I have a simple Astar search model that finds the optimal path to a given destination. It operates on all turtles- however, it does so one at a time. I would like to speed up my simulation when having multiple turtles (ships) by having all turtles create/iterate through the search space (find-a-path) at the same time.
Below I have attached a portion of code where i call this. Is there a way I can modify my current code to support this? Any help would be greatly appreciated, thanks.
to find-shortest-path-to-destination
place-turtles
label-destination
ask ships
[
set path find-a-path current-waypoint target-waypoint
set optimal-path path
set current-path path
output-show (word "Shortest Path Length: " length optimal-path " (" "LP: " land-prox "," " LPW: " land-prox-weight ")")
]
end
to-report find-a-path [ source-patch destination-patch]
; initialize all variables to default values
let search-done? false
let search-path []
let current-patch 0
set open []
set closed []
; add source patch in the open list
set open lput source-patch open
; loop until we reach the destination or the open list becomes empty
while [ search-done? != true]
[
ifelse length open != 0
[
; sort the patches in open list in increasing order of their f() values
set open sort-by [[f] of ?1 < [f] of ?2] open
; take the first patch in the open list
; as the current patch (which is currently being explored (n))
; and remove it from the open list
set current-patch item 0 open
set open remove-item 0 open
; add the current patch to the closed list
set closed lput current-patch closed
; explore the neighbours of the current patch
ask current-patch
[
; if any of the neighbours is the destination stop the search process
ifelse any? neighbors with [ (pxcor = [ pxcor ] of destination-patch) and (pycor = [pycor] of destination-patch)]
[
set search-done? true
]
[
; the neighbors should not be obstacles or already explored patches (part of the closed list)
ask neighbors with [ elev <= min-depth and (not member? self closed) and (self != parent-patch) ]
[
; the neighbors to be explored should also not be the source or
; destination patches or already a part of the open list (unexplored patches list)
if not member? self open and self != source-patch and self != destination-patch
[
set pcolor gray + 1
; add the eligible patch to the open list
set open lput self open
; update the path finding variables of the eligible patch
set parent-patch current-patch
set g [g] of parent-patch + 1
set h distance destination-patch
set f (g + h)
]
]
]
if self != source-patch
[
]
]
]
[
; if a path is not found (search is incomplete) and the open list is exhausted
; display a user message and report an empty search path list.
user-message( "A path from the source to the destination does not exist." )
report []
]
]
; if a path is found (search completed) add the current patch
; (node adjacent to the destination) to the search path.
set search-path lput current-patch search-path
; trace the search path from the current patch
; all the way to the source patch using the parent patch
; variable which was set during the search for every patch that was explored
let temp first search-path
while [ temp != source-patch ]
[
ask temp
[
set pcolor white
]
set search-path lput [parent-patch] of temp search-path
set temp [parent-patch] of temp
]
; add the destination patch to the front of the search path
set search-path fput destination-patch search-path
; reverse the search path so that it starts from a patch adjacent to the
; source patch and ends at the destination patch
set search-path reverse search-path
; report the search path
report search-path
end
Related
Here-below is the code for opening a file, reading it and writing it into a list (inspired from another discussion) :
to setup
reset-timer
; first, we load the database file
; We check to make sure the file exists first
ifelse ( file-exists? "AT_data.txt" )
[
; We are saving the data into a list, so it only needs to be loaded once.
set AT-data []
file-open "AT_data.txt"
while [ not file-at-end? ]
[
; file-read gives variables stored in a double list
; Each iteration we append the next three-tuple to the current list: ID AT1 AT2
set AT-data sentence AT-data (list (list file-read file-read file-read))
]
user-message "File loading complete!"
file-close
;; when adding this, the procedure is running endlessly, to be checked
;; ask patches [ assign-data ]
]
[ user-message "There is no AT_data.txt file in current directory!" ]
file-close-all
print timer
end
As I wrote as a comment, when I call the next procedure [assign-data], the procedure [assign-data] runs endlessly. I setup a timer in the [assign-data] procedure and I see that it is running over and over again. When I run [assign-data] on its own, it is working appropriatly, only once.
I tried with a stop after [assign-data] but it is not working.
There must be something that I did not get yet about the use of Netlogo, do you know what it is ?
Here is the code of the assign-dataprocedure (there are 2 choices, the second is running faster)
to assign-farmers1
reset-timer
ask patches with [seed = 1] [
set death last (first (filter [current-inner-list -> (item 0 current-inner-list = ID_farm)] AT-data))
set age item 1 (first (filter [current-inner-list -> (item 0 current-inner-list = ID_farm)] AT-data))
]
print timer
end
to assign-data2
reset-timer
ask patches with [seed = 1] [
let i 1
while [i < length AT-data] [
let current-inner-list item i AT-data
ifelse (ID_farm = item 0 current-inner-list)
[ set age item 1 current-inner-list set death item 2 current-inner-list
stop]
[ set i i + 1 ]
]
]
print timer
end
-> that lead me to another question : how to stop a simulation from running endlessly ? I tried with stop in the command center but it is not working.
