I've got a doozy of a Netlogo question. If I have two different breeds of turtles, can the sum of a specified number of one breed's variables BE THE VARIABLE of the other breed?
Here is my train of thought. I’d like to model water usage of multiple households, but that water usage of a household needs to be dependent on a) the fixed values of the house (like water used by a faucet) * b) frequency of use of faucet by a person. With each household containing either 1 or more person (people) and that frequency of use can vary person to person.
The idea of using two turtle breeds would allow me to see how the decisions made by one breed affects the other.
Here is my pseudo code to help illustrate what I was thinking (not intended to be a working code)
globals []
breed [People person]
breed [Community household]
People-own [frequency]
Community-own [waterusefacuet HouseholdWaterUse]
;; =================================================================================================================
;; =================================================================================================================
to setup
clear-all
HouseholdCreation
PersonCreation
reset-ticks
end
to go
ask Community [WaterConsumption]
tick
end
;; =================================================================================================================
;; =================================================================================================================
to HouseholdCreation
ask patches [ sprout-Community n of 1 [
set size 1.0 set shape "square" set color blue
set waterusefacuet (1)
] ]
end
to PersonCreation
ask Community [ hatch-People 1 [
set size 0.5 set shape "circle" set color red
set frequency (1 + random 4)
]]
end
to WaterConsumption
Set HouseholdWaterUse (waterusefacuet * (frequency * # of people) )
end
Why not simply make each patch a household, have each patch have one or more turtles (persons), and then calculate household factors as patch factors? To define communities one could place patches into zones (e.g., if pxcor >= 5 and pxcor <=8 and pycor >=3 and pycor <= 6 set zone 1) <== not meant to be code, just the idea.
You could set patch size to make each patch small and specify a large zone of patches.
can the sum of a specified number of one breed's variables BE THE VARIABLE of the other breed?
Absolutely.
snipsnip for clarification : In my code here, I do not let the water use of people who live in a household BE the water use variable of that household. And generally I would recommend against a solution that lets the state of one (or more) agents be the state of another variable - unless there is a very good reason for it. Having states depend on each other is dangerous because you always have to make sure that you sync the values between agents. More importantly, it's often unnecessary. In my solution here, each person belongs to a household, and when that households calculates its total water use, it asks all its inhabitants to send them their use on that day, and then returns the sum of all those numbers. I hope that makes sense. If not, please do ask.
*< /snipsnip>
You need to use the of keyword though. of allows you direct access to variables from the context/perspective of one or more individual agent. So, let's say we have households and people, and people (because we all have different water use habits) have some frequency of water tap uses. In fact, we could have people draw the amount of water they use every day from a a normal distribution that is unique to them. Let's do that:
breed [people person]
breed [households household]
people-own [
mean-use-per-day ;; mean use per day
sd-use-per-day ;; standard dev per day
my-household ;; the household to which a person belongs
]
to setup
create-households 10 [
hatch-people random 4 + 1 [ ;; between 1 and 4 people in a household
set mean-use-per-day random 5 + 5 ;; mean 5-9
set sd-use-per-day random-float 3 ;; sd 0.00-2.99
set my-household myself ;; we set the person's household to the household that hatched them
]
]
to-report household-water-use ;; household reporter
report sum [random-normal mean-use-per-day sd-use-per-day] of people with [my-household = myself] ;; this creates a list of water uses based on the random use of each person in the household.
end
in order to run this code, you can simply call
show [household-water-use] of households
from the command center. This will give you a list of the water use of each household. Or if you want to just see the water use of one household on one random day, you can try
show [household-water-use] of one-of households
Related
I am working on a model which is supposed to act like a human tissue. It is composed of only patches which represent the human cells. The cells replicate over time, and I want to introduce unique IDs to each of the individual patches (cells). These IDs should also carry over to the daughter cells after the replication. I cannot seem to find a good starting point for this and not sure how to approach it.
This is the code I tried but it is not working to even at least give each patch a unique ID. Track clones is supposed to give each of the patches an ID and I will later introduce more to the code to track individual patches and their division over time.
to track-clones
; let patch-list patches
; let patch-count count patches
; foreach patch-list [
; set id ?1
; ]
end
This will have each patch take unique and sequential IDs:
to assign-ids
ask patches [
set id (max [id] of patches + 1)
]
end
That said, it is not clear to me what you mean, in model's terms, when you say
These IDs should also carry over to the daughter cells after the replication.
given that we don't know how such replication is supposed to take place - but it seems this is a separate issue to address.
PS: the syntax using ? for anonymous procedures is no longer accepted, make sure to check the latest NetLogo Dictionary.
You can quickly assign an initial ID based on the patch coordinates
Ask patches [ set patch-id (pxcor - min-pxcor ) + (pycor - min-pxcor) * world-width
]
Alternately, you can use the patch itself as the patch ID:
Ask patches [ set patch-id self ]
This might make other operations relating to the progenitor patch simpler.
Picture of my behaviourspace menu
I'm working on an agent based model where a variable (agentvariable1) owned by all agents changes every tick. I want to report a time series for the values of this variable for every agent using Behaviourspace.
However, when I measure runs using the following reporter
[agentvariable1] of turtles
the values that are reported for agentvariable1 are randomly shuffled, because "turtles" calls all turtles in a random order, which is different every tick. Because of this the data that is exported is not usable to create a time-series.
Is it posstible to create a reporter in Behaviourspace that reports the values of the agentvariable1 in a sequence that remains the same every tick?
Using sort on an agentset creates a list of those agents sorting them by some criteria. In the case of turtles, they are sorted by their who which means that their relative order will always be the same.
However you cannot directly do [agentvariable1] of sort turtles, because of expects an agent/agentset but you are giving it a list.
