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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。& ]$ @$ o0 w. {$ W2 r
netlogo自带的social science--traffic grid这一例子当中,
: D7 Q) _: ~ z1 Yglobals3 N- B+ M8 ~. c' ]/ L/ ~9 u' X
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grid-x-inc ;; the amount of patches in between two roads in the x direction( l3 P$ @# k' i) a
grid-y-inc ;; the amount of patches in between two roads in the y direction
. J3 I( V9 ]. s b2 w acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 D0 J: v0 G2 @+ B( B4 a ;; it is to accelerate or decelerate# ^1 A" M# d6 l: t( g% I
phase ;; keeps track of the phase8 x' {5 ~0 N+ f' k9 |
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 Q# T1 t. l4 U: ]( Q
current-light ;; the currently selected light
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: \5 ]: D @+ S; K6 @2 X) u ;; patch agentsets u c8 O& Q+ B% E: s
intersections ;; agentset containing the patches that are intersections
" l( Z$ m6 b+ z3 Q5 B7 R roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
3 j0 ^% l$ @. g% F up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 E, |! E; K. C" Q6 h& S1 r wait-time ;; the amount of time since the last time a turtle has moved
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$ D1 ~0 `# I6 p% Z+ A7 w2 b, ipatches-own
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intersection? ;; true if the patch is at the intersection of two roads$ {7 l U8 V! X9 N1 [& C& i1 ^
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
% o4 `" g7 R0 a) E1 M, N3 q ;; false for a non-intersection patches.
; u7 M# H! o* u+ c+ l* S2 m my-row ;; the row of the intersection counting from the upper left corner of the& P3 C0 B1 b1 j
;; world. -1 for non-intersection patches. Q- n: ?0 i' i o4 D' V8 n
my-column ;; the column of the intersection counting from the upper left corner of the
e2 r& A' J, v6 |. g ;; world. -1 for non-intersection patches.& t' S) h- {9 t- _
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 |6 V9 k. h* w4 B# D# j4 i& t auto? ;; whether or not this intersection will switch automatically.
0 G5 f9 I7 T3 @ ;; false for non-intersection patches., z7 Y9 y. L0 J3 p6 C" V
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: D [% E" N& b;;;;;;;;;;;;;;;;;;;;;;
9 {, A9 ?9 W' q6 X( J4 G+ I. o;; Setup Procedures ;;5 q) k0 p5 v5 U/ Q7 _; T
;;;;;;;;;;;;;;;;;;;;;;
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* ^9 {4 |5 s$ T: D;; Initialize the display by giving the global and patch variables initial values.4 [; _% \) R, X6 p* \
;; Create num-cars of turtles if there are enough road patches for one turtle to) g9 m* [# |! b5 H9 X4 d
;; be created per road patch. Set up the plots.
) K- j1 h- W8 ]% ?- A) R' u4 Cto setup! X% P! O& _; x$ ~* A5 [( x
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables4 V! x) w7 h3 {" h
setup-patches1 c; m9 B3 k; H; ~% l( B
make-current one-of intersections
1 X* V- }9 l p; c! t, x/ W label-current# g. y6 ^8 s; B: p5 X4 J
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set-default-shape turtles "car"* {0 n5 F3 c1 ]: |- K
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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 " r. E8 m5 F* Z9 V% [; F
"road. Either increase the amount of roads "- V# g; @ y0 C: K7 |7 b0 o
"by increasing the GRID-SIZE-X or "
" n* k6 P1 b4 Z. Q/ h; j( g "GRID-SIZE-Y sliders, or decrease the "" C$ D' K( P# Q+ x) b: k6 F
"number of cars by lowering the NUMBER slider.\n"
2 t$ G+ p* U* W" j7 ^4 A: `( T "The setup has stopped.")
0 d: b5 p! [+ W) ?+ t stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ f7 ^2 b0 s9 j3 }2 y
crt num-cars8 a( g7 x' C$ _- p; R0 D+ |
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setup-cars
3 S! G; l9 o4 v9 ` l& T set-car-color$ i+ z3 W4 c( \: i) {5 D
record-data
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T( {2 e, ^8 E, \3 ^ ;; give the turtles an initial speed
5 h, y; k) t7 w9 p$ Y' e4 B ask turtles [ set-car-speed ]
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reset-ticks: E% A3 {9 c7 |9 R( h4 ]
end0 I9 z8 Y0 _ L- C3 I; ~7 o
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
8 F' T! O T0 U U! Y; c7 W/ ~$ Y set phase 0- ?8 w" Q o3 \$ H6 r
set num-cars-stopped 0
2 r" l, Y' v4 f, N1 T9 H& \6 U set grid-x-inc world-width / grid-size-x) a& I+ Q1 w2 X8 a# |
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
* h3 J7 _8 `+ q) M4 T5 F set acceleration 0.099: C( }* u. }# k+ }) v6 Z# R) m/ ]
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
' @4 W- R5 m& t2 W/ A! D0 q;; and initialize the traffic lights to one setting
- v2 f6 M e. uto setup-patches
: |* i, D7 x' C) E" \' j" }0 ` ;; initialize the patch-owned variables and color the patches to a base-color: a" T" |8 E$ E3 b
ask patches
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3 }+ ^0 s5 D( S8 G; `+ u set intersection? false
8 q/ T* _+ E8 M- v4 K0 X) n set auto? false/ c7 s! O. v1 L* b2 t( ]4 Z
set green-light-up? true
+ Z0 G6 P4 K+ N/ N( l, X8 W set my-row -1: V: I+ o8 Q& J# m' Q9 l
set my-column -1
: T) F& J2 l/ g4 ~ set my-phase -1( }( k. s+ [, x. k- B
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets, h+ K9 H, J# @) {3 @4 ?
set roads patches with/ D7 O& K! B+ v# e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: } c% O2 T. F0 ~: ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! N6 D6 `/ l+ b+ V8 O8 q
set intersections roads with" w6 r9 m- e8 o8 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 j# C1 V+ p# X p. E' o I1 h3 J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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# }4 j+ A$ T$ T/ o8 H ask roads [ set pcolor white ]
" Q# N8 M6 R3 ]5 j setup-intersections
# }8 H Q* l7 E2 M: _" Tend
2 Q4 z# s. v0 [# k+ m, m% X8 u! b其中定义道路的句子,如下所示,是什么意思啊?
- y" o. S) m8 _/ U$ s% N3 O1 m7 A0 i set roads patches with
: m# s5 G( g( E# U4 l/ H: O0 i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ R# f4 ?( T" X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 I' ]7 r( [5 P% y4 T7 D2 p2 O
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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