Код бизнес-модели Netlogo в главе 10. 4 моделей Railsback и Grimm, на основе агентов и отдельных моделей

Question

Я использую примеры из книги Railsback и Grimm (основанное на агентах и ​​индивидуальное моделирование). Я закодировал бизнес-модель с использованием инструкций из главы 10.4. Я могу успешно настроить модель, однако, когда я нажимаю на кнопку ходу, я получаю сообщение об ошибке

"this code can't be run by a patch 
error while turtle 3 running UTILITY-FOR 
    called by procedure REPOSITION 
    called by procedure GO 
    called by Button 'go'" 

Это мой код

patches-own 
[ 
    annual-profit 
    business-risk 
] 

turtles-own 
[ 
    wealth 
] 
to setup 
clear-all 
;initializing the profit 
ask patches 
    [ 
    set annual-profit random 1000 
    set business-risk 1 - risk-probability 
    set pcolor scale-color green annual-profit 0 1000 
    ] 
crt 5 ; created five business spots for test 
    [ 
    setxy random-xcor random-ycor 
    set shape "house" 
    set color red 
    set wealth random 10000] 
    reset-ticks 
end 

to go 
    ask turtles [reposition] 
    tick 
end 

to reposition 
    let potential-destinations neighbors with 
    [not any? turtles-here] 

    ;adding the current patch to the potential-destinations 
    set potential-destinations 
    (patch-set potential-destinations patch-here) 
; Identify the best one of the destinations 
    let best-patch max-one-of potential-destinations 
    [utility-for myself] 

    ;Now move there 
    move-to best-patch 
end 

to-report utility-for [a-turtle] 
    ; a patch-context reporter that calculates utility 
    ; for turtle "a-turtle" in this patch 
    ; first get the turtle's wealth 

    let turtles-wealth [wealth] of a-turtle 
    let profit [annual-profit] of patch-here 
    let risk [business-risk] of patch-here 

; then calculate turtles's utility given its wealth and 
; relevant variables 
    let utility (turtles-wealth + profit * 5) * (risk^ticks) 

    report utility 
end 

Answer 1

Изменить

let profit [annual-profit] of patch-here 
let risk [business-risk] of patch-here 

в

let profit annual-profit 
let risk business-risk 

hth