I have a model where patches have the value of "habitat" and I have a csv file of animal selection ratios. The goal is that I want each agent to survey the habitats within their next step to decide where to move.
The code is as follows.
to move_females_test
let this_step (one-of step_length_lsf / patch-length)
let available [habitat] of patches in-radius this_step
let unique-habitats remove-duplicates available
print available
print unique-habitats
ifelse length unique-habitats = 1 [
; If there is only one unique habitat, move as per the existing code
set heading (one-of turning_angles_lsf * 100)
fd this_step
] []
end
so for each tick the turtle generates something like this
[Pastures Pastures Pastures Pastures Pastures]
in which case there is no need to decide - so they move randomly. Or something like this
[Pastures Pastures Pastures Scrub Arable]
In which case I want them to draw from a list called selection I have initalised and populated with values from a habitat selection model. The list looks like this, as an example.
[[Pastures 1] [Pastures 1] [Arable 2.485988192] [Scrub 0.684336963] [Arable 0.994063271] [Pastures 1.009595509]
What I would like to do - is to match the habitats that present themselves in the unique-habitats list with a randomly selected matching habitat in the selection list and then select the highest value to decide where to go.
i.e in pseduocode.
to move_females_test
let this_step (one-of step_length_lsf / patch-length)
let available [habitat] of patches in-radius this_step
let unique-habitats remove-duplicates available
print available
print unique-habitats
ifelse length unique-habitats = 1 [
; If there is only one unique habitat, move as per the existing code
set heading (one-of turning_angles_lsf * 100)
fd this_step
]
[let ratios [foreach habitat in unique-habitats [select one-of habitat in select]
;ratio will look like this
;[[Pastures 1] [Arable 0.91]]
let sorted-ratios sort-by [[- item 1 ?] of ?] ratios
let highest-ratio first sorted-ratios
let target-patch one-of patches with [habitat = item 0 highest-ratio]
set heading target-patch
fd this_step
]
end
I always find lists in a list somehow nasty to handle in NetLogo. Especially in your case where they contain two different variable types. But I think I found a solution to your problem. Not sure if this is the most efficient/concise but...
to move_females_test
let this_step (one-of step_length_lsf / patch-length)
let available [habitat] of patches in-radius this_step
let unique-habitats remove-duplicates available
print available
print unique-habitats
ifelse length unique-habitats = 1 [
; If there is only one unique habitat, move as per the existing code
set heading (one-of turning_angles_lsf * 100)
fd this_step
][
let best-habitat best-habitat-REP selection unique-habitats
let target-patch one-of patches in-radius this_step with [habitat = best-habitat]
set heading target-patch
fd this_step
end
to-report best-habitat-REP [selection unique-habitats]
; initallize sperate list for selection habitats and their values
let selection-habitats []
let selection-values []
; extract habitats and their values from selection into these variables
foreach selection [
hab ->
set selection-habitats lput item 0 hab selection-habitats
set selection-values lput item 1 hab selection-values
]
; initalize a list for the randomly selected habitats from the selection
let selected-habitats []
; for each unique habitat
foreach unique-habitats [
uhab ->
; we determine the index of all items of the selection that matches (see all-items-REP function below)
let idx-uhab-in-selection all-items-REP selection-habitats uhab
; if at least one entry of the unique habitat exists in the selection
if not empty? idx-uhab-in-selection [
; we randomly pick one from all the matching entries
set selected-habitats lput one-of idx-uhab-in-selection selected-habitats
]
]
; initialize a list for the values of the selected habitats
let selected-values []
; extract the values of the selected habitats from the selection
foreach selected-habitats [
current-habitat ->
set selected-values lput item current-habitat selection-values selected-values
]
; from all these selected values we find the maximum
let idx-max-value position max selected-values selected-values
; and find the according index of this value in the selection
let final-idx-in-selection item idx-max-value selected-habitats
report item 0 item final-idx-in-selection selection
end
;; Helper function to find all elements that match (the item reporter only reports the
;; first matching value)
to-report all-items-REP [list-to-search item-to-find]
; initialize counter
let i 0
; initialize list with indices
let idx-item []
; loop through list
foreach list-to-search [
current-list-item ->
; check if value matches, and append its index if it matches
if current-list-item = item-to-find [set idx-item lput i idx-item]
set i i + 1
]
report idx-item
end