I have this code from book Agent-based and individual based-modeling by Railsback chapter 16 but it doesn't work and I don't know why. I am new in NetLogo, the software shows "Expected keyword" in line 22. (create-packs)
breed [dogs dog]
breed [packs pack]
breed [disperser-groups disperser-group]
dogs-own
[
age
sex
status
my-pack
my-disperser-group
]
packs-own [pack-members]
disperser-groups-own
[
sex
group-members
]
create-packs initial-num-packs
[
; set a location and shape just for display
setxy random-xcor random-ycor
set shape "box"
; create the pack’s dogs
let num-dogs random-poisson initial-mean-pack-size
hatch-dogs num-dogs
[
; first, set display variables
set heading random 360
fd 1
; now assign dog state variables
ifelse random-bernoulli 0.5
[set sex "male"]
[set sex "female"]
set age random 7
set-my-status ; a dog procedure that sets
; social status from age
set my-pack myself ; set dog’s pack to the one
; creating it
] ; end of hatch-dogs
; Initialize the pack’s agentset that contains its dogs
set pack-members dogs with [my-pack = myself]
; show count pack-members ; Test output – off for now
; now select the alpha dogs
update-pack-alphas ; a pack procedure to give the
; pack 2 alphas
] ; end of create-packs
to go
tick
if ticks > years-to-simulate [stop]
; First, age and status updates
ask dogs
[
set age age + 1
set-my-status
]
ask packs [update-pack-alphas]
; Second, reproduction
ask packs [reproduce]
; Third, dispersal
ask packs [disperse]
; Fourth, mortality
ask dogs [do-mortality]
; Fifth, mortality of collectives
ask packs [do-pack-mortality]
ask disperser-groups [if count group-members = 0 [die]]
; Sixth, pack formation
ask disperser-groups [do-pack-formation]
; Finally, produce output
update-output
end
to disperse ; a pack procedure
; First, identify the subordinates and stop if none
let my-subordinates pack-members with
[status = "subordinate"]
if not any? my-subordinates [stop]
; Now check females
if count my-subordinates with [sex = "female"] = 1
[
if random-bernoulli 0.5
[
create-disperser-group-from
my-subordinates with [sex = "female"]
]
]
if count my-subordinates with [sex = "female"] > 1
[
create-disperser-group-from
my-subordinates with [sex = "female"]
]
; And check males
if count my-subordinates with [sex = "male"] = 1
[
if random-bernoulli 0.5
[
create-disperser-group-from
my-subordinates with [sex = "male"]
]
]
if count my-subordinates with [sex = "male"] > 1
[
create-disperser-group-from
my-subordinates with [sex = "male"]
]
end ; to disperse
to create-disperser-group-from [some-dogs]
; a pack procedure
; "some-dogs" is an agentset of the dispersers
; First, create a disperser group and put the dogs in it
hatch-disperser-groups 1
[
; Set disperser group variables
set group-members some-dogs
set sex [sex] of one-of some-dogs
; Display the group
set shape "car"
set heading random 360
fd 2
; Now the disperser group sets the variables of the
; dispersing dogs
ask some-dogs
[
set my-disperser-group myself
set status "disperser"
set color green
; and display them in a line from the disperser group
move-to my-disperser-group
set heading [heading] of my-disperser-group
fd 1 + random-float 2
] ; end of ask some-dogs
] ; end of hatch-disperser-groups
; Finally, remove the dispersers from their former pack
let dogs-former-pack [my-pack] of one-of some-dogs
ask dogs-former-pack
[set pack-members pack-members with
[status != "disperser"]]
end ; to create-disperser-group-from
Thanks
you need to start a procedure with the word to but you are not allowed to call a procedure create-packs because that's actually a NetLogo command. I don't have the book to hand, but I suspect this is the setup procedure. Add the procedure name in the previous line, probably this:
to setup
create-packs initial-num-packs
you also need to end each procedure with the word end, which is also missing. Should look like this further down:
end
to go
In the future, do the syntax checking (green tick) at the end of every block of code rather than typing the whole page. That way you have some idea of where the error is and you can compare what you have typed with what's in the book.
Related
I am writing a NetLogo model of a housing market and its political ramifications. There are two breeds in the model: households and houses. An early step in my development with which I am having difficulty is having households match to houses via one of two types of links, own or rent, defined by nested conditional statements. This has resulted in two difficulties I haven't been able to overcome as of yet.