Thanks for you time.
HERE IS A REPRODUCIBLE EXAMPLE
(not sure if I should leave the beginning of the question)
AT_data.txt is a file made of 3 col where the first goes from 1 to 100, second and third are just random numbers.
globals [
AT-data
]
patches-own [
ID
AT1
AT2
seed
]
to setup
;; here I just create patches with different values that also appear in the list
ca
ask patches [ set seed random 10 set ID random 100
ifelse (seed = 4)
[ set pcolor orange] [set pcolor white]
]
end
to load
reset-timer
; first, we load the database file
; We check to make sure the file exists first
ifelse ( file-exists? "AT_data.txt" )
[
; We are saving the data into a list, so it only needs to be loaded once.
set AT-data []
file-open "AT_data.txt"
while [ not file-at-end? ]
[
; file-read gives variables stored in a double list
; Each iteration we append the next three-tuple to the current list: ID AT1 AT2
set AT-data sentence AT-data (list (list file-read file-read file-read))
]
user-message "File loading complete!"
file-close
;; when adding this, the procedure is running endlessly, to be checked
ask patches [ assign-data ]
stop
]
[ user-message "There is no AT_data.txt file in current directory!" ]
file-close-all
print timer
end
to assign-data
reset-timer
ask patches with [seed = 4] [
let i 1
while [i < length AT-data] [
let current-inner-list item i AT-data
ifelse (ID = item 0 current-inner-list)
[ set AT1 item 1 current-inner-list set AT2 item 2 current-inner-list
stop]
[ set i i + 1 ]
]
]
print timer
end
Are you sure the run is endless and not exponential? You ask patches to assign-data and in assign-data you use ask patches again. That means that every single patch is checking every single patch and letting the qualified patch go through the loop, which can take a while.
I have turtles (patients), and they can only use only one bed each (white patch). Since patients are randomly generated in a waiting room (green patches), sometimes two or more of them get at the same distance and therefore they find the same patch as its target. I tried to add an attribute to the patch with the purpose of assigning that particular bed to a specific patient. The idea is something like this (please indulge on the ugly code, I'm learning :P):
globals [
waitxmax
waitxmin
waitymax
waitymin
box
]
breed [ patients patient ]
patients-own [ target ]
patches-own [ assigned ]
to setup-wait-room
set waitxmax -15
set waitxmin 15
set waitymax 11
set waitymin 15
ask patches with [
pxcor >= waitxmax and
pxcor <= waitxmin and
pycor >= waitymax and
pycor <= waitymin
] [ set pcolor green ]
end
to setup-beds
let cmy 7
let cmx 15
let dst 3
let nbox 7
ask patch cmx cmy [ set pcolor white ]
let i 1
while [ i < nbox ] [
ask patch (cmx - dst) cmy [ set pcolor white ]
set i i + 1
set cmx cmx - dst
]
ask patches with [ pcolor = white ] [ set assigned false ]
set box patches with [ pcolor = white ]
end
to setup-patients
create-patients start-patients [
set shape "person"
set target nobody
move-to one-of patches with [ pcolor = green ] ]
end
to setup [
clear-all
setup-wait-room
setup-beds
reset-ticks
]
to go
ask patients [ go-to-bed ]
tick
end
to go-to-bed
let _p box with [ self != [ patch-here ] of myself ]
if target = nobody [
set target min-one-of _p [ distance myself ]
ask target [ set assigned myself ]
]
;;; FIXME
if ([ assigned ] of target) != self [ show "not true" ]
if target != nobody [
face target
fd 1
]
end
When I print the two sides of the comparison below FIXME, from the command center I actually get the expected result. For example: both patient 0 and patient 1 have the same target (patch -3 7), but that patch is assigned to (patient 0). I would have expected that comparison to force patient 1 to get a new target since the bed doesn't have his name (I haven't written that code yet), but it always evaluates to true. This is more notorious as more patients I add over available beds (if no beds available, they should wait as soon as one gets free).
