I'm working with Patch Cluster Example from Model Library and I wish to identify the cluster with the highest number of patches = the most extended one and then turn this cluster red.
I know that I can simply
count patches with [pvalue = X] ; X - whatever plabel of patches in connected cluster
to know what is the extent of specific cluster with [plabel = 1], cluster with [plabel = 2], cluster with [plabel = 3]... To color it, it is simply:
ask patches with [plabel = X] [
set pcolor red ]
However, can I automatically identify the most extended cluster and get the count of connected patches?
Thank you for all suggestions,
*
*
*
Which cluster is the most extended one?
You can easily adapt the find-all-components procedure from the Giant Component example in the NetLogo Models Library. For convenience, you will need to add global-variables
component-size, giant-component-size, and giant-start-node,
along with a patch attribute explored?. A quick adaptation
(warning: untested!) would be something like:
globals [component-size giant-component-size giant-start-node]
patches-own [explored?]
;; find connected components and their sizes
to find-all-components
set giant-component-size 0
set giant-start-node nobody
ask patches [ set explored? false ]
;; keep exploring till all turtles get explored
loop [
;; pick a node that has not yet been explored
let start one-of patches with [ not explored? ]
if start = nobody [ stop ]
;; reset the number of patches found to 0
set component-size 0
;; at this stage, we recolor everything to light gray
ask start [explore]
;; the explore procedure updates the component-size variable.
;; so check, have we found a new giant component?
if component-size > giant-component-size [
set giant-component-size component-size
set giant-start-node start
]
]
end
;; Finds all patches reachable from this node
to explore ;; node procedure
if explored? [ stop ]
set explored? true
set component-size component-size + 1
ask neighbors4 with [pcolor = [pcolor] of myself] [
explore
]
end
Related
I have N groups of turtles which own the variable group-id (1 to N, N is defined at setup, each group has 25 turtles).
At the beginning each group of turtles spawns on a random patch with variable patch-group-id that matches the turtle group-id, like so:
let i 0
while [ i < n_groups ] [
let x random 100
let y random 100
ask patch x y [ set patch-group-id i set pcolor gray ]
create-turtles 25 [
set group-id i
setxy x y
]
set i i + 1
]
The turtles move around but at a later step in the process I would like them to move back to their ‘home’ patch. Other turtles may also change their group-id and therefore their home patch and I would like them to move there too.
Is there any way to do a comparison along the lines of…
Ask turtles [
Let target one-of patches with [patch-group-id = group-id]
]
And then ask the turtle to move-to or jump to the target?
NetLogo doesn’t like this (‘Min-one-of expected this input to be a number block, but got a true/false block instead’) and I think there are probably other issues too.
patch-group-id is a variable owned by patches and group-id is owned by turtles. So you need to tell NetLogo which group-id the patches are trying to match to. Try this:
ask turtles
[ let target one-of patches with [patch-group-id = [group-id] of myself]
]
Another way to do this is to drop the idea of group-id and simply have each turtle remember its home patch. Conceptually, this implements the idea that a group is entirely defined by its home patch. So your setup would look something like:
turtles-own
[ my-home
]
to setup
clear-all
ask n-of n-groups patches
[ sprout turtles 25
[ set my-home patch-here
]
set pcolor gray
]
end
Then you never need to construct the target, you simply get then to go to their variable my-home.
If you went down this path, you would also need to change the code that uses group-id. For example, you said that sometimes the turtles change their group-id, instead of set group-id [group-id] of ... you would have set my-home [my-home] of ...
I am trying to create a network that moves through the environment as a "static" unit, i.e. nothing in the simulation changes except the position and orientation of the whole, the position and orientation of the individual turtles relative to one another are fixed by their links. Turtles are connected via undirected links, which are tied and set to tie-mode "fixed".
The problem is that in certain situations the links fail to remain fixed and link-lengths begin to change. Initially I noticed that, where the average network degree is relatively low or the network is a complete graph, the tie primitive works. However, when links were created to produce a graph that is moderately connected the link-lengths between the turtles begins to change. Upon further experimentation I can create a network with the same number of links and turtles but with different configurations i.e. the network structure is different, that sometimes maintain the positions and link-lengths but in other situations fail to do so.
How do I get the network to move as a unit no matter how connected the network is or what the configuration of the network is? See example code below, I have added code at the end where you can run multiple configurations of a network with 6 turtles and 6 links to see the issue for yourself, try running at least a half dozen iterations. Thanks!
this produces a network that moves as a unit
to setup
create-turtles 10
ask turtles [fd 2]
ask turtles [create-links-with other turtles [tie] ]
ask links [set tie-mode "fixed"]
reset-ticks
create-turtles 10
ask turtles [fd 2]
ask turtles [create-links-with other turtles [tie] ]
ask links [set tie-mode "fixed"]
reset-ticks
end
to go
ask turtles [lt 1 fd 1]
end
This produces a network whose links are still tied and set to tie-mode "fixed", but change their link-lengths. The more links that are asked to die, the more the link-lengths change.
to setup
clear-all
create-turtles 10
ask turtles [fd 2]
ask turtles [create-links-with other turtles [tie] ]
ask links [set tie-mode "fixed"]
ask one-of links [die]
reset-ticks
end
to go
ask turtles [lt 1 fd 1]
end
Here is additional code showing a specific instance of link-length change. Please input the seed 659269695 when prompted by the button "use-seed-from-user". Apologies if the code is clunky, first time using random-seed. "Print-lengths" button is to confirm that lengths change.