Within the command setup-market command, I'm trying to define a set of possible houses to purchase for each household which, if they meet a set of conditions, the household then buys (and creates a link). If it cannot afford to buy, then it will try to rent. If it cannot afford to rent the household will die.
My code continually results in the following error:
IFELSE expected input to be a TRUE/FALSE but got the turtle (house XXX) instead.
There is a further issue I'm having as well later in the code (in the two lines commented out with ";") where I attempt to set the variables owner-occupied and renter to 1 based on the presence of the appropriate link (they should remain 0 and the household should die if it remains unlinked).
The full code is below. The line with ";; This is the line giving me trouble" denotes where the error seems to be occurring.
UPDATE:
Code has been updated with JenB's solution. Resulting error is now:
CREATE-LINK-WITH expected input to be a turtle but got NOBODY instead. which occurs at the line: create-link-with one-of potentialHomes [ set color red
undirected-link-breed [own-links own-link]
undirected-link-breed [rent-links rent-link]
breed [city-centers city-center]
breed [households household]
households-own
[
age
money
income
monthly-income
consumption
monthly-consumption
hh-size race
preference
net-income
net-monthly-income
myHouse
]
breed [houses house]
houses-own
[
cost
down-payment
mortgage-payment
rent
rent-premium
rooms
onMarket
owner-occupied
rental
onMarket?
]
patches-own [
seed? ;;district seed
district ;;district number
full? ;;is the district at capacity?
quadrant
]
to setup
clear-all
reset-ticks
setup-patches
set-default-shape households "person"
create-households num-households [ setxy random-xcor random-ycor ]
set-default-shape houses "house"
create-houses num-houses [ setxy random-xcor random-ycor ]
setup-households
setup-houses
setup-market
generate-cities
end
to generate-cities
let center-x random-xcor / 1.5 ;;keep cities away from edges
let center-y random-ycor / 1.5
end
to setup-patches
ask patches with [pxcor > 0 and pycor > 0] [set quadrant 1 set pcolor 19 ]
ask patches with [pxcor > 0 and pycor < 0] [set quadrant 2 set pcolor 49 ]
ask patches with [pxcor < 0 and pycor < 0] [set quadrant 3 set pcolor 139 ]
ask patches with [pxcor < 0 and pycor > 0] [set quadrant 4 set pcolor 89 ]
end
to setup-households
ask households
[ set age random-poisson 38
set money random-exponential 30600
set income random-exponential 64324
set monthly-income income / 12
set consumption .5 * income
set monthly-consumption consumption / 12
set hh-size random 6 + 1
set net-income income - consumption
set net-monthly-income monthly-income - monthly-consumption
]
end
to setup-houses
ask houses
[ set cost random-normal 300000 50000
set down-payment cost * down-payment-rate
set mortgage-payment (cost - down-payment) / 360
set rooms random-exponential 3
set onMarket 1
set rent mortgage-payment + mortgage-payment * .25
set owner-occupied 0
set rental 0
]
end
to setup-market
ask houses
[ set onMarket? TRUE ]
ask households
[ ifelse any? houses with [ [money] of myself > down-payment and [net-monthly-income] of myself > mortgage-payment ]
[ let potentialHomes houses with [[money] of myself > cost and onMarket? ]
create-link-with one-of potentialHomes [
set color red
]
]
[
ifelse any? houses with [ [net-monthly-income] of myself > rent]
[ let potentialRentals houses with [ [net-monthly-income] of myself > rent and onMarket? ]
create-link-with one-of potentialRentals [ set color blue ]
]
[ die ]
]
]
ask houses
[ if any? link-neighbors [set onMarket FALSE ]
;if any? link-neighbors and color red [ set owner-occupied 1 ]
;if any? link-neighbors and color blue [ set rental 1 ]
]
end
to go
move-households
tick
end
to move-households
ask households [
move-to myHouse
]
end
You don't need to "suspect" where the problem is, NetLogo points to the problem line. Running your code, the problem is actually ifelse one-of houses with [ [net-monthly-income] of myself > rent]. Looking at that line, you pull out a randomly selected house from the pool with rent less than income. But you don't have a condition for the ifelse to test.
In previous constructions you have had != nobody at the end but you forgot that in this line. That will fix the error, but your code would be much less error prone if you used any? instead. You seem to be using one-of .... != nobody to test whether there are any turtles that satisfy the condition. That's what any? is for.
