I'm very new at Netlogo and programming in general.
I want to create a netlogo model, with female and male turtles. Both populations move through the world via random walk. The female population should find a partner and has the property 'radius'. Her own radius should expand if she has not found a partner until the moment she finds one. How can I program a radius around the female turtles, that expand after each time step if she has not found a partner?
Thanks for your help!
First, you need a turtle attribute that stores the value for each turtle. The way to do that is with a turtles-own statement. Then you simply change the value as required. The primitive in-radius looks at everything within the specified distance, and then you can set a condition by whether there are any? suitable mates. Your code would look something like (this is a complete model):
turtles-own
[ search-radius
mate
]
to setup
clear-all
create-turtles 20
[ setxy random-xcor random-ycor
set color blue
set search-radius 1
]
reset-ticks
end
to go
check-for-mate
tick
end
to check-for-mate
ask turtles with [color = blue]
[ let candidates other turtles in-radius search-radius
ifelse any? candidates
[ set mate one-of candidates
set color red
]
[ set search-radius search-radius + 0.5 + random-float 1
]
]
end
Related
I am new in using NetLogo, so I hope you can help me with this code.
I would like to build a network with two subnetwork, A and B, where A has N nodes and B beta*N nodes, where beta=0.5. Each network should be initialised with five fully connected nodes. I need to add a new node at a time, assuming that each has fixed out-degree k. Once a new node i comes into the network, it links to a randomly selected target node j. The other remaining k-1 nodes should be selected as following: with probability p, i should be linked to a random node of j's; with probability 1-p, i should be connected to another randomly selected node in A.
On the other hand, the nodes in B should be linked (directed link) to each node in A with probability P. P can vary from 0 to 1.
What I already tried is built the two networks with N and alpha*N nodes respectively. But, as I said, I am new in using NetLogo and I am finding many difficulties to build this network that should be really easy in a different programming language, I would be more familiar with.
; Global variables
breed [agents agent]
breed [bagents bagent]
to setup
clear-all
setup-agent
setup-bagent
end
; Defining agents
to setup-agent
set-default-shape turtles "person" ; agent shape
create-agents n-of-agents ; # of agents
[set size 2 ; agent size
set color white
setxy (random-xcor) (random-ycor)
]
; Random Network
ask agents [create-link-with one-of other agents with [not link-neighbor? myself]
ask links [set color white]
]
end
; Defining bagents
to setup-bagent
set-default-shape turtles "circle" ; bagents shape
set beta=0.5
let n-of-bagents beta*n-of-agents
create-bagents beta*n-of-agents ; # of bagents
[set size 2 ; bagent size
set color red
setxy (random-xcor) (random-ycor)
; Network
ask bagents [create-link-with one-of other bagents with [not link-neighbor? myself]
ask links [set color yellow]
]
end
to go
end
I hope you can help me to understand how to build such a network in NetLogo.
Many thanks
This does what you said. I don't think it's actually what you want as your algorithm is much better but still somewhat confused. But hopefully this gets you on the correct path.
UPDATED to make one node add each tick
globals
[ beta
prob
k
]
breed [A-agents A-agent]
breed [B-agents B-agent]
to setup
clear-all
set beta 0.5
set prob 0.2
set k 3
setup-A-seed
setup-B-seed
reset-ticks
end
to go
add-A-node
if random-float 1 < beta [add-B-node]
tick
end
; Defining A seed network
to setup-A-seed
create-A-agents 5
[ set shape "person"
set size 2
set color white
setxy random-xcor random-ycor
]
ask A-agents
[ create-links-to other A-agents
[ set color white ]
]
end
; Defining B seed network
to setup-B-seed
create-B-agents 5
[ set shape "circle"
set size 2
set color red
setxy random-xcor random-ycor
]
ask B-agents
[ create-links-to other B-agents
[ set color yellow ]
]
end
to add-A-node
create-A-agents 1
[ set shape "person"
set size 2
set color white
setxy random-xcor random-ycor
let target one-of other A-agents ; target is j in description
create-link-to target
repeat k - 1
[ let candidates (other [link-neighbors] of target) with [not link-neighbor? myself]
ifelse random-float 1 < prob or not any? candidates
[ create-link-to one-of other A-agents with [not link-neighbor? myself]
[ set color white ]
]
[ create-link-to one-of candidates
[ set color white ]
]
]
]
end
to add-B-node
create-B-agents 1
[ set shape "circle"
set size 2
set color red
setxy random-xcor random-ycor
let thisB self
ask A-agents
[ if random-float 1 < prob
[ create-link-from thisB
[ set color yellow
]
]
]
]
end
Some of the NetLogo issues I noticed in your code:
NetLogo does not use = for set
you must have space around mathematical operators (or NetLogo will think it's part of the name)
Some of the things you need to think about in your algorithm:
why do you have an initial B network if all Bs connect to each A with fixed probability?
what do you do if the selected A doesn't have any edges to follow?
