The dynamics of epidemics are poorly understood with, typically, the general population parroting the exponential growth model of Malthus that was debunked by Darwin. Statistical modelling by Farr had...

I'm working on a simple virus model in NETlogo, and attempting to integrate spatial data. I'm hoping I can limit the "agents" to these polygons and base the number of them off of my population data. Currently, I've modified an existing model and have been able to add my polygons (and associated attribute information) by copying the code from the provided "segregation" model in the NETlogo library. to setup clear-all setup-constants setup-turtles update-global-variables update-display gis:load-coordinate-system "data/LA_Harbor_Region.prj" set city-dataset gis:load-dataset "data/LA_Harbor_Region.shp" gis:set-world-envelope gis:envelope-of city-dataset ;;copy the color information to patches (converting vector to raster) gis:apply-coverage city-dataset "SOC" mycolor gis:apply-coverage city-dataset "DISTRICT" DISTRICT ;; each polygon identifies a patch at its centroid, which records the color ;; and population here let n 1 foreach gis:feature-list-of city-dataset [ feature -> let center-point gis:location-of gis:centroid-of feature ask patch item 0 center-point item 1 center-point [ set centroid? true set popu gis:property-value feature "POP65UP" ] set n n + 1 ] It does appear the model was able to read the data to draw the polygons/map, separate the census tracts and apply the color modifiers I requested. However, I am unable to get the model to do little else. This is the code section I believe controls the initial population/location in the "segregation" model with some modifications. ;; Find neighbors using a txt file produced by ArcGIS Polygon Neighbors. ;; Please read NETLOGO FEATURES in info tab for more information. ask patches with [centroid? = true] [ set myneighbors n-of 0 patches ;;empty agentset ] file-close file-open "data/neighbors.txt" while [not file-at-end?] [ let x file-read let y file-read ask patches with [ centroid? = true and DISTRICT = x ] [ set myneighbors (patch-set myneighbors patches with [centroid? = true and DISTRICT = y ]) ] ] file-close ask patches with [centroid? = true] [ if count myneighbors = 0 [print "ERROR"] ] ;;use this line to verify if we get the right neighbors ;ask one-of patches with [centroid? = true] [print myneighbors ask myneighbors [sprout 1]] ;;fill in the color on themap foreach gis:feature-list-of city-dataset [ feature -> if gis:property-value feature "SOC" = "RED" [ gis:set-drawing-color 15 gis:fill feature 2.0 ] if gis:property-value feature "SOC" = "BLUE" [ gis:set-drawing-color 95 gis:fill feature 2.0 ] if gis:property-value feature "SOC" = "GREY" [ gis:set-drawing-color 7 gis:fill feature 2.0 ] if gis:property-value feature "SOC" = "BLACK" [ gis:set-drawing-color 99 gis:fill feature 2.0 ] if gis:property-value feature "SOC" = "YELLOW" [ gis:set-drawing-color 45 gis:fill feature 2.0 ] ] ;; Draw boundary gis:set-drawing-color white gis:draw city-dataset 1 ;; Creating households ask patches with [DISTRICT > 0] [set occupied? false] let y 1 while [y

From June 29 to July 1, 2026, the NetLogo Center at Northwestern University welcomed researchers and educators to Chicago for the very first NetLogo user conference. As the go-to platform for individu...

I am trying to create turtles within postcode boundary. I have imported the postcode shapefile in NetLogo and applied postcodes to the patches. I could create one turtle within each postcode boundary but struggling to figureout how can I create number of turtles within each postcode boundary according to the NUM_AGENT field from the attribute table of postcode shapefile? The following code can successfully create one turtle per postcode. to setup ca reset-ticks set res_town gis:load-dataset "Projected_data/town_data.shp" set studyextent gis:load-dataset "Projected_data/Apr.asc" resize-world -924 924 -800 800 ; 0 gis:width-of (studyextent) - 1 0 gis:height-of (studyextent) - 1 gis:set-drawing-color grey gis:draw res_town 1 gis:draw studyarea 1 gis:set-world-envelope (gis:envelope-union-of (gis:envelope-of res_town) (gis:envelope-of studyextent) ) gis:set-coverage-minimum-threshold 0.0000001 gis:apply-coverage res_town "POA" postcode ask patches [ ifelse (postcode = 0) [ ] [ set postcode 0] ] ; NaN fix let respatches patches with [postcode > 0 ] ask respatches [ set postcode round (postcode) set pcolor 2 + postcode * 0.75 ] let postcodelist ([postcode] of respatches) let uniquepostcodelist remove-duplicates postcodelist let sortedlist sort uniquepostcodelist print length sortedlist print sortedlist ;; create turtle for each postcode foreach sortedlist [ x -> ask one-of respatches with [postcode = x] [sprout 1 [set shape "person" set size 15 ]] ] end I am not sure how to add a number of turtles per postcode according to NUM_TURTLES field from the postcode shapefile. I tried using gis:create-turtles-inside-polygon command instead of gis:apply-coverage but when I type the command gis:create-turtles-inside it gives an error saying nothing named gis:create-turtles-inside has been defined. I am using exactly the same code as mentioned in the example. foreach gis:feature-list-of res_town [ res-postcode -> gis:create-turtles-inside res-postcode beekeepers 1 ]

THe Netlogo Center is running their first in person conference at the end of June in Chicago (info and registration). It's an event I'm looking forward to attending and also to be presenting at. I've ...