So instead of:
ifelse one-of houses with [ [net-monthly-income] of myself > rent] != nobody
[ let potentialRentals houses with [[money] of myself > rent and onMarket = 1 ]
create-link-with one-of potentialRentals [ set color blue ]
]
[ die ]
you can have:
ifelse any? houses with [ [net-monthly-income] of myself > rent]
[ let potentialRentals houses with [[money] of myself > rent and onMarket = 1 ]
create-link-with one-of potentialRentals [ set color blue ]
]
[ die ]
I should add that there is a potential logic problem here. Say there are houses with rent lower than income, the code goes to the first (true) actions. But there's no guarantee that there are any houses that satisfy the new conditions, which are different.
Also, NetLogo has the concept of true and false so you don't need to use 1 and 0. By convention (but not required), boolean variable names end with a question mark. So you could have set onMarket? true instead of set onMarket 1. Why would you do this? It makes logical operators cleaner and easier to read (which reduces bugs). Your line:
let potentialRentals houses with [[money] of myself > rent and onMarket = 1 ]
would look like:
let potentialRentals houses with [[money] of myself > rent and onMarket? ]
And you can do things like if not onMarket? instead of if onMarket? = false or if onMarket = 0
I am simulating a classroom. In a classroom there are about 90 seats, 20 lights, 20 fans and 4 ACs. I create num-of-students where each student has an assigned random entry-time. When each student enters after a random time and sits on a seat the corresponding (in-radius)light or fan or ac turn on and a link is established between the the student and the in-radius appliance. Each appliance (e,g light, fan and AC) has their own wattage value. After all the students sits down the total energy consumption (in KWh) will be calculated for all the fans, lights and ACs.
How can I store the on-time of each appliance e.g (time minus entry-time), where time is the total class time. So that afterwards I can sum all the on-time of each appliance(e.g fan) and multiply it with its watt value. This is the part of the code.
globals[
temp1 simulation-timer number-of-seats number-of-lights number-
of-fans number-of-acs ]
breed [lights light]
breed [fans fan]
breed [acs ac ]
breed [students student ]
to setup
...
...
place-seats-students
place-lights
place-fans
place-acs
create-students-classroom
end
to create-students-classroom
create-students number-of-students [
set entry-time random threshold + 1
let stu-no sort-on [who] students
foreach stu-no [x -> ask x [ show (word x " -> " entry-time )
] ]
ask students [
set shape "person"
set color 3
] ]
end
to go
set simulation-timer 0
output-show (word "timer = "simulation-timer )
tick
move-students
while [simulation-timer < time ] [
set simulation-timer simulation-timer + 1
output-show (word "timer = "simulation-timer )
end
to move-students
let s sort [who] of seats
let a first s
let l length s
while [ l > (number-of-seats - number-of-students )] [
set temp1 simulation-timer
tick
tick
ask students [ if ( entry-time = temp1 ) [
move-to seat a
set color red
ask students
[create-links-with lights in-radius 5
create-links-with fans in-radius 5
create-links-with acs in-radius 9 ]
show (word "number of links is" count links)
appliance-on
store-on-time
show (word temp1 "," l "," a)
set s remove a s
set a a + 1
set l length s
]
]
set simulation-timer simulation-timer + 1
output-show (word "timer = "simulation-timer )]
end
to appliance-on
ask students with [color = red ]
[ask my-links
[ask other-end [set color green] ] ]
stop
end
to store-on-time
ask students [
ask link-neighbor fan ifelse it is on [
let on-time [ time - entry-time ]
[do nothing]
ask students [
ask link-neighbor light ifelse it is on [
let on-time [ time - entry-time ]
[do nothing]
end
How can I write the store-on-time procedure, so that later I will be able sum to all the on-times for all the appliance to calculate the KWh consumed. Any help will be greatly appreciated.
If you need to store something, then you need to create a variable for it. Since they might turn on, off, on etc, I would personally have two variables for each appliance (eg lights-own and fans-own etc). For lights, they could be named light-on-time, light-on-duration and similarly for others.
The way this works in code is add
set light-on-time ticks
whenever you turn the light on. And have
set light-on-duration light-on-duration + ticks - light-on-time + 1
whenever you turn the light off. The reporter ticks is just the current state of the clock.
In my model the turtles have two sexes and there are two potential strategies "0" and "1". The females count the number of males in a set radius and choose among that pool based on their strategies.
The females have a limit to their pool of potential mates and they loop through this pool to select the males according to their strategy. This is all in the to-choose procedure.
