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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。
5 X3 G5 [' p. P, u( H! K8 M$ [: rnetlogo自带的social science--traffic grid这一例子当中, K) Q; E& u, U. f& x0 q0 o
globals4 E" I# r, ~( T8 G
[4 l" a6 C5 x" }
grid-x-inc ;; the amount of patches in between two roads in the x direction3 x, b, P' U- C8 C5 }
grid-y-inc ;; the amount of patches in between two roads in the y direction
( n% `( e3 |# M c# K8 l( s acceleration ;; the constant that controls how much a car speeds up or slows down by if& Q0 b3 A0 _: a
;; it is to accelerate or decelerate5 i" c2 m1 K4 A& z4 e) r5 u4 L
phase ;; keeps track of the phase
( }) f. D, O v E9 Y4 y* [( q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 M. G" K8 d+ V current-light ;; the currently selected light
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;; patch agentsets
9 _4 |/ D2 I1 Z intersections ;; agentset containing the patches that are intersections
" Q% ^& R, S- F) x roads ;; agentset containing the patches that are roads
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]0 l' X& k0 {" ` `turtles-own
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' C. F) z. i. L' f2 O. m speed ;; the speed of the turtle; W; i7 d+ J& O$ h& @9 `' a+ K
up-car? ;; true if the turtle moves downwards and false if it moves to the right
; _. [# o2 \/ K9 _* c+ R& C4 ` wait-time ;; the amount of time since the last time a turtle has moved t$ _! M$ n4 q2 P. @
]
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads: e: m0 [3 S- M, T% H
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
y( ^3 L0 @1 p; x4 o6 W ;; false for a non-intersection patches. s2 l8 f+ `6 V: D
my-row ;; the row of the intersection counting from the upper left corner of the: N8 C: V8 b" Q) p
;; world. -1 for non-intersection patches.
4 C" k8 G" G% Y5 \% s) q, _+ x my-column ;; the column of the intersection counting from the upper left corner of the
# Y v2 } u+ i, [ A5 C0 N ;; world. -1 for non-intersection patches.( Q( X0 Z u; `: D/ |6 \
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( `' Y$ c2 A. b0 C8 L$ F auto? ;; whether or not this intersection will switch automatically.1 b7 q" X6 x* N. h" `
;; false for non-intersection patches.
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! I( i! u! \: Q) I! h- L;;;;;;;;;;;;;;;;;;;;;;
! u9 o: v n' r$ A# _;; Setup Procedures ;;+ x- l9 C: k% D- h7 z/ N- ?) L
;;;;;;;;;;;;;;;;;;;;;;. S1 k L: X- q6 r' y
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;; Initialize the display by giving the global and patch variables initial values.. H+ n( l& C% D \0 W
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 S; s f6 J2 X) p- };; be created per road patch. Set up the plots.% a6 a6 o0 Q0 o5 _
to setup
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+ a% v7 W% E3 c/ P, Q# M( j; x setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
3 O6 C2 g9 j, m. R3 ^/ K setup-patches% w0 i* H% G# X
make-current one-of intersections4 z/ z$ t1 |5 X
label-current& f) p3 a$ [8 y$ W4 c! v/ R2 p
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set-default-shape turtles "car"& T% e, S o `
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if (num-cars > count roads)
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. g/ J4 V" A$ _; T/ R3 q1 [ user-message (word "There are too many cars for the amount of ": c, @0 W( G; O4 A0 `: z
"road. Either increase the amount of roads "2 k( r; T+ ]+ I6 i! ?8 C
"by increasing the GRID-SIZE-X or "8 y0 L+ E' D0 {& r/ E# f' S
"GRID-SIZE-Y sliders, or decrease the "
+ B9 }+ g, I" s/ w8 W; ?7 X: [* |! U "number of cars by lowering the NUMBER slider.\n", B. M; x) M, f' x) @3 L3 p6 c1 v; _
"The setup has stopped.")% f" x6 Q, X- q9 }: g
stop
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1 }9 y% r8 A# Q. a ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ U1 [3 N5 ^7 g2 k& D6 z3 L crt num-cars
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setup-cars) l. E" [1 \9 X5 Y
set-car-color( H, a" G7 D, _0 C
record-data9 G5 G* ^/ o) d/ z
]
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;; give the turtles an initial speed
% k/ h7 j o: ~/ [5 V ask turtles [ set-car-speed ]. h' [* i' E, |
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reset-ticks
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;; Initialize the global variables to appropriate values1 _+ j2 w, m3 s- F( p' Z4 s. p
to setup-globals3 ~% p, g* E7 S& k2 D& Y
set current-light nobody ;; just for now, since there are no lights yet$ W B0 M; n2 u/ |1 V: T
set phase 0
2 x2 r! X9 R( T. N0 A9 m. H1 }6 | set num-cars-stopped 05 Z6 U9 S5 a9 I: p6 I3 g j
set grid-x-inc world-width / grid-size-x
0 V3 d5 {2 o# r2 h$ M4 P set grid-y-inc world-height / grid-size-y
8 z% w m! `- S2 f) \
% P7 \! N/ w$ K ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: T) ~) v+ F4 Q! F
set acceleration 0.099( p6 L* S1 O$ f# j/ H" N/ j7 `
end: F; N' t# O6 j* x; J' x: o
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 k9 I; m9 Z/ S- `0 b
;; and initialize the traffic lights to one setting
( T. ?$ J7 @0 G& Oto setup-patches
* R- Q: }( N* G1 C% A; x ;; initialize the patch-owned variables and color the patches to a base-color
, [% j9 O/ R, t3 e U9 B! [ ask patches
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set intersection? false
, u6 f) R# k% | f set auto? false
' u; G. ?8 c3 f9 | set green-light-up? true
( m: C3 e( _4 |1 w7 x [) _ set my-row -1, G R& }9 E# n/ }, U
set my-column -1 v+ X7 l: j7 Z0 b8 R1 A
set my-phase -18 O2 T8 u( t: d$ R
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets1 H# i% a0 t8 y
set roads patches with
# l$ s1 Y/ b9 t" [- E9 h, D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 K9 G" C, b+ y* |" V) _, _2 v5 f9 a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 A6 y* C# U' p+ p$ c
set intersections roads with
" k2 s' b0 h0 D3 m# a [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ o) U" K9 a$ Y7 f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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$ L- _" f' U5 [6 T8 I% x ask roads [ set pcolor white ]
2 h! C; ]: z$ U8 ~, F setup-intersections
2 c1 F3 X! S: ]- O& j, B; f5 |end ` x5 w( x/ ^0 p) o
其中定义道路的句子,如下所示,是什么意思啊?( t' f, \; b0 D+ w+ Y2 J
set roads patches with6 b% i( B- J; B$ \9 Q9 b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- X4 S& D8 @+ I5 O X (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( N3 ~; c" X# N) d1 v& q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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