What you can do is creating a global variable as a list: at each tick the list is emptied, and later all turtles (sorted as per sort) will append their value to the list.
That list is what you will report in your Behavior Space.
globals [
all-values
]
turtles-own [
my-value
]
to setup
clear-all
reset-ticks
create-turtles 5
end
to go
set all-values (list)
ask turtles [
set my-value random 10
]
foreach sort turtles [
t ->
ask t [
set all-values lput my-value all-values
]
]
show all-values
tick
end
As an alternative to Matteo's answer (which is perfectly suitable and directly addresses your intention, I just present another option depending on preference) you could also pair the variable of interest with some turtle identifier and report that as a list of lists. This adds a bit of flexibility in cases where the number of turtles increases or decreases. In this example, I use who and xcor for simplicity, but you may want to create your own unique turtle identifier for more explicit tracking. With this toy model:
to setup
ca
crt 5
reset-ticks
end
to go
ask turtles [
rt random 30 - 15
fd 1
]
tick
end
to-report report-who-x
report list who xcor
end
At any point, you can call the list with [report-who-x] of turtles to get a list of lists. With a behaviorspace setup such as:
you get an output that would look something like:
I want to write in Netlogo that a certain percentage of the agent's population has this attribute. How do I do that in NetLogo?
So far, in a toy model, I do it manually. i.e: ask n-of 740 households [set composition 1] when in fact I want to say: ask 8% of the households to set composition 1.
There are two ways. I will call them ex-ante and ex-post.
Ex-ante
A frequent approach is to let each agent have a certain chance (expressed as the percentage value) of doing something. In this case you will use the random-float command in combination with your percentage value, which is the standard way to make things happen in NetLogo according to a certain probability (see here, or also see just random if you're working with integers). It can be used directly within the create-turtles block of commands:
globals [
the-percentage
]
turtles-own [
my-attribute
]
to setup
clear-all
set the-percentage 0.083 ; In this example we set the percentage to be 8.3%.
create-turtles 500 [
if (random-float 1 < the-percentage) [
set attribute 1
]
]
end
This means that you will not always have the exact number of turtles having that attribute. If you check count turtles with [attribute = 1] on multiple iterations, you will see that the number varies. This approach is good if you want to reproduce the probability of something happening (over a population of agents or over time), which is the case for many uses of NetLogo models.
Ex-post
The ex-post approach follows the logic that you more or less expressed: first you create a number of turtles, later you assign to them the attribute. In this case, you simply need to treat the percentage as in any other mathematical expression: multiply it by the total number of turtles to get the relevant turtles:
globals [
the-percentage
]
turtles-own [
my-attribute
]
to setup
clear-all
set the-percentage 0.083
create-turtles 500
ask n-of (count turtles * the-percentage) turtles [
set attribute 1
]
end
With this approach, you will always have the exact same number of turtles with that attribute. In fact, if you run count turtles with [attribute = 1] on multiple iterations you'll see that the result is always 41 (500 * 0.083 = 41.5, in fact if the number passed to n-of is fractional, it will be rounded down).
I would like to apply some process stochastically, but the order matters, or rather it should be done at random, how can I select a set of the same turtles to "treat" but to do it such that each tick, the order is random?
ask turtles [
;; apply a process to turtles, but not all turtles will get something as the pool of energy may have run out by the time they are selected.
]
Elements of agentsets (such as turtles) are always returned in a random order. Each time you use ask with an agentset, it will ask them in a new, random order. From the docs on agentsets:
An agentset is not in any particular order. In fact, it’s always in a random order. And every time you use it, the agentset is in a different random order. This helps you keep your model from treating any particular turtles, patches or links differently from any others (unless you want them to be). Since the order is random every time, no one agent always gets to go first.
And here is a quick example to demonstrate. If you run it in the Command Center you'll see the who numbers will be different each time you ask them to be shown.
to test
clear-all
create-turtles 10
show "Asking once..."
ask turtles [ show who ]
show "Asking a second time..."
ask turtles [ show who ]
end
And here is an example showing an energy pool that will be randomly used until it is gone. Note the turtles that will get to use it are whichever happen to come first out of the agentset for ask:
to test-pool
clear-all
let energy-pool 1000
create-turtles 100
ask turtles [
; can only act if some energy is left...
ifelse energy-pool > 0 [
let energy-use (min (list random 100 energy-pool))
set energy-pool (energy-pool - energy-use)
show (word "I used up " energy-use " energy points! " who " Only " energy-pool " points left")
] [
show (word "No energy left for me! " who)
]
]
end
In NetLogo: suppose the model has
a turtle (0) of breed A with undirected links with 3 turtles (1, 2 and 3) of breed B;
the turtle 0 has an attribute named "number-of-links" that equals 3.
Now, let one of the 3 neighbors of 0 dies..
How can I program turtle 0 to change its number-of-links automatically to 2?
If all you want is a way of keeping track of the number links, use count my-links instead of a custom variable.
In general, the least bug prone way of having a value update when the number of links changes is to compute that value when you need it. For number of links, this is simply count my-links. For more complicated things, wrap them in a reporter:
to-report energy-of-neighbors
report sum [ energy ] of link-neighbors
end
If this doesn't work for whatever reason (agents need to react to a link disappearing or you're seeing a serious, measurable performance hit from calculating on the fly), you'll have to make the updates yourself when the number of links change. The best way to do this is to encapsulate the behavior in a command:
to update-on-link-change [ link-being-removed ] ;; turtle procedure
; update stuff
end
and then encapsulate the things that can cause the number of links to change (such as turtle death) in commands as well:
to linked-agent-death ;; turtle procedure
ask links [
ask other-end [ update-on-link-change myself ]
]
die
end