One issue that a colleague picked up on is that the following line of code should be updated every time a female chooses another mate so that the proportion reflects the remaining potential mates and not the n-max which was set outside of the loop.
set prop_B ( count availa-males with [ strategy = 0 ] ) / n-max
To state the issue another way for clarity if the n-max is 5 and a female sets the prop_B using this value for the first mate then in the next iteration of the loop n-max should deprecate by 1 because there are only 4 remaining males.
So it should be something like: set prop_B ( count availa-males with [ strategy = 0 ] ) / (n-max - count mates-already-chosen)
Please see below for a working example of the model. Hope you can help.
turtles-own [sex availa-males mates mate-count max-mate-count strategy n-max prop_B proba_B]
breed [males male]
breed [females female]
to setup
clear-all
create-males 50
create-females 1
ask turtles [
setxy random-xcor random-ycor
ifelse random 2 = 1 [set strategy 1] [set strategy 0]
]
ask males [set color red]
ask females [set color blue]
reset-ticks
end
to go
ask males [
; fd 1
]
ask turtles [
set mates ( turtle-set )
]
ask females [choose]
tick
end
to choose
; set a cap on possible mates for females; 5, or the number
; available within the radius if less than 5
set availa-males males in-radius 5
set n-max count availa-males
set max-mate-count ifelse-value ( n-max < 5 ) [ n-max ] [ 5 ] ; 5 5
; Until a female has chosen up to her maximum number of mates:
while [ mate-count < max-mate-count ]
[; determine which available males are not already in her 'mates' agentset
set availa-males availa-males with [ not member? self [mates] of myself ]
; assess the proportion of the '0' strategy in remaining available males
set prop_B ( count availa-males with [ strategy = 0 ] ) / n-max
; example probability choice, just meant to choose '0 strategy' males
; with a frequency disproportionate to availability
set proba_B ifelse-value ( prop_B <= 0.1 ) [ 0.8 ] [ 0.2 ]
; use a random float to determine which strategy type is chosen
set mates ( turtle-set mates
ifelse-value ( random-float 1 < proba_B )
[ one-of availa-males with [ strategy = 0] ]
[ one-of availa-males with [ strategy = 1]] )
; count the current mates to break the while loop once
; the maximum number of mates is reached
set mate-count count mates
]
; have the female's males add her to their own mates agentset
ask mates [ set mates ( turtle-set mates myself ) ]
if n-max < count mates [ print "Fewer available males than mates" ]
end
Since you don't need them to be selected sequentially, then one option you should think about is the weighted equivalent of n-of from the rnd extension. The following code is a complete model that uses weighted selection, to show you how it could work. But it won't give quite the same results as your approach. Your mathematics basically forces one choice or the other based on the proportion of each. I thought that might work for you anyway, as the weighting is just a demonstration of disproportional.
extensions [rnd]
turtles-own
[ sex
mates
strategy
]
breed [males male]
breed [females female]
to setup
clear-all
create-males 50 [set color red set sex "M"]
create-females 1 [set color blue set sex "F"]
ask turtles
[ setxy random-xcor random-ycor
set strategy one-of [1 0]
set mates nobody
]
reset-ticks
end
to go
ask males
[ ; fd 1
]
ask females [choose]
tick
end
to choose
let availa-males males in-radius 5
let max-mate-count min (list 5 count availa-males)
if max-mate-count < 5 [ print "Fewer available males than mates" ]
let new-mates rnd:weighted-n-of max-mate-count availa-males [ strategy-weight strategy ]
set mates (turtle-set mates new-mates)
ask new-mates
[ set mates (turtle-set mates myself)
]
end
to-report strategy-weight [ #strategy ]
if #strategy = 1 [ report 0.2 ]
if #strategy = 0 [ report 0.8 ]
report 0
end
You will notice I also removed a bunch of turtle variables. You don't need to have a permanent variable, just create a temporary one with let. I also noticed you have sex as a turtle variable, but you are actually handling sex with different breeds, but I left it in just in case it has some other purpose.
In my model the turtles have two sexes where the males have two potential tactics. The females count the number of males in a set radius.
I want the females to weight their probability of selecting from the group of males (without replacement) depending on the relative frequency of the two male tactics.
I already have the code for the probability of selecting from the males (matingPoolProbAnad and matingPoolProbRes) but I don't know how to implement it, though the rnd extension seems the way to go, specifically rnd:weighted-n-of size agentset [ reporter ].
