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新手,在看netlogo自带的例子时,有几行程序看不懂,希望高手能够指点。
" b# b4 E2 |# u3 J6 | ~netlogo自带的social science--traffic grid这一例子当中,: J1 Z' ^# R8 I8 Y8 j W( O9 Q! Z
globals- @7 L& h- _; n- }. `* {
[
o- B3 W% N7 b$ u7 r+ j grid-x-inc ;; the amount of patches in between two roads in the x direction) L3 V9 @9 U7 o9 |+ S
grid-y-inc ;; the amount of patches in between two roads in the y direction
5 a) X9 ]4 X% c acceleration ;; the constant that controls how much a car speeds up or slows down by if' O) R$ @+ n7 R" \' Y! W
;; it is to accelerate or decelerate$ ^* H2 N/ l9 T
phase ;; keeps track of the phase0 b+ ~ r0 n5 m! W
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
& K) o. S2 y0 y current-light ;; the currently selected light' s5 N% _1 J8 O& N+ c, r- S
& k# Z# }+ G9 [" A% Z! q" S ;; patch agentsets. ~# r& V9 W0 O- n$ i8 N
intersections ;; agentset containing the patches that are intersections* K. A* l w8 V0 X
roads ;; agentset containing the patches that are roads
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turtles-own; O7 y4 ~# i4 [: f* ?- v
[
; V) g$ L/ W a: K6 b speed ;; the speed of the turtle: g: _) {9 Y9 K7 m6 F3 W& y
up-car? ;; true if the turtle moves downwards and false if it moves to the right
. Q7 H r6 v$ P5 w; Z* k wait-time ;; the amount of time since the last time a turtle has moved
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9 R4 |( {' a& C5 a s1 c( l Zpatches-own% X" U, z" O" L
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intersection? ;; true if the patch is at the intersection of two roads6 p+ X" }- G Y8 l4 _" _
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 H! _( ^+ {$ @8 M; q. h4 c ;; false for a non-intersection patches.
- E& @. m: e! ^& y6 J( V8 O my-row ;; the row of the intersection counting from the upper left corner of the
+ Z3 b( o1 T* ~: m# B ;; world. -1 for non-intersection patches.
+ y2 z: Q0 n" a1 {" V5 u my-column ;; the column of the intersection counting from the upper left corner of the9 Q# t) D' o$ m
;; world. -1 for non-intersection patches./ N/ A: s: o5 v2 `1 w
my-phase ;; the phase for the intersection. -1 for non-intersection patches. d) e# d5 k& k X
auto? ;; whether or not this intersection will switch automatically.
, u9 v: W( Y/ m& y' O* w. X, N ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& z8 G5 g- _. ?
;; Setup Procedures ;;& y: z' e: C6 _3 b' g
;;;;;;;;;;;;;;;;;;;;;;6 V2 Y a5 o' B9 Q4 U4 V
( M4 s5 K1 D+ p; B# w;; Initialize the display by giving the global and patch variables initial values.( e3 i6 A m: A5 R `
;; Create num-cars of turtles if there are enough road patches for one turtle to0 [6 |" l' P' [& n9 T' u- p( k
;; be created per road patch. Set up the plots.
+ K" s& c* T2 j( y( Ato setup% f5 R( t9 A3 T ^( W" q6 \
ca
& b( Y5 S4 E. M( K setup-globals+ ?0 [) W' j$ }% F g/ g4 e
. N0 z& X+ ]# c ;; First we ask the patches to draw themselves and set up a few variables; r7 _; Y9 J, a0 q( V
setup-patches5 O' t. `! |0 B
make-current one-of intersections" t- q+ D* D6 t$ t# b
label-current
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set-default-shape turtles "car"8 W1 ]1 q0 S7 X0 L
# f( g3 }9 S8 i5 V if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
6 `' C* Y+ c# |. t6 x+ Z( p "road. Either increase the amount of roads "
' ]3 h3 h, F1 O; P! }" ]( ^ "by increasing the GRID-SIZE-X or "3 L2 L: K) s2 n* C# l
"GRID-SIZE-Y sliders, or decrease the "
7 H# y- f, u* w1 h! G5 `2 I "number of cars by lowering the NUMBER slider.\n"$ [0 s; L) \& l9 A) E* ^/ n) L
"The setup has stopped."), ~/ U D8 P0 R% m
stop
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" P5 O: M' \" l, h ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ G" h$ d2 i: D7 e5 y; L
crt num-cars
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9 f/ l" |4 W( ~! v setup-cars
: u; U' n/ j2 `7 Z set-car-color* w" ?2 e6 ~. i' T2 S% L! r( G
record-data- n! Y! i0 R Y% H. \' o: T
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5 Z$ F: F5 h, M6 b ;; give the turtles an initial speed
m+ f6 G7 X! Q0 c7 j7 d3 A ask turtles [ set-car-speed ]7 Y$ N7 {6 X. S
' r* v8 J7 M1 ^$ p; Z* i reset-ticks
6 t$ G2 {2 a; Rend8 S8 b0 }1 S) N6 p
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;; Initialize the global variables to appropriate values6 y0 g' m% v$ I. B
to setup-globals, \# ^9 C; T$ P; R, O( B# ^
set current-light nobody ;; just for now, since there are no lights yet; A" r' y) [ k! Y
set phase 03 q& A9 K) k1 ?( n b$ o
set num-cars-stopped 0
L0 V+ C7 P& D* f/ ]8 | set grid-x-inc world-width / grid-size-x6 M) b3 h+ S: R% E; R( V1 }
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary7 U- b" Y; b* `3 Q k, T
set acceleration 0.099
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5 J* U, T! P9 U: [;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" s$ U3 F6 p: l( o q% l/ f+ y3 e;; and initialize the traffic lights to one setting7 N* H& e$ c8 X" j
to setup-patches- V) u, B# z' U( u/ q. }, m: i
;; initialize the patch-owned variables and color the patches to a base-color6 e# B' c2 k* l, n
ask patches% `/ C& ]$ \" n
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set intersection? false) Q* j* a- A! n$ ^" B
set auto? false3 c. O. }- ?0 e0 P) g- N; l
set green-light-up? true9 z6 ?3 @9 H; C$ k( p' w
set my-row -1
; d) u( e! S& V; p set my-column -1) J1 F( Y- C E$ g! c5 y
set my-phase -1
; C: M k- H; Z set pcolor brown + 3; K6 W8 A1 Q, r5 J4 B" {3 H2 y* f
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;; initialize the global variables that hold patch agentsets. o' E, ]2 `, x! A6 p) S0 y. g
set roads patches with
* x B5 `& b6 Y! M1 X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 f6 f1 `4 j* w" [, N% m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* V# F/ p- c9 J3 a$ R- R
set intersections roads with
2 A' ?) i* H9 }) p, Q, k; O0 s% {( F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" M$ ^# [4 v' Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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1 F1 S/ b& @6 k9 `7 a ask roads [ set pcolor white ]
& X5 \3 D8 h/ i# a4 q setup-intersections; `9 m. P) ?" N* h" x- w
end4 g8 e) m% t: W' S b
其中定义道路的句子,如下所示,是什么意思啊?
" s2 o6 K, u: K6 K5 e+ X, ^) }4 m set roads patches with" T/ b% f# I; _4 P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# @; A8 v+ h4 J1 r& ^% o% y; ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 @$ H x3 `5 ]- j) G5 Q* g谁能帮我解释一下[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0)是什么意思吗? |
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