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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。( l! S5 [1 S1 h: E
netlogo自带的social science--traffic grid这一例子当中,, L/ E4 Z) H$ ?: [& g" ~
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
) W8 \, A2 S. W' [: l; U1 R grid-y-inc ;; the amount of patches in between two roads in the y direction$ R+ a' v/ D! w" D; o3 p/ n, e
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 b$ z- ]2 Z' a; u0 q! b ;; it is to accelerate or decelerate1 M1 F" f3 ]* N/ R5 g$ s
phase ;; keeps track of the phase
" {& L' ]0 O1 k$ L; E a. t num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
6 L/ S9 Z/ x N' A current-light ;; the currently selected light9 l# [5 z2 W5 k
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;; patch agentsets. B" P( l7 ` e4 J a$ l- T
intersections ;; agentset containing the patches that are intersections% J# T* c0 V1 `! Y& q* X
roads ;; agentset containing the patches that are roads
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6 v% w8 w8 f. D& Q$ T" T; {. O- Fturtles-own
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' H$ C0 D4 ~0 i$ H! ? speed ;; the speed of the turtle* s' H4 r% T! f: E' {
up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 v8 q6 G# J; K wait-time ;; the amount of time since the last time a turtle has moved: I n" u' Z7 F: ^( ~0 F8 c6 P) K
]3 N5 ], U4 l3 L/ z }
; O, p/ v/ [3 \patches-own/ k: ]! C5 y5 W( `
[
4 }7 x5 x7 v) C0 b* ^2 M: V intersection? ;; true if the patch is at the intersection of two roads
1 V: _6 v9 Y; o7 @; k8 }/ H green-light-up? ;; true if the green light is above the intersection. otherwise, false.; k" E) e! ]4 g6 W# J2 t
;; false for a non-intersection patches.5 I0 C. Y% f+ r6 P: E
my-row ;; the row of the intersection counting from the upper left corner of the
% ~( ?4 {5 N& v% K: v ;; world. -1 for non-intersection patches.$ p9 m' _9 }* s7 m& [0 e( J
my-column ;; the column of the intersection counting from the upper left corner of the
' _) I4 {: C% G. t8 B! W. A ;; world. -1 for non-intersection patches.' Z' F0 D. r6 i% B
my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ [1 v5 u, Z: ]' b; d" P" n
auto? ;; whether or not this intersection will switch automatically.( C8 K, O- M* x- B/ L
;; false for non-intersection patches.
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& w! z7 l, d; C) T5 G+ D;;;;;;;;;;;;;;;;;;;;;;
' j) M) B: U1 \' q/ M& S6 D) W;; Setup Procedures ;;" i h7 Z% @ [3 ~& E" U; N3 }7 W4 L0 M5 f
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.& T% R W2 S* a! c5 Q8 E6 ]
;; Create num-cars of turtles if there are enough road patches for one turtle to' @! C7 b) F) d0 |8 i' W
;; be created per road patch. Set up the plots.
: Q6 w2 |8 Y' T+ A8 R( _to setup Q8 {1 x: i$ e
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setup-globals, i7 k8 r- L) _) ]; _% e/ S
! j+ d7 O8 H% s. W, [ ;; First we ask the patches to draw themselves and set up a few variables7 y, |8 ]: j$ C2 ^' x* O
setup-patches
" r2 C) t0 x9 w make-current one-of intersections5 n4 _/ j5 K' k; U3 l
label-current
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& Q5 [& d# o8 u set-default-shape turtles "car"
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/ m8 s* F! f* h, w if (num-cars > count roads)" m7 z$ u' _. F7 U* u' d8 v* N
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user-message (word "There are too many cars for the amount of "
+ P* @$ Z5 d: V' k/ U+ M) n3 y "road. Either increase the amount of roads "! d ~& ]. K3 ]/ N/ B( N% S1 G7 v
"by increasing the GRID-SIZE-X or "# c! t# J( m! C3 d, f: u
"GRID-SIZE-Y sliders, or decrease the "' v7 R. w9 U" _/ Z) q
"number of cars by lowering the NUMBER slider.\n"% [1 @( M* R0 g2 \) G/ E
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 l9 R. d6 f$ x3 K. f0 O
crt num-cars7 h% ~+ x4 P) m' [- n: f. |5 f( p c
[
% }- y6 S- D8 S, @; N- t9 ]* v setup-cars
* x, F: u5 l3 @ set-car-color
3 P# ]7 ]( o! c5 i1 p( U record-data
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1 _4 M" ~6 z4 y ;; give the turtles an initial speed
: q1 [8 ?& n1 x0 v2 e ask turtles [ set-car-speed ] ?, H% {8 Y+ K( ]
* {. T8 `$ E* K# R% T7 B$ z reset-ticks. n, j; J4 X( X
end
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+ o5 t# W* v7 n" W D6 q;; Initialize the global variables to appropriate values [3 {- w( x8 B3 F; T
to setup-globals
* d Y7 Y& [$ R. D1 g2 g set current-light nobody ;; just for now, since there are no lights yet
; I6 z# a1 ?' |8 p set phase 0
3 A: S) _5 `+ B7 W set num-cars-stopped 08 z7 F3 a8 f+ c) v: q4 E' Z
set grid-x-inc world-width / grid-size-x
5 Z7 p d- }& G3 p% Z2 b7 w set grid-y-inc world-height / grid-size-y
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7 u5 o. l$ k g# e' w ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary1 s/ Z! R4 L) `7 N2 n
set acceleration 0.099# ], [% b8 A, w
end
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* t1 M+ b6 J1 N1 I;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
. i7 n I9 t& h0 W3 a! p6 l( k& a+ S;; and initialize the traffic lights to one setting. U# X1 }: a6 t. g
to setup-patches
! i0 @1 x7 I N* U4 ? ;; initialize the patch-owned variables and color the patches to a base-color; q) E: s/ D# J$ i$ u a
ask patches
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set intersection? false
4 {/ m5 o% {& ^ set auto? false/ k% a) y' a% M7 q; J6 `
set green-light-up? true8 f7 x3 W# {/ g6 s4 l
set my-row -1$ L1 B( s) \) A6 z7 l7 P' O
set my-column -1
8 P! X8 G# A/ R3 [/ a1 {% ^5 ^- Z set my-phase -1
! K. X1 T1 L5 ]. A2 m% D set pcolor brown + 3
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7 b d/ T5 X9 i, _# N ;; initialize the global variables that hold patch agentsets: m! _4 |. B% r
set roads patches with
9 D# _) h6 k% K: D _4 g( x [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" E( v' }4 ]9 ~6 P, f3 K1 q% {% c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' ^ n/ M- x/ z4 q. D+ t1 p set intersections roads with g; W" h) t1 \: P- q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
1 a: ]5 s h. i6 R' l# Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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# x; O L v4 { ask roads [ set pcolor white ]& h, h0 s0 @% B6 t
setup-intersections2 |8 B7 ~+ k9 s: Y2 F0 j3 f$ q
end
3 Z3 Q6 G. Z, V4 Y其中定义道路的句子,如下所示,是什么意思啊?
. e$ ?9 D% N* V8 e set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 X! f8 G1 E: @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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