When inspecting trough the interface I also see that the patch -3 7 says (patient 0), so I don't know what's happening. Command center example:
observer> show [ assigned ] of patch -3 7
observer: (patient 0)
observer> if ([ assigned ] of patch -3 7) = [self] of patient 0 [ show "true" ]
observer: "true"
observer> if ([ assigned ] of patch -3 7) = [self] of patient 1 [ show "true" ]
;;;; SETUP AND GO
(patient 0): (patch -3 7)
(patient 0): (patient 0)
(patient 0): "true"
(patient 2): (patch 12 7)
(patient 2): (patient 2)
(patient 2): "true"
(patient 1): (patch -3 7)
(patient 1): (patient 1)
(patient 1): "true"
Maybe I'm just overthinking this and there are is a simpler way to assign a bed to a patient and vice versa?
There seems to be a chunk or two missing from your code above (I can't copy-paste and run it), so please have a look at the option below.
This version works by having a single place to store the 'claimed' beds- in the turtle variable. Since the turtle variables can be queried as a list using of, a bed-less turtle can check if there are any beds that are not already present in that list and, if so, claim one.
turtles-own [ owned-bed ]
to setup
ca
ask n-of 5 patches [
set pcolor green
]
crt 10 [
set owned-bed nobody
claim-unclaimed-bed
if owned-bed != nobody [
print word "I own the bed " owned-bed
]
]
reset-ticks
end
to claim-unclaimed-bed
; If I have no bed
if owned-bed = nobody [
; Pull the current owned beds for comparison
let all-owned-beds [owned-bed] of turtles
; Pull those beds that are green AND are not found in 'all-owned-beds'
let available-beds patches with [
pcolor = green and not member? self all-owned-beds
]
; If there are any beds available, claim one
ifelse any? available-beds [
set owned-bed one-of available-beds
] [
; If there are none available, print so
print "There are no available beds."
]
]
end
Edit: Forgot the actual question title- to actually move to their owned-bed (if they have one) in the example above, they simply face it and move how you like- for example:
to go
ask turtles with [ owned-bed != nobody ] [
ifelse distance owned-bed > 1 [
face owned-bed
fd 1
] [
move-to owned-bed
]
]
tick
end
Edit: added complexity
Ok, for an added element of severity, you will likely want to avoid using multiple with [ ... = x statements, and instead to use a primitive called min-one-of which returns the agent with the minimum value of some reporter. Then, you want to tell NetLogo to keep asking the next most severe and the next most severe, etc. One way to do this is with a while loop, which basically says "While this condition is met, continue evaluating the following code." Be careful with while loops- if you forget to write your code such that eventually the condition is no longer true, the while loop will just continue running until you will eventually Tools > Halt your model (or, as has happened to me with a large model, NetLogo crashes).
I've reworked the code (much of what was above is unchanged) to include such a while loop. Note as well that, since the model needs to check which beds are available multiple times, I've made that code into a to-report chunk to condense / simplify.
turtles-own [ owned-bed severity ]
to setup
ca
ask n-of 5 patches [
set pcolor green
]
crt 10 [
set owned-bed nobody
set severity random-float 10
]
let current-available-beds report-available-beds
while [any? current-available-beds] [
; From the turtles with no bed, ask the one with the lowest severity number to
; claim an unclaimed bed. Then, reset the current-available-beds
ask min-one-of ( turtles with [owned-bed = nobody] ) [ severity ] [
claim-unclaimed-bed
if owned-bed != nobody [
show ( word "I have a severity of " severity " so I am claiming the bed " owned-bed )
]
]
set current-available-beds report-available-beds
]
reset-ticks
end
to-report report-available-beds
let all-owned-beds [owned-bed] of turtles
report patches with [
pcolor = green and not member? self all-owned-beds
]
end
to claim-unclaimed-bed
; If I have no bed
if owned-bed = nobody [
let available-beds report-available-beds
; If there are any beds available, claim one
ifelse any? available-beds [
set owned-bed one-of available-beds
] [
; If there are none available, print so
print "There are no available beds."
]
]
end
I would like to remove a doubt and have some help.
I have a closed world of 600X600 patches. Each patch spawns a turtle (using the sprout command). Each turtle makes a series of moves and returns a value for its home patch. I would like to have the following result: know which turtle was in each patch in the world and export this result in table form in .csv
I created a list for this. But, NetLogo is running for a while and then it closes and doesn't finish the model. And so I think if I create a table it should work. The question is: will creating a table solve the problem of the model not running? And if so, how can I create a table by generating an output from that table in .csv? But, I haven't found a NetLogo command that I can create a table to adjust my code to.
