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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 o* \" p y! v( Q5 A0 S) o
netlogo自带的social science--traffic grid这一例子当中,5 D. i3 w7 l Y. m9 ~' ~
globals9 O1 H3 c$ C/ |" {# x
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0 p% I& v2 c" C, z grid-x-inc ;; the amount of patches in between two roads in the x direction- o, p U5 E; x; j
grid-y-inc ;; the amount of patches in between two roads in the y direction
8 d% S2 ?1 z7 S2 S! ~' q* B9 { acceleration ;; the constant that controls how much a car speeds up or slows down by if. f: P% q; `: w
;; it is to accelerate or decelerate/ `) U/ e0 ?! N% D' p$ a
phase ;; keeps track of the phase
; ?* d. q! O. `7 ~5 x num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. F: |% ?8 q6 e current-light ;; the currently selected light8 d0 D. t. g4 L5 W) I; X. c
3 g3 O6 r* v% H. l0 C# R" K8 z ;; patch agentsets
& _3 X/ G; [. y: c* P" J# k8 Z" a intersections ;; agentset containing the patches that are intersections% \5 j4 M7 \8 a5 ?# q+ {4 W
roads ;; agentset containing the patches that are roads8 R; K& h' s8 X; d8 u" V' C/ M
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turtles-own
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6 }. A" ~* a5 A7 d% [7 u: s/ H9 V speed ;; the speed of the turtle) K% k# G6 F- d) O
up-car? ;; true if the turtle moves downwards and false if it moves to the right+ ?7 H4 J R5 U9 ]' l u0 U* {! n5 A
wait-time ;; the amount of time since the last time a turtle has moved; v# P2 g8 ?$ r3 O
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: E! e& @$ d/ c& xpatches-own# N2 M( d! ^' K7 z
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intersection? ;; true if the patch is at the intersection of two roads
2 K" S* f* A- D0 {# Z& H+ T green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 t6 | ~+ H* l9 P# b ;; false for a non-intersection patches.( E9 C% f5 m: J/ p# J( A2 `
my-row ;; the row of the intersection counting from the upper left corner of the- t3 u" T& B5 j
;; world. -1 for non-intersection patches.
8 n/ w- E k* d' N% g+ I my-column ;; the column of the intersection counting from the upper left corner of the
0 p1 P t. X r9 H ;; world. -1 for non-intersection patches./ j& n L( n! s4 F! E8 p- e& i
my-phase ;; the phase for the intersection. -1 for non-intersection patches.! E( b7 i" J1 V1 J- ~% p
auto? ;; whether or not this intersection will switch automatically. O1 P3 o9 Q) `& o/ B
;; false for non-intersection patches.& A% k3 ~3 D3 k" q9 C$ q
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;;;;;;;;;;;;;;;;;;;;;;$ y# h# a5 l9 {+ f
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
) X {1 w3 r4 G8 t, d6 L) v;; Create num-cars of turtles if there are enough road patches for one turtle to
) A, L2 K; v1 v: Y9 A" M;; be created per road patch. Set up the plots.
& u' B, {7 z' X; Qto setup
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+ u# @ p( }8 R) E% D8 e setup-globals+ n8 g) x2 H. U3 Z, v y
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;; First we ask the patches to draw themselves and set up a few variables# G* K% T$ q: X5 [, s
setup-patches
* D% `9 ^: l4 d' u5 L4 N make-current one-of intersections3 V1 X1 h7 c! [( [1 q" U; ^
label-current, t3 o( l9 }5 u9 G
( _) ^% ], l0 ]# k/ Q/ i set-default-shape turtles "car"# y# K2 D" T9 _: u, s* O) \# _0 B
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ". M4 }6 T$ k4 {
"road. Either increase the amount of roads "
1 Z, W9 B8 J& j* v5 `: n0 u3 D "by increasing the GRID-SIZE-X or "
q7 n, r7 ~3 K, ~8 ~. v( e- B "GRID-SIZE-Y sliders, or decrease the "
4 m" P6 D6 Y* f$ d* p: Y4 E "number of cars by lowering the NUMBER slider.\n"5 |7 N) t" O: ~+ i& C
"The setup has stopped.")
( t z0 H5 w/ A/ I% ] stop
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9 E; l) Y3 @5 w; {3 ~" r ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! p9 v/ z; S9 d' T
crt num-cars
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6 n' {0 u0 {6 i4 ] setup-cars4 M( b# X9 }3 U) N3 h( H
set-car-color
/ x7 V6 G0 Q3 ] \8 p+ _ record-data1 e6 ~9 X6 G# p. P3 ?/ T+ C9 E
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;; give the turtles an initial speed/ K$ c7 h4 a% F( e
ask turtles [ set-car-speed ]
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) j& P( d* Q% a* S reset-ticks
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. B4 \; {: v+ w' @3 g6 c;; Initialize the global variables to appropriate values
% l Y. |+ h% c) [; R4 D( Lto setup-globals
" {5 p8 \( E/ f7 v/ s) s8 E4 [ set current-light nobody ;; just for now, since there are no lights yet
* u! |, x+ P' Y/ V1 t" T set phase 0
6 X" l, C1 j7 v9 M, C# p set num-cars-stopped 0
& r$ l3 j; u' W9 T' ]+ z. X set grid-x-inc world-width / grid-size-x1 @& ^) @' d- ?, J7 c8 U( d6 h
set grid-y-inc world-height / grid-size-y
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7 i: e( M; e1 c/ j- U) K8 z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' ?% D" ]& i1 j# t- I
set acceleration 0.0998 I- `0 f( i9 `! p
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 h( d0 ?; B3 K# g* t- \, G
;; and initialize the traffic lights to one setting
9 j1 U1 |$ P2 lto setup-patches- q1 [3 ]/ K! L" J7 \( b. n: N
;; initialize the patch-owned variables and color the patches to a base-color8 X4 C- c! q( U- V
ask patches
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set intersection? false
% g6 R$ W% R: |4 Q set auto? false7 v# U+ v0 x- k* [$ I0 ] R$ E( w
set green-light-up? true) o! ^& [7 `3 e1 M: f! ^
set my-row -13 p0 k' C: K) }2 J8 [! F8 z
set my-column -19 }& D& W: k( ]8 K6 W9 {; J$ d
set my-phase -1
; T' A1 t- \' J set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
9 X7 K; m& D) c& \; U: D set roads patches with2 b( J; S& S. L$ ^: W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 B* {' `1 H9 c |2 B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) n G: r3 C ^& I7 u r6 y) K2 _6 @ set intersections roads with
. l2 {: x/ p$ G0 I' {" R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: _& r) [, S; N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: F: W3 @) x6 k: Z/ _
* X+ k2 C" X4 X" ` ask roads [ set pcolor white ]+ [% ]: H' E1 x; ^# A5 h- q
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?8 W, K- v# ^ B$ ?' N3 S# m) k5 {
set roads patches with
* S9 ~3 w" ?4 ]( W: J$ w1 x- Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 z, [- V7 c0 i0 M; x% J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 V- s- {4 Y3 m% m$ x5 J: T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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