As general advice, don't try writing something this complicated in one piece. Create your seed networks with 5 fully connected nodes. Make that work. Then do network A and make that work. Then bring in B. This iterative building is important for all programming languages. It is particularly important when using a new language so that you only have to debug one or two errors at a time and you know where the bugs are.
For an assignment in one of my classes we need to model disease spread and also have the turtles, whether sick or healthy, reproduce when a male and a female end up on the same patch, and it's also based on a slider with probability of reproduction. We're supposed to have the gender assigned randomly at birth so that the reproduction works properly. Any idea how to do this?
This is my code so far:
to setup
clear-all
ifelse netlogo-web? [set max-turtles 300] [set max-turtles 300]
create-healthy-cows Population-Size [ set shape "cow"
set color lime
set infected? false
set disease? false
ask n-of (random Population-Size) turtles [set gender-male? true]
set size 3
setxy random-xcor random-ycor
set age random 200
set label-color black ]
end
and also:
to check-reproduction
ask turtles [if gender-male? = false [
ask turtles [if any? turtles-here with [gender-male? = true]
[reproduce-cows] ]]]
end
to reproduce-cows
ask turtles [ if max-turtles < 300 [
ask turtles [if age >= 50 [if (random-float 100 < Reproduction-Rate)
[hatch 1
[set color blue] ]]]]]
end
Also I have gender-male? set as a turtles-own.
Have a look at one-of and see if you can come up with a solution. It's important to learn what you're doing and why, and not just ask for the answer, especially when its for a class assignment.
I've never seen or heard of NetLogo and it took me less than 5 minutes to come up with a solution and then find a second, better one.. Especially if this is an assignment you should be googling and researching instead of asking to be spoonfed!
I would like to create some turtles in a radius of another breed agent.
I have this example code:
breed [ readers reader ]
undirected-link-breed [ rris rri ]
breed [ tags tag ]
to setup
clear-all
set xy-file "locations.txt"
setup-readers
setup-tags
end
to setup-readers
create-readers num-readers [
set shape "circle"
set color white ; means idle state 'red' is active
setxy random-xcor random-ycor
]
end
to setup-tags
create-tags tag-population [
setxy random-xcor random-ycor in-radius 6 of one-of readers
]
end
The line setxy... to place the tags in a circle of distance 6 from one of the readers it does not work, but I do not know how to fix it. I have also tested move-to primitive without good result.
What I would like is to have a population of tags in a radius of each reader and if possible select the number of tags for each reader to be different.
The sprout primitive might get you what you need- instead of creating your tags and then moving them, just have the appropriate patches spawn them directly. For example, with this setup:
breed [ readers reader ]
breed [ tags tag ]
to setup
clear-all
setup-readers
setup-tags
reset-ticks
end
to setup-readers
create-readers 5 [
set shape "circle"
set color white
setxy random-xcor random-ycor
]
end
You can make a population of patches that are within the radius of readers and have however many you like sprout a tag:
to setup-tags
let radii-patches patch-set []
ask readers [
set radii-patches ( patch-set radii-patches patches in-radius 6 )
]
; Code above defines the patch-set of patches within 6 of readers
; Then, just ask 10 of those radii patches to sprout a tag
ask n-of 10 radii-patches [
sprout-tags 1
]
end
If you are doing this on a per-reader basis and you want each to have a different number of tags, you could try something like:
to setup-tags-reader
let n-tag random 5
ask readers [
ask n-of n-tag patches in-radius 6 [
sprout-tags 1
]
]
end
but then set the n-tag value some other way (for example, from another .csv file as you seem to be setting reader location).
Side note- when you post on here try to strip out any code than cannot be directly copied and pasted into Netlogo by other users (eg the 'xy-file' line, the tag-population and num-readers variables)- it just makes things super simple!
