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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。
' z! B7 q! N, ?% C" C. Tnetlogo自带的social science--traffic grid这一例子当中,
$ e4 K C: Y0 i$ a9 Aglobals: S F$ s3 g$ h7 d
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grid-x-inc ;; the amount of patches in between two roads in the x direction
1 I! e% D: {$ a% ^+ Q# y grid-y-inc ;; the amount of patches in between two roads in the y direction
* n0 p9 }/ D9 u! L- x3 v! ` acceleration ;; the constant that controls how much a car speeds up or slows down by if4 m! p' f1 |* f* X$ j4 J0 C
;; it is to accelerate or decelerate8 \- b- h [3 M6 S+ `3 ^
phase ;; keeps track of the phase
: b) A; x! a1 @* I5 ~* y) Z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# L2 G8 d# v4 @6 b$ M' I9 `. H
current-light ;; the currently selected light' i6 g7 [* l& V! `
7 c- v+ A6 e+ L# o0 E% q! I6 f ;; patch agentsets
( n6 f4 r7 @1 i* l% k3 R% b& X intersections ;; agentset containing the patches that are intersections# J: w5 m3 w2 t) W x% R2 J
roads ;; agentset containing the patches that are roads- z i! y+ N: k4 L4 ~% j
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% `* s0 t7 j+ Tturtles-own
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speed ;; the speed of the turtle
Y0 Y& W, {8 d; i, N7 h, U6 o8 U up-car? ;; true if the turtle moves downwards and false if it moves to the right6 }4 q7 O1 _- d' e- j; I
wait-time ;; the amount of time since the last time a turtle has moved9 g% v9 m$ ~1 J: l
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patches-own
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! o: p# q! Q8 ~; S0 |' T8 _/ v intersection? ;; true if the patch is at the intersection of two roads4 q. K' k+ ^, p* S* R- R5 D
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 s& F/ o a9 m* W" L( ^ ;; false for a non-intersection patches.
6 K* [& `% X/ T& u my-row ;; the row of the intersection counting from the upper left corner of the+ [* ]2 k4 ~9 u/ B, b, _7 F `& v
;; world. -1 for non-intersection patches.3 i% r3 d; f) x8 a5 I7 U
my-column ;; the column of the intersection counting from the upper left corner of the
6 X. ]. R8 ?" m1 D/ x% r5 b ;; world. -1 for non-intersection patches.+ o" y& F. q! y$ r2 A: Z3 B
my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 y# d" G; q2 j8 O$ T
auto? ;; whether or not this intersection will switch automatically.
& T% ~* c1 a. A' z/ m7 m6 M) S0 j ;; false for non-intersection patches.
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8 j" d4 \ v% B+ t+ {;;;;;;;;;;;;;;;;;;;;;;
; Y+ S9 n) [* i+ m% J, L;; Setup Procedures ;;( l5 a0 @& I% m# h' F9 m- a2 Q
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' |+ z" F7 ]( l/ k! _- h9 y4 |;; Initialize the display by giving the global and patch variables initial values.
" O+ {2 i; v8 P;; Create num-cars of turtles if there are enough road patches for one turtle to1 k5 z9 J7 m5 w
;; be created per road patch. Set up the plots.
! ], F' Y h% @+ m+ h2 M) Tto setup
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/ l! T. t9 g, z' R/ T& c& t5 i+ _ setup-globals
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0 f3 `. H1 \, V/ v, b) v ;; First we ask the patches to draw themselves and set up a few variables
3 U' G$ _+ _' F6 C z+ R$ o setup-patches
N) u7 C! f( f j' B6 D; _9 l make-current one-of intersections
! i4 h' \% ^) z$ H' w5 z) O. Q label-current8 v8 a* |' Q* j: i
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set-default-shape turtles "car"
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& m: C7 g- B& F; \, t if (num-cars > count roads)' O- B; @8 O, B: S. l* Z$ k
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! y* a4 \! z( I3 s% m& r user-message (word "There are too many cars for the amount of "+ F6 v- Y3 R2 I8 ^+ ^8 e
"road. Either increase the amount of roads "
' ] ]4 K; N; s! Z8 b "by increasing the GRID-SIZE-X or "
7 {, k! s' F! v3 v; P "GRID-SIZE-Y sliders, or decrease the "
* k% ~( P% j& @) l "number of cars by lowering the NUMBER slider.\n"3 q8 O4 v# y1 k5 s- m
"The setup has stopped.")4 l9 |6 F( `6 h2 e/ B, K
stop
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' [. h' _/ [! E1 u+ o ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ U$ t2 z& y8 ]) A7 f crt num-cars
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setup-cars
( a% z( \/ N! r( N, j# w# e/ X1 j- s set-car-color: g0 R# M: D) O- U
record-data F! M! q* A; x) x2 U4 \3 _3 E
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;; give the turtles an initial speed/ Z% `' ^1 ?. t; U
ask turtles [ set-car-speed ], u$ V- @ A' Y5 c% [& U
7 T0 D( U5 X5 j P+ ^ reset-ticks
$ M+ k: ^( a0 n/ ?" z% d$ L6 rend
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;; Initialize the global variables to appropriate values
1 |1 t$ X: F! dto setup-globals
# d* \& D7 O+ r5 L. T- l set current-light nobody ;; just for now, since there are no lights yet- V1 S y& l; u% x$ E
set phase 0
; c8 U& y- y* ~: e) k set num-cars-stopped 08 J" j" h# ~6 `5 x# ~) Y% R
set grid-x-inc world-width / grid-size-x1 G1 I( V! P! X
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 boundary9 a, \# _3 C3 G3 V6 A! H
set acceleration 0.0999 C- V7 d; ] H4 B8 r: f" s* I
end4 g, T, g1 y0 a! ~% T6 u& ]
3 s8 B5 B8 T( \9 t6 L. d6 w;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* v: j8 P- F1 r% n; U0 s" f; [3 \;; and initialize the traffic lights to one setting
3 Z- v; ^4 n [ a( \' z, @) E8 ^& bto setup-patches: x. s+ S5 e' u% J
;; initialize the patch-owned variables and color the patches to a base-color$ T, [, s1 K$ B: D- q
ask patches% e0 S0 ]3 l5 |' p
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+ w" C6 e7 j: q$ t c2 l: o set intersection? false; D/ m* }" Q, [2 P4 c
set auto? false0 f& Y3 s6 @1 B. V# N9 [
set green-light-up? true
' Y, c) p7 g, K set my-row -1
4 ~2 {+ g' `! T: H% g9 f set my-column -1' a4 ?" b' S7 i" m% \- _
set my-phase -1) V& }5 b6 y, j7 l5 B
set pcolor brown + 3. E9 k/ T+ n& C5 \
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;; initialize the global variables that hold patch agentsets6 D0 D% ?/ p, ]: n8 p: [
set roads patches with
0 L# @( E2 r* ]/ Q! s' Q! g& V2 L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) E H! c d% Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 Y( W! s; |8 i' d9 C$ i
set intersections roads with
/ b) E! O7 y3 r5 `0 ]/ x [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
. S* | ^9 D4 o( m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
& }* |- H! f$ o9 _ setup-intersections
" u1 O8 Q5 V# \" qend O5 Y& ?- r& ]8 a( m$ d
其中定义道路的句子,如下所示,是什么意思啊?
2 X; e& v. w* d- G( _7 j5 v set roads patches with
7 t& I' M5 K3 j. a8 s [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 e1 y; J( i. u3 P. s8 E) R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; G. O6 t, L$ s+ z6 w1 x) S
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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