscape, I have one single patch that is orange. I want 50% of turtles within 5 pixels of that patch to die. I would also like this process to continue every year after the first year of the simulation (this part I think I have). Can anyone help me?
if d = 10 [
if year >= 2 [
let ring nobody
set ring patches in-radius 5 patches with [pcolor = orange]
ask turtles-on ring [die]
]
]
in-radius reports agents that are within a certain distance from the caller, so the orange patch must be the one calling in-radius.
The code in your example is not reproducible, so I'll make an arbitrary example:
to setup
clear-all
ask one-of patches [
set pcolor orange
]
create-turtles 100 [
setxy random-xcor random-ycor
]
end
to go
ask patches with [pcolor = orange] [
ask turtles-on patches in-radius 5 [
if (random 2 < 1) [die]
]
]
end
Note that in-radius reports agents within a certain distance, where the unit of measure of distance is a patch`s side.
Identifying patches within a certain distance and then asking all turtles on those patches to die (as in the example above, which follows the approach in your question) has a different effect than asking all turtles within a certain distance to die.
Which of the two approaches fits your case is something that you have to decide. Below, the code that would address turtles directly:
to go
ask patches with [pcolor = orange] [
ask turtles in-radius 5 [
if (random 2 < 1) [die]
]
]
end

NetLogo: calculate distance to other turtles and make them dissatisfied if another turtle is too close

I sprouted my turtles over the patches and in the 'go' I want each turtle to calculate if another turtle is too close (based on a certain threshold of X meters/patches). If another turtle is too close, i want the turtle to become 'dissatisfied'.
Movements of the turtles are not required.
What is the best way to do this? The only piece of code for the go procedure I have so far is as follows:
to go
ask n-of initial-number-tourists (patches with [ lagoon_proximity = 1])
[
sprout 1 [
set color black
set size 10
]
]
tick
end
Kind regards!
Your code is creating more turtles and doesn't have anything about checking distances so it is not clear how it is related to the problem you are trying to solve. However, the following code measure the distance to the nearest turtle and prints a message if that is less than 5.
ask turtles
[ let nearest min-one-of turtles [distance myself]
if distance nearest < 5 [ show "I feel crowded" ]
]

NetLogo: how to let turtles return after one tick

hope you can help me out! I have a NetLogo question about the following code:
breed [tourists tourist]
turtles-own [satisfaction]
to setup
clear-all
reset-ticks
end
to go
tick
ask n-of initial-number-tourists patches
[
sprout 1 [
set color white
set size 1
]
]
ask turtles
[ let nearest min-one-of turtles [distance myself]
if-else distance nearest < 0.0000001 [ set satisfaction 0 ]
[ set satisfaction 1 ]
]
ask turtles with [satisfaction = 0] [die]
end
The intention is to sprout "initial-number-tourists" at the start of each tick. Then, they calculate their 'satisfaction' based on the if there are turtles close and let the turtles that have a satisfaction of 0 die. Then, the turtles that remain (that are satisfied) will be sprouted again and their satisfaction will be calculated again.
The code is working, however, with unexpected outcomes. What happens is that the turtles are all sprouted, and they all die each tick. The next tick; they are sprouted again and all die again. Even if i set the distance threshold really low like i did in the code I provided.
Hopefully you can help me out!! Kind regards
The problem you are encountering is that the nearest turtle to each turtle is itself! Thus the distance to nearest is always zero and satisfaction will be set to zero for every turtle. What you want is the closest among the other turtles,
let nearest min-one-of other turtles [distance myself]
(Your distance threshold will mean that all turtles will have satisfaction of 1, but I assume that is what you wanted to accomplish in your testing. Since turtles are sprouted at the centers of the patches, a threshold of < 1.0 would accomplish the same thing.)
Minor point: the convention is to put tick at the end, not the beginning of the go procedure.