Edit
As per your comment- try this option (using the same setup as above)
to setup-tags
create-tags 10 [
move-to one-of readers
rt random-float 360
fd random-float 6
]
end
This just creates tags, moves them to a reader, has them randomly select a direction, then has them step forward a random amount from 0 to 6.
As to how to assign patches to each reader- just make a readers-own variable then have them assign patches to that variable in their setup (eg, set my-patches patches in-radius 6). You could do a similar thing with tags to define a reader-specific set of tags (eg `set my-tags tags in-radius 6). Note that in both cases you can get overlap where two readers share patches/tags- you will have to account for that.
I am new at net logo and I want to write a model based on tragedy of the commons in the case of an overfished pond. The purpose is to find an equilibrium between fishers and fishes based on an economic model with demand and supply. If there are less fishers, more fishes will be in the pond, then after a certain time (ticks) the number of fishers increases and less fishes will be in the pond. Maybe set like a number of fishes per day that can be fished. Thus, the solution is to find a convenient number of fishers as the fishes can still reproduce. I want to have a box in the interface where I can type in a number and see what happens with the number of fishes.
I have no idea how to set this up. I hope to hear from you :)
I started with this code:
breed [fishers fisher]
breed [fishes fish]
to setup
clear-all
reset-ticks
ask patches [set pcolor blue ] ;; lake/pond in form of a rectangle in color
ask patches [ if pxcor > 8 [ set pcolor green ]]
ask patches [ if pycor > 8 [ set pcolor green ]]
ask patches [ if pycor < -8 [ set pcolor green ]]
ask patches [ if pxcor < -8 [ set pcolor green ]]
ask one-of patches with [ pcolor = blue ] [ sprout 20 [set shape "fish" set color pink set size 1.5 ]] ;; creates fishes
ask one-of patches with [ pcolor = green ] [ sprout 2 [set shape "person" set color black set size 3 ] ] ;; creates fishers
end
to go
tick
;;fishes
ask turtles with [ shape = "fish" and color = pink ]
[ right random 360 forward 1
if [pcolor] of patch-ahead 1 = green [ right 180 fd 1 ]]
;; fishers
ask turtles with [ shape = "person" and color = black]
[;right random 360 forward 1
if any? patches with [pcolor = blue]
[set heading towards one-of patches with [pcolor = blue] forward 1]
if [pcolor] of patch-ahead 1 = blue [ right 180 fd 2 ]]
ask turtles with [shape = "person" and color = black]
[if any? turtles with [shape = "fish" and color = pink] in-radius 2
[ask turtles with [shape = "fish" and color = pink] in-radius 2 [die]]]
end
Firstly, I suggest you look through existing models in the Netlogo library (Wolf-sheep-predation model may help). You roughly have the right idea in your current code, but you should look at other models to improve. You've already set your different breeds of turtles, but you should also set up their respective shapes under 'setup'. This would help you a great deal later - instead of calling for
ask turtles with [ shape = "fish"...]
you can simply
ask fishes [do sth...]
For that 'box at the interface', you can have a slider at the interface determining the number of fishers you want your run to start with. With another slider, you can set the fishing pressure in your simulated run (i.e. how many fish each fisher will catch) and I suppose you can also consider how this changes when population of fish decreases.
Finally, for a model like yours, you can observe the supply and demand trend by plotting the curves of no. of fishers over time and no. of fishes over time. Again, look at the wolf-sheep-predation model to have an idea of how to do this.
I can't give you more than this I'm afraid since I'm no pro myself but hope this helps a little. Hope someone else would be able to give you a clearer idea.
I want to create turtles, which they place in a desired area with random coordinate:
they should place in the white area and in middle of it in a line. in other words, in the top regtangle, their xcor should be random and their ycor is 10. in the right regtangle, their ycor should be random and their xcor is 10 and so on.
When you create turtles, you can give them instructions such as their location. For example:
create-turtles 1 [ set ycor 10 ]
Alternatively, you can sprout the turtles from the relevant patches and their location will already be set. For example:
ask n-of 5 patches with [pcolor > 1] [ sprout 1 ]
to place-on-color [#color]
let _patches (patches with [pcolor = #color])
ask turtles [
move-to one-of (_patches with [not any? turtles-here])
]
end
Add error checking if you may have too many turtles. (Or remove the unique occupancy constraint if you don't want it.)