How do I assign a gender randomly to turtle breeds in NetLogo? - netlogo

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!

Related

How to divide world in regions of specific size?

I am having troubles building my model: I am trying to build an agricultural area, where a specific number of farmers have lands of different sizes (also specific, not random). In the farmers' proprieties, there are fields (yellow patches) and forest (green patches).
Here's a bit of code:
breed [Smallfarmers Smallfarmer] Smallfarmers-own [property]
breed [Mediumfarmers Mediumfarmer]
Mediumfarmers-own [property]
to setup
ca
loop [
repeat 50[
create-Smallfarmers 1 [
set property [patches in-radius-nowrap 1.5] of one-of patches with [pcolor = black]
if all? (patch-set [neighbors] of property) [pcolor = black] [
ask n-of 2 property [set pcolor green]
ask property with [pcolor != green] [set pcolor yellow]]]]
repeat 10[
create-Mediumfarmers 1 [
set property [patches in-radius-nowrap 2.9] of one-of patches with [pcolor = black]
if all? (patch-set [neighbors] of property) [pcolor = black] [
ask n-of 6 property [set pcolor green]
ask property with [pcolor != green] [set pcolor yellow]]]]
stop]
end
With this code I have these problems:
not all the farmers are created.
the properties are floating in the black space, far apart.
How can I improve (or completely revolutionize) my code?
There are several distinct issues with this. The first are general NetLogo bits:
Using in-radius-nowrap suggests to me that you have the world wrapping and don't really want it to wrap since it is land and it doesn't make sense to wrap. You can turn off wrapping with the settings button (top right) on the interface, where you also set the number of patches in the world.
If you want to create (say) 10 farmers, you don't need to do repeat 10 [create-farmers 1 ..., you just create 10 at once. All the code in the [ ] that sets up the property will happen for each farmer because it is part of the create block.
neighbors is already a patchset, but I suspect you want to include the central patch as well
Your specific problem about too few properties too far apart - In fact, all the farmers and their properties are being created but their properties are not being coloured. Your code creates a farmer and gives them property, but only colours it if the property does not overlap.
So to fix this, you need to create the farm only where there is space. It is probably easier to create the larger farms first, and then the smaller farms can fill in the gaps. Looking at your code though, all the farms are the same size (3x3) and the difference is how many fields are green or yellow. Here is some code that creates farms (notice also that it puts the farmer on the farm).
breed [farmers farmer]
farmers-own
[ property
]
to setup
clear-all
create-farmers 10
[ let potential-farms patches with [all? (patch-set self neighbors) [pcolor = black]]
ifelse any? potential-farms
[ move-to one-of potential-farms
set property (patch-set patch-here neighbors)
ask n-of 2 property [set pcolor green]
ask property with [pcolor != green] [set pcolor yellow]
]
[ print "No space available" ]
]
end

Network modelling using Netlogo

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.

Set Radius to find a partner turtle

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

Netlogo - how to count turtles number around a specific turtle

I need to "do-something-special" if around yellow turtle there is at least 3 blue turtles . Is the code bellow correct?
I tried
ask turtles with [color = yellow]
[
if count turtles in-radius 1 with [color = blue] >= 3
[do-something-special]
]
do-something-special should remove (disappear) 3 of blue turtles and current yellow one
Did I do the location of relevant turtles correctly and how do I kill them after I find them?
Hannah's answer is good but the linked example won't fully fix your problem. Since you will be using the set of close agents twice (once to count and once to potentially remove some), you should also create an agentset for efficiency reasons (you don't want to create it twice). Here is a full solution.
ask turtles with [color = yellow]
[ let near-blue turtles in-radius 1 with [color = blue]
if count near-blue >= 3
[ ask n-of 3 near-blue [die]
die
]
]
Also, if you don't care about the exactness of the radius, an alternative to turtles in-radius 1 would be turtles-on (patch-set neighbors patch-here), which is all the turtles on the neighbouring and same patches to wherever your asker turtle is sitting.
At the moment your code counts the amount of turtles that are blue in the radius of one patch around the yellow turtle. If the amount of blue turtles is bigger/equal 3 the yellow turtles die if you use the "die" command instead of "do-something-special". So it looks as follows.
ask turtles with [color = yellow]
[
if count turtles in-radius 1 with [color = blue] >= 3
[die]
]
Maybe you can merge the code with the following example and then kill the neighbors.

set a demand and supply curve for the model tragedy of the commons in the case of an overfished pond

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.