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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。
$ a7 ^+ L1 {- {- L3 Y Znetlogo自带的social science--traffic grid这一例子当中,
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" q: w8 M; ?0 k- q grid-x-inc ;; the amount of patches in between two roads in the x direction, L/ W& \# G% Q( X2 H
grid-y-inc ;; the amount of patches in between two roads in the y direction& U$ o j9 }2 J' {& [
acceleration ;; the constant that controls how much a car speeds up or slows down by if
( J) _! J, f7 v; d+ D% h) m ;; it is to accelerate or decelerate
0 F" v8 |9 G- U1 ]2 V& P phase ;; keeps track of the phase' X& T% U U, j' a, c; ~
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* ~- B9 h& I e' w3 u$ p current-light ;; the currently selected light8 g: [: C i0 R7 P r) p4 x
8 V6 R! U5 W- v* n$ H! b N& T ;; patch agentsets5 e; e) w7 s! A- f8 O8 O g. A
intersections ;; agentset containing the patches that are intersections! G, {3 X4 |# @1 X7 I, }
roads ;; agentset containing the patches that are roads
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. ]: _4 @4 R" f2 J4 s# X: `0 lturtles-own
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speed ;; the speed of the turtle
, ?# v$ G; q, D/ V' d3 }. U up-car? ;; true if the turtle moves downwards and false if it moves to the right
Z- t1 X m* x4 T0 O0 f" f+ F wait-time ;; the amount of time since the last time a turtle has moved3 i& r2 d) x o/ [; y2 S
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patches-own4 K" f2 { J# b9 }, q
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intersection? ;; true if the patch is at the intersection of two roads7 D* Q: z! ^% @7 U! ?
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
5 G; d5 I0 d+ T( f0 s ;; false for a non-intersection patches., |# e" `- J( p) W* F
my-row ;; the row of the intersection counting from the upper left corner of the9 r/ o; x y. ~9 C( {
;; world. -1 for non-intersection patches.
! |, ~( r- v; \( [! S my-column ;; the column of the intersection counting from the upper left corner of the
$ }( O2 N& ]# @ ;; world. -1 for non-intersection patches.
D( n. {8 P! l my-phase ;; the phase for the intersection. -1 for non-intersection patches.
" c# n) c! q' g auto? ;; whether or not this intersection will switch automatically.
7 ~& n* X; D$ H# g5 ]% n ;; false for non-intersection patches.. z! M! l/ w' d$ e7 i4 G
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;;;;;;;;;;;;;;;;;;;;;;
4 p$ L9 @# n8 I4 l;; Setup Procedures ;;
( G7 n* I+ Z4 g. O. W3 z;;;;;;;;;;;;;;;;;;;;;;
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& }2 A+ K7 p' g( w;; Initialize the display by giving the global and patch variables initial values.
( U% ]6 F \% y2 y, t, M; W;; Create num-cars of turtles if there are enough road patches for one turtle to: {3 F0 G- y- `* Q( s: b
;; be created per road patch. Set up the plots.
9 u6 }5 d; e& `. O7 qto setup2 }' m4 U+ F* X" |3 r6 t2 w
ca
2 L+ O& n9 w& e0 t6 V; D3 Z setup-globals
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;; First we ask the patches to draw themselves and set up a few variables3 ~* ~+ n4 n# e, H* k# s6 j* o
setup-patches
9 l0 |, n# l2 [3 S+ k make-current one-of intersections
; H4 x# f5 M/ ]$ @. b' m label-current4 n) h7 ?3 k/ S' u
9 ?/ W( P9 X+ ]; S7 g8 C set-default-shape turtles "car"" d# V, d' Y8 Z' [* m9 K% ^
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if (num-cars > count roads); B: _2 u4 R+ ^* T+ E' c
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% }" C, o& F6 \ user-message (word "There are too many cars for the amount of "8 ]/ n) h2 {8 R: S6 r. S
"road. Either increase the amount of roads "9 _1 _2 Y4 ?: {) [
"by increasing the GRID-SIZE-X or "
. Y& I% V% ]0 a) q+ o8 O "GRID-SIZE-Y sliders, or decrease the "
+ g4 Z; V1 O& m9 `# U "number of cars by lowering the NUMBER slider.\n"
' D5 B0 f* v8 k+ I "The setup has stopped.")
. M2 H: U" G* G4 G8 t stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, N- u1 k) g; A7 @8 a$ S
crt num-cars$ I+ @- }$ |8 o1 ?3 a) d* ]! A
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setup-cars
3 q! G2 a3 ]( V2 {: R7 E set-car-color
( P8 T1 f4 e8 x$ X! ? record-data$ ^4 Z; E' d7 n0 f' q2 _+ h
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. f+ ^8 N' Z2 m, e5 y! M; U ;; give the turtles an initial speed
! F. ^ w7 a' g% I$ x ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values
5 |; @1 X+ t9 Z, T+ y$ Y; L. cto setup-globals" B& P$ h0 m+ C) q) e8 U
set current-light nobody ;; just for now, since there are no lights yet Z, r, \* N/ o* q* l4 c& S; o% S4 F
set phase 0' m2 a) t/ |, t4 r& A* r7 Q
set num-cars-stopped 0
9 Q2 `, t+ j K" e set grid-x-inc world-width / grid-size-x d: O% F0 h q6 c
set grid-y-inc world-height / grid-size-y/ n& d9 R- J4 L- [& l* R
+ w( T' L7 Z2 W3 K% i8 H9 u ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
]( I/ r9 m; B( s set acceleration 0.099/ @2 H3 T- @" B7 X
end% G+ ?1 y+ E$ T
$ A" ^4 E; O2 ^& W$ M# h0 I/ j5 I& K;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) O3 w3 R6 G: Q( u# g# X4 c;; and initialize the traffic lights to one setting! s) t( `" l$ J; `4 ?! ?- ^, L& H
to setup-patches
3 Y/ {7 f9 h2 n9 Q: q ;; initialize the patch-owned variables and color the patches to a base-color& k7 d4 h$ {# C S3 U# N- w
ask patches- n, A9 U7 q; J7 w% q+ [5 o
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- `2 V4 a0 A$ T! D# s0 {* l0 R7 W set intersection? false
( T( `5 y6 ^& @8 @. X5 {6 Q2 c2 t, i set auto? false3 I! m V5 T, k$ s2 `8 N
set green-light-up? true
$ z) I, h n: ^3 a set my-row -1' r% G: |/ L0 F, L1 E
set my-column -1: K, B, t4 [* I5 l+ G: X0 \
set my-phase -1
F1 S# k- @/ B: W o set pcolor brown + 36 j) N) ]) `0 L, T+ O
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;; initialize the global variables that hold patch agentsets
: r% ] }8 m( F, {& P* b: f- { set roads patches with
5 Q8 N; K" v( C, B4 F! E+ ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& r9 H. P( `' u' E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" X7 p9 ~0 ?6 `# E! b
set intersections roads with* Z5 E D. d2 f" q0 }* A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, A' ~8 H' G/ s+ u, i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: w: }' |6 t; B( \: a1 K- P2 T ask roads [ set pcolor white ]
# K2 g& a1 P8 l% E f setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
* O7 |$ o9 P* _6 V$ ?7 y set roads patches with8 L1 ^& h- e$ U& B# D }* R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& F) v+ t3 x/ z( A! K* q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& z: q. A# m6 Z% W" v, b
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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