;USE seed: 659269695
to use-new-seed
let my-seed new-seed ;; generate a new seed
output-print word "Generated seed: " my-seed ;; print it out
random-seed my-seed ;; use the new seed
reset-ticks
end
;; Use a seed entered by the user
to use-seed-from-user
loop [
let my-seed user-input "Enter a random seed (an integer):"
carefully [ set my-seed read-from-string my-seed ] [ ]
ifelse is-number? my-seed and round my-seed = my-seed [
random-seed my-seed ;; use the new seed
output-print word "User-entered seed: " my-seed ;; print it out
reset-ticks
stop
] [
user-message "Please enter an integer."
]
]
end
to setup
clear-all
create-turtles 6
ask turtles [
fd 5
set shape "circle"
set size 1
set color yellow
if count links < 7 [ask one-of turtles [create-link-with one-of other turtles
[tie]]]]
reset-ticks
end
to go
ask turtles [lt 1 fd 1]
end
to print-lengths
print sort-by < [precision link-length 2] of links
end
I slightly revised your code so that the go procedure includes breaking a link. I also got rid of the explicit setting of tie-mode since that is done by setting the link to tie and added a tick so I could plot. So the code looks like this:
to setup
clear-all
create-turtles 10 [fd 2]
ask turtles [create-links-with other turtles [tie] ]
reset-ticks
end
to go
ask one-of links [die]
ask turtles [lt 1 fd 1]
tick
end
As far as I can see, the turtles move as a unit until it fragments with the loss of links.
I added a monitor for mean [link-length] of links, which is what I think you are asking about and also a plot of the same calculation. Yes, it is true that the average link length changes, but remember that the links are not all the same length. If a longer one dies, then the average length will reduce, and if a shorter one dies then the average will increase. The plot wanders a little, but it is basically flat until fragmentation.
In a land use model, I want to count the size of green and red clusters as shown in this image:
The code used is very similar to that found in "Patch Clusters example" from Models Library, with the only difference is that it only counts red and green patches. But when I run it, Netlogo states "stack overflow (recursion too deep) error while observer running ASK called by procedure FIND-CLUSTERS". Here is the find-clusters procedure:
to find-clusters
loop [
;; pick a random patch that isn't in a cluster yet
let seed one-of patches with [cluster = nobody and pcolor = 64 or
pcolor = 14]
;; if we can't find one, then we're done!
if seed = nobody
[ show-clusters
stop ]
;; otherwise, make the patch the "leader" of a new cluster
;; by assigning itself to its own cluster, then call
;; grow-cluster to find the rest of the cluster
ask seed
[ set cluster self
grow-cluster ]
]
display
end
and the grow-cluster procedure:
to grow-cluster ;; patch procedure
ask neighbors4 with [(cluster = nobody) and
(pcolor = [pcolor] of myself)]
[ set cluster [cluster] of myself
grow-cluster ]
end
What does the message mean and how can I fix it? Thanks.
double-check your first if statement.
let seed one-of patches with [cluster = nobody and pcolor = 64 or
pcolor = 14]
You will always find a patch that is "false and false or true" and will never exit the loop. Think where to put your parenthesis for order of operations.
We try to show a simple infection via Netlogo. For our purpose we need to start the infection with the same turtle for several times.
But right now with every setup another turtle begins with the infection. We already tried to work with the Node ID, but unfortunately the ID of the different turtles changes with every setup, too. We are out of ideas but
maybe there is a way to sove this problem I am happy for any answers :)
This is our Code so far:
extensions [nw]
globals
[
num-informed
informed-size
]
turtles-own
[
informed?
]
to setup
clear-all
nw:load-graphml "JK_nachnamen.graphml"
ask turtles [ set size 1.5 ]
layout-radial turtles links turtle 61
ask turtles [set color red]
ask turtles [set shape "dot"]
ask links [set color grey + 1.5]
ask patches [set pcolor white]
ask turtles [set label-color black]
ask turtles [set informed? false]
ask turtle 72
[
set informed? true
set color green
]
set num-informed 1
set informed-size 2
reset-ticks
nw:save-graphml "JKnachnamennetlogo.graphml"
end
to spread
if (count turtles with [informed? = true] > .7 * count turtles) [stop]
ask turtles with [ informed? = true ]
[
ask link-neighbors with [not informed?]
[
if (random-float 1 <= 0.01)
[
set informed? true
show-turtle
set color green
]
]
]
set num-informed count turtles with [informed? = true]
tick
end
Thank you a lot.
I am a little unclear so am giving bits of different answers for different situations.
If the turtles are different each time, what do you mean by 'the same turtle'. For example, do you mean the turtle in a particular position? If so, you could select the turtle on the appropriate patch.
If it doesn't matter which particular turtle it is (just that it's the same turtle), then the simplest approach is to set the random-seed. Then every time you run any random process (including choosing one-of the turtles to select the starting infection, or ask turtles to do something), NetLogo will use the same chain of random numbers. Of course, if you are still building your model, then adding new pieces of code that change how many calls are made to the random number generator will lead to a different chain, but rerunning with the same code will give the identical run.
You may need to use with-local-randomness and random-seed new-seed if you want to have some parts actually change.
The problem is that nw does not store the WHO variable this is to avoid conflict with already existing turtles in a model.
A work-around would be assigning each turtle a separate id variable and setting that to who.
turtles-own [informed? id]
in turtles creation asign them each the id thus
set id who
you may want to write a conversion procedure like this
to convert
nw:load-graphml "JK_nachnamen.graphml"
ask turtles [set id who]
nw:save-graphml file-name "JK_nachnamen(id).graphml"
end
and use the copy. Of course you would not use
turtle 74
but
one-of turtles with [id = 74]
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).