所以我只是在研究netlogo库中的2通道流量模型。我对代码进行了一些更改，以使汽车可以双向行驶。但是我不知道如何在正确的位置产卵它们。谁能帮我？我认为这与create-mice和create-frogs中的pycor有关。谢谢。
breed [mice mouse]
breed [frogs frog]
globals [
selected-car ; the currently selected car
lanes ; a list of the y coordinates of different lanes
]
turtles-own [
speed ; the current speed of the car
top-speed ; the maximum speed of the car (different for all cars)
target-lane-up ; the desired lane of the car
target-lane-down
patience ; the driver's current level of patience
]
to setup
clear-all
draw-road
create-or-remove-cars
set selected-car one-of turtles
ask selected-car [ set color red ]
reset-ticks
end
to create-or-remove-cars
let road-patches patches with [ member? pycor lanes ]
if number-of-cars > count road-patches [
set number-of-cars count road-patches
]
create-mice (number-of-cars / 2 - count mice) [
set color car-color
set shape "car"
move-to one-of free road-patches
set target-lane-up pycor
set heading 90
set top-speed 0.5 + random-float 0.5
set speed 0.5
set patience random max-patience
]
create-frogs (number-of-cars / 2 - count frogs) [
set color car-color
set shape "car flipped"
move-to one-of free road-patches
set target-lane-down pycor
set heading -90
set top-speed 0.5 + random-float 0.5
set speed 0.5
set patience random max-patience
]
if count turtles > number-of-cars [
let n count turtles - number-of-cars
ask n-of n [ other turtles ] of selected-car [ die ]
]
end
to-report free [ road-patches ] ; turtle procedure
let this-car self
report road-patches with [
not any? turtles-here with [ self != this-car ]
]
end
to draw-road
ask patches [
set pcolor green - random-float 0.5
]
set lanes n-values number-of-lanes [ n -> number-of-lanes - (n * 2) - 1 ]
ask patches with [ abs pycor <= number-of-lanes ] [
set pcolor grey - 2.5 + random-float 0.25
]
draw-road-lines
draw-line-middle
end
to draw-road-lines
let y (last lanes) - 1 ; start below the "lowest" lane
while [ y <= first lanes + 1 ] [
if not member? y lanes [
ifelse abs y = number-of-lanes
[ draw-line y yellow 0 ] ; yellow for the sides of the road
[ draw-line y white 0.5 ] ; dashed white between lanes
]
set y y + 1 ; move up one patch
]
end
to draw-line [ y line-color gap ]
create-turtles 1 [
setxy (min-pxcor - 0.5) y
hide-turtle
set color line-color
set heading 90
repeat world-width [
pen-up
forward gap
pen-down
forward (1 - gap)
]
die
]
end
to draw-line-middle
create-turtles 1
[
set heading 90
set color yellow
pen-down
fd world-width
die
]
end
to go
create-or-remove-cars
ask mice [ move-forward ]
ask frogs [move-backward]
ask mice with [ patience <= 0 ] [ choose-new-lane ]
ask frogs with [ patience <= 0 ] [ choose-new-lane ]
ask mice with [ ycor != target-lane-up ] [ move-to-target-lane ]
ask frogs with [ ycor != target-lane-down ] [ move-to-target-lane ]
tick
end
to move-forward
set heading 90
speed-up-car ; we tentatively speed up, but might have to slow down
let blocking-cars other turtles in-cone (1 + speed) 180 with [ y-distance <= 1 ]
let blocking-car min-one-of blocking-cars [ distance myself ]
if blocking-car != nobody [
set speed [ speed ] of blocking-car
slow-down-car
]
forward speed
end
to move-backward
set heading -90
speed-up-car
let blocking-cars other turtles in-cone (1 + speed) 180 with [ y-distance <= 1 ]
let blocking-car min-one-of blocking-cars [ distance myself ]
if blocking-car != nobody [
set speed [ speed ] of blocking-car
slow-down-car
]
forward speed
end
to slow-down-car
set speed (speed - deceleration)
if speed < 0 [ set speed deceleration ]
set patience patience - 1
end
to speed-up-car
set speed (speed + acceleration)
if speed > top-speed [ set speed top-speed ]
end
to choose-new-lane ; turtle procedure
let other-lanes remove ycor lanes
if not empty? other-lanes [
let min-dist min map [ y -> abs (y - ycor) ] other-lanes
let closest-lanes filter [ y -> abs (y - ycor) = min-dist ] other-lanes
set target-lane-up one-of closest-lanes
set target-lane-down one-of closest-lanes
set patience max-patience
]
end
to move-to-target-lane
set heading ifelse-value (target-lane-up < ycor) [ 180 ] [ 0 ]
let blocking-mice other mice in-cone (1 + abs (ycor - target-lane-up)) 180 with [ x-distance <= 1 ]
let blocking-mouse min-one-of blocking-mice [ distance myself ]
ifelse blocking-mouse = nobody [
forward 0.2
set ycor precision ycor 1 ; to avoid floating point errors
] [
ifelse towards blocking-mouse <= 180 [ slow-down-car ] [ speed-up-car ]
]
set heading ifelse-value (target-lane-down < ycor) [ 180 ] [ 0 ]
let blocking-frogs other frogs in-cone (1 + abs (ycor - target-lane-down)) 180 with [ x-distance <= 1 ]
let blocking-frog min-one-of blocking-frogs [ distance myself ]
ifelse blocking-frog = nobody [
forward 0.2
set ycor precision ycor 1 ; to avoid floating point errors
] [
ifelse towards blocking-frog <= 180 [ slow-down-car ] [ speed-up-car ]
]
end
to-report x-distance
report distancexy [ xcor ] of myself ycor
end
to-report y-distance
report distancexy xcor [ ycor ] of myself
end
to select-car
if mouse-down? [
let mx mouse-xcor
let my mouse-ycor
if any? turtles-on patch mx my [
ask selected-car [ set color car-color ]
set selected-car one-of turtles-on patch mx my
ask selected-car [ set color red ]
display
]
]
end
to-report car-color
report one-of [ blue sky cyan yellow green] + 1.5 + random-float 1.0
end
to-report number-of-lanes
report 4
end
; Copyright 1998 Uri Wilensky.
; See Info tab for full copyright and license.