Comparing patches

I want to compare the patches in a certain radius regarding the amount of a certain class of agents on them. The agents should move to the patch where the most agents (in this case humans) are. If they are already on the patch with the most humans then they must not move. I coded it and the humans group but most of them don't stay and run around in lines (one behind the other). Would be great if anyone of you could have a quick look at my code. Thanks
if Strategy = "Gathering-Simple" [
if ((count(humans-on max-one-of patches in-radius rad [count(humans-here)] )) ) >= count(humans-here) [
if count(humans-on patches in-radius rad) - count(humans-here) > 0 [
face max-one-of patches in-radius rad [count(humans-here)]
fd 1
]]
]
This is a complete working example that uses your code. Is this displaying the behaviour you mean? It does have turtles chasing each other.
to setup
clear-all
create-turtles 100 [ setxy random-xcor random-ycor ]
reset-ticks
end
to go
let rad 5
ask turtles
[ let target-patch max-one-of patches in-radius rad [count turtles-here]
if count turtles-on target-patch >= count turtles-here ; comment 1
[ if count turtles-on patches in-radius rad > count turtles-here ; comment 2
[ face target-patch
forward 1
]
]
]
tick
end
If so, have a look at the two lines I have comments on.
Comment 1: The >= means that, even if the turtles are already on the highest count patch, this condition will be satisfied because count turtles-here will be equal to the count of the turtles on the highest count patch (this patch).
Comment 2: This line means that as long as there are any turtles on any patch within the radius but not on the particular patch where the asking turtle is located, then the turtle will move forward.
If you want to only have turtles move if not on a maximum count patch, try this instead:
to setup
clear-all
create-turtles 100 [ setxy random-xcor random-ycor ]
reset-ticks
end
to go
let rad 5
ask turtles
[ let target-patch max-one-of patches in-radius rad [count turtles-here]
if count turtles-on target-patch > count turtles-here
[ face target-patch
forward 1
]
]
tick
end
I took out the = in the comment 1 line and removed the second condition entirely so now the turtles move if their current patch has fewer (strictly, not <=) turtles than the patch they've spotted.
I agree with the previous post, but have some additional information.
If you want to move entirely to the target patch on each iteration, instead of moving just one step towards the target patch, in the above answer you could replace the code which produces one step of motion
[ face target-patch
forward 1
]
with
[
move-to target-patch
]
I confirmed by experimentation that the results of the two methods of moving will produce similar but somewhat different results.

NetLogo: Combine and form a new turtle

I am currently learning NetLogo and I need help. In my model I have same sized 10 turtles which moves randomly. When 2 or more turtles are on the same patch they will combine and form a new turtle with the double size. In this manner, the main rule is max. 5 turtles can combine to each other. And this formation will continue until the there will be 2 turtles (with each contain 5 turtles) remain.
I had created turtles and made them move randomly, but I could not managed to combine them. Can you show me a way to do this? Any help appreciated. Regards.
EDIT: I tried the "in-radius" command unsuccessfully. 5-5 distribution of the turtles (as you can can see from the code, they represent H2O molecules) is vital for the system definition and any other distributions are not allowed in the model.
In detail, when randomly moving 2 H2O molecules meet on the same patch, they will combine to form a new molecule (2H2O). The main rule is as previously mentioned, max. 5 molecules can combine which ends with forming 5H2O. Since, initially there are 10H2O molecules in the system, there will be 2 5H2O molecules at the end.
The code I tried to implement is as follows,
breed [h2o-molecules h2o]
to setup
clear-all
reset-ticks
create-h2o-molecules h2o-num [
set color 105
set sIze .5
set shape "circle"
setxy random-xcor random-ycor
set pen-mode "up"
]
end
to setup-patches
ask patches [set pcolor 0]
show count turtles
end
to set-label
ask patches [
ifelse count turtles-here > 0
[set plabel count turtles-here]
[set plabel ""]
]
end
to move-h2o-molecules
ask h2o-molecules [
let dice random 1000
let change (dice - 1)
forward 2
set HEADING (HEADING + change * 2)
]
end
to go
setup-patches
move-h2o-molecules
ask turtles [rt random 1
fd 0.3]
set-label
tick
end
Thanks for your time and patience. Regards,
Using turtles-here
You don't need to ask patches for turtles-here (as you did to set patches labels). The function runs as well if called by a turtle (and is more efficient when there are more patches than turtles). But take care to use other turtles-here if you don't want to include the calling turtle.
Combine procedure
If you declare
a turtle variable after your breed declaration:
h2o-molecules-own [
turtles-inside
]
(set the variable value inside your create-h2o-molecules)
and your combination limit max-inside as a global variable (use slider widget with 5 as default value)
then the combine procedure can look like:
to combine ;; turtle procedure
; take one turtle from the same patch as a target
; which has turtles-inside low enough to combine with
let target one-of other h2o-molecules-here with
[turtles-inside <= max-inside - [turtles-inside] of myself]
if target != nobody
[
set turtles-inside turtles-inside +
[turtles-inside] of target ;; increase turtles-inside
ask target [ die ] ;; kill the target
set size sqrt turtles-inside ;; increase size
]
end
Stop
You can stop the simulation by
if not any? h2o-molecules with [turtles-inside < max-inside] [ stop ]
Comment
The condition used to select the target turtle is using turtles-here, other and the maximum constraint which is compared to the sum of turtles inside the target and turtles inside the calling turtle (using myself function).