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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。
3 Y# ~% X( g% Qnetlogo自带的social science--traffic grid这一例子当中,! q9 C* z! y9 m: N# w2 T7 M5 C
globals" i% k4 E' |2 R4 u3 ?- N
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" g: e' }2 y* o9 k9 Z grid-x-inc ;; the amount of patches in between two roads in the x direction
5 w( l6 L- k. P O, Q2 }3 ? grid-y-inc ;; the amount of patches in between two roads in the y direction' o' I/ \' S6 |1 @' @
acceleration ;; the constant that controls how much a car speeds up or slows down by if
- g' \3 B. G/ z0 T) X3 k- G ;; it is to accelerate or decelerate/ x8 e# ]" j$ P! G- k& r
phase ;; keeps track of the phase6 m% w; M" i' s4 f
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. J+ W; |; P' R/ y' n3 @
current-light ;; the currently selected light
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9 e6 t; G6 ]$ E; _; W ;; patch agentsets6 v8 u: S9 ~1 w% X0 H
intersections ;; agentset containing the patches that are intersections
1 C, b4 p0 s: r) R4 _: n9 i roads ;; agentset containing the patches that are roads' X% t( T P3 n+ E+ v
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turtles-own
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speed ;; the speed of the turtle
A# t3 w3 @/ y1 P up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 m6 ^! S' Y1 R o wait-time ;; the amount of time since the last time a turtle has moved: m# s: w) A, W3 z. [8 ?+ q
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! }/ ^% h: Y. n, I {! |patches-own0 R- g* Z7 J& e( t
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; W3 \3 Y/ }0 q0 ~# T- s intersection? ;; true if the patch is at the intersection of two roads
K8 X4 S9 ^. R- ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. d+ C, m/ p, e- Z e ;; false for a non-intersection patches.
; e# {. }$ q ~- L: E$ ?* E; z my-row ;; the row of the intersection counting from the upper left corner of the% w0 W/ ~( ]& o$ M/ c
;; world. -1 for non-intersection patches.
+ M9 z U! b* c' L' J. e my-column ;; the column of the intersection counting from the upper left corner of the# O) ^- u/ T# m& Z" C
;; world. -1 for non-intersection patches.
7 J/ H+ C+ x$ T" J" i" y8 E my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 [" j, G. c5 d auto? ;; whether or not this intersection will switch automatically.
f1 G, s% s8 U# F2 J) I% i ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
# b3 C7 e- O4 u$ Q;; Setup Procedures ;;: G: T. D7 \0 H2 j
;;;;;;;;;;;;;;;;;;;;;;+ r. ^6 \ Z! }: E, L) r
* s0 x/ d. R3 n F9 };; Initialize the display by giving the global and patch variables initial values.
! [+ m: U$ T% o4 G1 u6 {/ g5 b;; Create num-cars of turtles if there are enough road patches for one turtle to
1 ~% I2 d- }4 ]8 j2 Q2 u" E;; be created per road patch. Set up the plots.
& S3 j, Y7 t$ p. Uto setup" h7 I1 k8 C/ F8 E, ~6 ?
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setup-globals' X/ C% K) e# z2 H9 ~
3 r+ Z7 Q- S6 L( h ;; First we ask the patches to draw themselves and set up a few variables
" x+ p# m6 p. z; |# e, R8 G6 @ setup-patches, G) W. ^9 y: g. T+ `5 C' N
make-current one-of intersections. J5 R% }- u0 ^, g' ~
label-current
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set-default-shape turtles "car"+ J$ T# q! m( s5 j4 M; `
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if (num-cars > count roads)$ J ?5 S: J2 h1 a4 E5 V; _; {1 B
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user-message (word "There are too many cars for the amount of "
1 m; B; m7 H9 [, O2 h "road. Either increase the amount of roads "! x1 G+ r! Z, \3 D
"by increasing the GRID-SIZE-X or "8 K. l0 C" u) O/ v3 E# l
"GRID-SIZE-Y sliders, or decrease the "
+ Y4 B* T F( H/ C7 C7 C* P0 H "number of cars by lowering the NUMBER slider.\n"
, F* f: k8 H+ |9 V "The setup has stopped.")4 W+ m0 M; I/ K f0 O
stop
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c9 L, O! }# Q* U ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 T9 t& z' N' f" A/ m. J, h2 E crt num-cars
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setup-cars
3 m8 n p, I" P$ s3 q x8 } set-car-color1 \2 `- r/ W- ] B- T
record-data- c; \, p: u0 w8 A
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, E( ]6 d& c. W+ d+ J& w ;; give the turtles an initial speed
7 j% `6 L6 x" \8 `0 l* n: J ask turtles [ set-car-speed ]
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reset-ticks' z* r1 W7 W1 N4 G8 q+ j7 Q% i3 e# y
end
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- c& R+ S' [, `% r6 s* V* f! z$ N: s;; Initialize the global variables to appropriate values/ B O' q8 J$ e$ z+ V
to setup-globals
3 A3 e+ J* {$ L: E6 I7 _$ ^/ y- N set current-light nobody ;; just for now, since there are no lights yet
5 r5 [7 y: _. d# h" U* ^ set phase 0
: e% X7 U6 E% i' g8 t set num-cars-stopped 0$ I$ I% G2 D- D8 g' S5 P! g
set grid-x-inc world-width / grid-size-x# J( M/ P" c; h3 p) T# @
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 boundary; Q9 `$ _( ? a% ^, ?
set acceleration 0.0997 F' n- _2 ^* l: G' ^+ R5 t
end. ~& U/ e! q; ^- N2 L
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) k/ y% Z* O5 | u+ d9 ];; and initialize the traffic lights to one setting
, H9 y: g6 m: _+ {( jto setup-patches+ x8 j8 h% H' J: d
;; initialize the patch-owned variables and color the patches to a base-color# H- E# u! U4 Y0 ~
ask patches, s5 n; O: W' h6 S
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set intersection? false# M7 K: y3 K6 C7 _4 [; ^1 B
set auto? false' \9 ~5 o$ D% {# c! Y
set green-light-up? true" e1 I8 H, G- s8 ]
set my-row -1! W& w3 `! d" x5 V
set my-column -1
0 E& u0 R4 b6 D$ W set my-phase -1
3 y3 i% H: S# w$ ]! k% H set pcolor brown + 3
3 D0 K5 X' Q5 c6 g6 B4 M0 ?0 ] ]
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9 L/ ~9 l* @5 U" X1 U b, d5 V ;; initialize the global variables that hold patch agentsets
) a$ m& L4 Z5 y* B2 h set roads patches with
d% r7 v7 |" M0 w. N5 F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" L4 M# E. |/ a2 Z5 Q* K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; N9 _1 D: u# d+ V3 J. _( I
set intersections roads with0 G( a/ [( _% y' ]% C+ \) s8 D" u, R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* H( l5 z: K8 S (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 }' `9 L4 Y& p) E
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ask roads [ set pcolor white ]
6 h, h+ Z4 B% ]. M) H8 u+ i/ ~ setup-intersections+ e' k1 q, N+ O
end0 |5 ~* V8 ]+ n
其中定义道路的句子,如下所示,是什么意思啊?7 h6 E; x h( y9 V5 F# q- P
set roads patches with$ ^, s) [7 O' |: x- F1 d0 D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# k# {; x" q: ~( d' o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ z% d% X6 T& @% w8 [1 u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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