Any tip is very welcome. I thank the attention
globals [ edge-size output-turtle-visits ]
patches-own [ turtle-visits ]
to setup
ca
random-seed 1
set edge-size 599
set-patch-size 1.2
resize-world 0 edge-size 0 edge-size
let pcolors []
set pcolors [ 85 95 ]
ask patches [ sprout 1 ]
ask patches [
set turtle-visits n-values count turtles [0]
set pcolor item (random 2) pcolors
]
reset-ticks
end
to go
ask turtles [
rt random 360
fd 1
]
ask patches [
foreach [who] of turtles-here [ id ->
let current-num-visits item id turtle-visits
set turtle-visits replace-item id turtle-visits (current-num-visits + 1)
]
]
end
to output
file-open ( output-turtle-visits )
file-print ( word "id_turtle;my_xcor;my_ycor;turtle_visits" )
foreach sort patches
[
t ->
ask t
[
file-print ( word self " ; " xcor " ; " ycor " ; " turtle-visits )
]
]
file-print "" ;; blank line
file-close
end
Situation: I have a code that exports turtle coordinates according to the code below:
to path
file-open (word fileName ".csv")
file-print (word self xcor " " ycor)
file-close
end
The result is something like:
(turtle 1)[1 1 1 1 1 2] [4 4 4 2 1 5]
Question: How can I export this same list, but with its items separated by commas?
From [1 2 1 1 1] to [1,2,1,1,1], for example.
Thanks in advance
If you are trying to process this in R or something after the fact, I'd recommend potentially reporting in long format (ie, each line indicates a turtle, a tick [or similar], and the coordinates)- I find it simpler to process.
To answer your actual question- one way would be to manually collapse each list of coordinates into a string separated by commas. For example, see the toy model below.
Simple setup:
extensions [csv]
globals [ test ]
turtles-own [ xcor-list ycor-list ]
to setup
ca
crt 10 [
set xcor-list []
set ycor-list []
]
repeat 5 [
ask turtles [
rt random 90 - 45
fd 1
set xcor-list lput pxcor xcor-list
set ycor-list lput pycor ycor-list
]
]
reset-ticks
end
This reporter is what's actually doing the work of collapsing the list into a simple string for output:
to-report collapse-string-list [str-list]
report reduce word ( sentence map [ str -> word str ", " ] but-last str-list last str-list )
end
And this chunk pulls the desired turtle variables into a list of lists, calls the collapse-string-list reporter on them, then exports to a csv:
to output-coord-file
let all-turtles sort turtles
; Pull coordinates from each turtle
let who-coord-list map [
current-turtle ->
(list
[who] of current-turtle
collapse-string-list [xcor-list] of current-turtle
collapse-string-list [ycor-list] of current-turtle
)] all-turtles
; Add headers
set who-coord-list fput ["who" "x" "y"] who-coord-list
; Export
csv:to-file "toy.csv" (map [ row -> (map [i -> (word i)] row ) ] who-coord-list)
end
Output:
I am simulating the spread of a virus across a small world network in netlogo. Using the existing model netlogo offers of a small world network where nodes can connect with other nodes using the 'Rewire One' button on the interface I am trying to get it so that if an initially infected individual gets rewired with a susceptible individual the virus will then transfer to that individual and the turtles color will update to red.
Here is the code im using to rewire one turtle with another:
to rewire-one
if count turtles != num-nodes [
setup
]
set rewire-one? true
set rewire-all? false
let potential-edges links with [ not rewired? ]
ifelse any? potential-edges [
ask one-of potential-edges [
let node1 end1
;; if "a" is not connected to everybody
if [ count link-neighbors ] of end1 < (count turtles - 1)
[
;; find a node distinct from node1 and not already a neighbor of node1
let node2 one-of turtles with [ (self != node1) and (not link-neighbor? node1) ]
;; wire the new edge
ask node1 [ create-link-with node2 [ set color cyan set rewired? true ] ]
ask links
[ reed-frost-children]
ask links
[ increment-children ]
set number-rewired number-rewired + 1 ;; counter for number of rewirings
;; remove the old edge
die
]
]
;;I am then using the reed-frost function as the force of infection which can be seen below
to reed-frost-children
ask children with [ child-sus = 1]
[
set num-infected-neighbours length filter [[ child-infected = 1] of ?]
[other-end] of my-links with [not rewired?] ;; i.e not closed? i.e open
set force-of-infection 1 - (1 - prob-infection-child) ^ num-infected- neighbours
if(random-float 1 <= force-of-infection)
[
set child-sus 0
set child-inncubated 1
set child-infected 0
set child-almost-infected 0
set child-recovered 0
set inncubation-period 100
show-turtle
set color orange
set size 1
ask link-neighbors with [ child-infected = 1]
[
ask my-links
[
set color orange show-link
ask other-end
[
set color orange
]
]
]
ask my-links [set closed? false] ;; closed i.e. not open
]
]
However the virus is not transmitting when an infected rewires with a susceptible. Any ideas?