It's complicated by three things (1) the males can mate with more than one female but (2) only once with a given female and (3) females can only mate with a maximum of five males.
to count-mates ; ask the females to count the number of males in a 10 patch radius & then
; determine the frequency of the resident males in their patch
ask turtles with [sex = "female"]
[
if any? turtles with [sex = "male"] in-radius 10
[ set potentialMates turtles with [sex = "male"] in-radius 10
ifelse any? potentialMates with [anadromousM = 1]
[ set FA count potentialMates with [anadromousM = 1] / count potentialMates ]
[ set FA 0]
ifelse any? potentialMates with [anadromousM = 0]
[ set FR count potentialMates with [anadromousM = 0] / count potentialMates ]
[ set FR 0]
]
]
end
to mating-pool-prob ; negative frequency dependency which is based on the number of male
; resident turtles
ask turtles with [sex = "female"]
[
ifelse (FA = 1) and (FR = 0)[
set matingPoolProbAnad 1
set matingPoolProbRes 0
]
[ifelse (FA > 0) and (FR < 1)
[
set matingPoolProbRes exp(a - b * (FR - c ))/(1 + exp(a - b * (FR - c)))
set matingPoolProbAnad 1 - matingPoolProbRes
]
[
set matingPoolProbAnad 0
set matingPoolProbRes 1
]
]
]
end
This example may approach what you're getting at, but obviously would need to be adapted from this toy version. This setup sprouts 75% of males with strategy A and the rest with strategy B, and gives all turtles an empty agentset of mates to start off:
breed [ males male ]
breed [ females female ]
turtles-own [ mates ]
males-own [ strategy ]
females-own [ max-mate-count mate-count ]
to setup
ca
ask n-of 200 patches [
sprout-males 1 [
ifelse random-float 1 < 0.75 [
set strategy "A"
set color orange
] [
set strategy "B"
set color violet
]
]
]
ask n-of 50 patches with [ not any? turtles-here ] [
sprout-females 1 [
set color green
]
]
ask turtles [
set mates ( turtle-set )
]
reset-ticks
end
Use a while loop to have each female iteratively assess the strategy proportions of the males available to her, then add them to her 'mates' list. More detail in comments:
to choose-mates
ask females [
; set a cap on possible mates for females; 5, or the number
; available within the radius if less than 5
let availa-males males in-radius 10
let n-max count availa-males
set max-mate-count ifelse-value ( n-max < 5 ) [ n-max ] [ 5 ]
; Until a female has chosen up to her maximum number of mates:
while [ mate-count < max-mate-count ] [
; determine which available males are not already in her 'mates' agentset
set availa-males availa-males with [ not member? self [mates] of myself ]
; assess the proportion of B strategy in remaining available males
let prop_B ( count availa-males with [ strategy = "B" ] ) / n-max
; example probability choice, just meant to choose B males
; with a frequency disproportionate to availability
let proba_B ifelse-value ( prop_b * 2 < 0.6 ) [ prop_b * 2 ] [ 0.6 ]
; use a random float to determine which strategy type is chosen
set mates ( turtle-set mates ifelse-value ( random-float 1 < proba_B )
[ one-of availa-males with [ strategy = "B" ] ]
[ one-of availa-males with [ strategy = "A" ] ] )
; count the current mates to break the while loop once
; the maximum number of mates is reached
set mate-count count mates
]
; have the female's males add her to their own mates agentset
ask mates [
set mates ( turtle-set mates myself )
]
]
end
To check that 'B' males are being chosen disproportionately to their availability:
to check-values
let all-mates map [ i -> [strategy] of i ] [mates] of females
print word "Average proportion of 'B' mates chosen: " mean map b-proportion all-mates
print word "Actual proportion of 'B' males: " ( ( count males with [ strategy = "B" ] ) / count males )
end
to-report b-proportion [ input_list ]
let tot length input_list
let nb length filter [ i -> i = "B" ] input_list
report nb / tot
end
I'm not 100% sure that that's what you're after- maybe you can use the rnd package to clean up the loop.
Edit in response to comment
If you modify the end of the `choose-mates like so:
...
...
; have the female's males add her to their own mates agentset
ask mates [
set mates ( turtle-set mates myself )
]
if n-max < count mates [
print "Fewer available males than mates"
]
]
end
And your go looks like:
to go
choose-mates
end
You can run setup and go as many times as you like and you should never see the printout "Fewer available males than mates":
to repeat-1000
repeat 1000 [
setup
go
]
end
I ran that a few times and never had count availa-males be less than the count of mates. However, if you add in movement without allowing the females to reset their mates agentset, you do start to see it- for example, try running this a few times:
to go
choose-mates
ask turtles [ fd 1 ]
end
Now, because the turtles are moving around, you have some cases where females held on to their mates from the previous function call and then moved into a space where there were fewer availa-males. The quick and easy fix is to have females clear their mates each time. Where you do that depends on your model goals (how often do females choose mates? Do they only forget some of their previous ones? etc), but here's a very simple way:
to go
ask turtles [ set mates ( turtle-set ) ]
choose-mates
ask turtles [ fd 1 ]
end
Now you can run that as many times as you like and shouldn't see the "Fewer available males than mates" printout.
I am growing animal territories. Animal territories may cleave parts of other animal territories during the process of expand. So instead of being one contiguous territory, the territory may include more than one cluster (i.e., unattached clusters). This is what happens in the model below. I'd like to have the territory recognize this and release whichever cluster of cells (or a single unattached cell) is smallest so that the territory remains one contiguous cluster. I'm not sure where to start with this. Any help would be great.
breed [animals animal]
breed [homeranges homerange]
animals-own
[
Name
orig
territory
food
status
]
patches-own
[
owner
prey
]
to setup
clear-all
random-seed 2234
ask patches
[
set owner nobody
set prey 2
set pcolor scale-color (black) prey 1 4
]
let $colors [brown orange violet sky lime]
let $Name ["t6" "t7" "t8" "t9" "t10"]
let $status [0 0 0 0 5]
ask n-of 5 patches
[
sprout-animals 1
[
set shape "circle"
set orig patch-here
set territory patch-set orig
set status item who $status
set size 0.3 + 0.1 * status
set color item who $colors
set pcolor color
set Name item who $Name
set owner self
]
]
reset-ticks
end
to go
if all? animals [food >= 350] [ stop ]
if ticks = 70 [ stop ]
expand
tick
end
to expand ; animals procedure
repeat 10
[
ask animals
[
let vacant no-patches
let subord no-patches
let target nobody
let new-patches no-patches
let status-of-calling-tiger status ;
let calling-tiger self ;
; If territory not yet good enough:
if food < 500
[
ask territory
[
; Add unoccupied neighbor patches as potential targets:
set vacant (patch-set vacant neighbors with [owner = nobody])
; Add occupied neighbor patches as potential targets if their tiger has a lower status than me:
set subord (patch-set subord neighbors with [owner != nobody and [status] of owner < status-of-calling-tiger])
]
ask subord [ set pcolor red ]
; Set of all potential targets:
set new-patches (patch-set new-patches vacant subord)
; Choose as target the one potential target with highest prey:
if any? new-patches
[
ask new-patches
[ifelse any? vacant
[ifelse any? subord
[ifelse [prey] of max-one-of vacant [prey] = [prey] of max-one-of subord [prey]
[set target max-one-of vacant [prey]]
[set target max-one-of new-patches [prey]]
]
[set target max-one-of vacant [prey]]
]
[set target max-one-of subord [prey]]
]
move-to target
if-else member? target subord
[ set shape "triangle" ] ; so you can see that the target patch was from "subord"
[ set shape "circle" ] ; or from "vacant"
]
;ifelse any? target with [owner != nobody]
if target != nobody
[
; Add target patch to territory of the current animal:
set territory (patch-set territory target) ; this is the territory of the calling tiger
let old-owner [owner] of target; this needs to be memorized
; Tell target patch that is has new owner:
ask target [ set owner calling-tiger ]
; Tell the original owner of the target patch to remove the target patch from its territory:
if old-owner != nobody ;
[
ask old-owner
[
set territory territory with [ owner != calling-tiger ]
]
]
]
set food sum [prey] of territory
]
]
]
ask animals
[
ask territory
[
set pcolor [color] of myself
set plabel (word [status] of owner [status] of myself)
]
if food < 10 [die]
]
end
Patch Clusters Example, in the Code Examples section of NetLogo's Models Library, has code for identifying a contiguous cluster of patches. The core code is as follows:
patches-own [cluster]
to setup
...
ask patches [ set cluster nobody ]
...
end
to grow-cluster ;; patch procedure
ask neighbors4 with [(cluster = nobody) and
(pcolor = [pcolor] of myself)]
[ set cluster [cluster] of myself
grow-cluster ]
end
But see the rest of the example as well.
In your use case, instead of placing the "seeds" randomly for growing the clusters, you'll start growing the clusters in the patches where the animals are standing.