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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。0 Y( U$ W- N$ |+ }& L& o6 u
netlogo自带的social science--traffic grid这一例子当中,5 v6 A; x, b1 t. I2 _2 ]8 Z
globals2 Z) b9 k4 f' L) O+ m1 O& ]7 s
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# ^( M, x$ ?9 H4 ~! R grid-x-inc ;; the amount of patches in between two roads in the x direction; N; f/ j& J# O/ d U# o9 m
grid-y-inc ;; the amount of patches in between two roads in the y direction
; f( @( l/ v' n& f acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ j& v. F7 a, u3 K ;; it is to accelerate or decelerate- V$ Q% k! J6 _
phase ;; keeps track of the phase
# w5 H; ?4 i/ R num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, @% u7 }# j! ~" I8 B
current-light ;; the currently selected light
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9 Q' g+ v0 m# F# b ;; patch agentsets
7 a4 |# H7 Z5 V& G intersections ;; agentset containing the patches that are intersections
6 ^: r! L! i( { roads ;; agentset containing the patches that are roads- w5 N$ Y5 g% L9 i' e8 Q0 ~4 i
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turtles-own
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speed ;; the speed of the turtle( i' ]3 N; u; a
up-car? ;; true if the turtle moves downwards and false if it moves to the right# d' U* u0 I5 O C; |
wait-time ;; the amount of time since the last time a turtle has moved
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+ g1 F9 R$ e& {& w! V. K, A7 D+ ~patches-own6 W W, i" ^' `% b+ D- N0 E
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+ {0 c! n0 c! Y; Q# \ intersection? ;; true if the patch is at the intersection of two roads
, k3 u$ _1 h- n green-light-up? ;; true if the green light is above the intersection. otherwise, false.
) ?' X$ d2 o, F# A$ B ;; false for a non-intersection patches. F8 K: H$ o6 |' C2 [. z
my-row ;; the row of the intersection counting from the upper left corner of the X, R7 z4 Q! r/ S. `
;; world. -1 for non-intersection patches.
5 M. ~9 C" r* t& M) y! i my-column ;; the column of the intersection counting from the upper left corner of the$ t; g; y: ?9 G5 t
;; world. -1 for non-intersection patches.
% R& P. Z- i) C) ^3 a* I$ B- T/ X my-phase ;; the phase for the intersection. -1 for non-intersection patches.! s( V f4 x: s! D; ?
auto? ;; whether or not this intersection will switch automatically.9 b% l$ V5 G' `- y1 z" k2 u6 p
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;. F2 Q# I& q/ f" s5 Z# H: G
;; Setup Procedures ;;% r3 x+ z9 m, ?, g
;;;;;;;;;;;;;;;;;;;;;;3 z, }& N" e: l5 R j: t
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;; Initialize the display by giving the global and patch variables initial values.
2 x; r9 G" \3 y F% E8 p;; Create num-cars of turtles if there are enough road patches for one turtle to
* }4 Z) R+ b% n7 T f( c4 J1 b. d4 a3 L;; be created per road patch. Set up the plots.0 H0 {5 j* q8 X* b% Y7 N6 o
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
% p. P, ]9 c) \; b, w( N% y setup-patches
$ Z: k+ \% f% v make-current one-of intersections
% d4 y- A+ v( \$ K; Y" ]( ^* G3 H label-current* l6 L0 z6 y5 O1 B
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set-default-shape turtles "car"
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) I/ d" }% s p, P1 F+ ] p if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
" X, f* P8 O" v* G) T& e "road. Either increase the amount of roads "& M8 O" g9 V+ z) \: x' ? M) a" @! Y
"by increasing the GRID-SIZE-X or "4 }% f2 k8 V, K, ^9 W
"GRID-SIZE-Y sliders, or decrease the "6 K" ?2 g& P, \
"number of cars by lowering the NUMBER slider.\n"
* q) M- x& _3 q O0 S: u" w7 A, d8 R "The setup has stopped.")
) F. S; P4 x- b. z1 Q- x; Q stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! m. b# y- K- @6 R4 `* @* F
crt num-cars& r1 g' t; k1 p5 P& n F
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setup-cars3 i2 l6 G. h, O/ j7 }; @
set-car-color
; |3 U% N: z! y) ^7 [# M/ } record-data
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4 i2 n6 Y' [' a1 R; \' ^ ;; give the turtles an initial speed5 K8 L7 v! _% V+ |" O
ask turtles [ set-car-speed ]$ ?$ k* R) p: d+ c4 }5 g3 O
) w, W8 Z: U6 t( x5 O reset-ticks
% M" u: E- i* I. \end
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;; Initialize the global variables to appropriate values
) i! _2 R: w% K: Tto setup-globals+ y. J. V. q" C* g5 B3 _& X
set current-light nobody ;; just for now, since there are no lights yet
# j8 W$ ]$ H5 ]& |! G6 ?( I7 U* c set phase 0
8 E2 V# i! Y* m: ?$ X# g5 n set num-cars-stopped 00 K; p9 N/ k/ w( N+ w9 U
set grid-x-inc world-width / grid-size-x3 G& p8 D4 z, I. ~8 f7 P
set grid-y-inc world-height / grid-size-y- ^% j! U* ~" _! e M
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* Y& _. h1 F! c- a% d$ H6 z set acceleration 0.099
. U9 t. x! B6 `) Bend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 i2 W( I# j) [$ [2 m;; and initialize the traffic lights to one setting
7 p. A, R3 d- |: _5 k6 m9 tto setup-patches
6 H2 F- S' b5 | \" _ ;; initialize the patch-owned variables and color the patches to a base-color. h# D( F$ C, z
ask patches
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set intersection? false
' J% L _3 n9 s; U0 G5 T2 v8 I set auto? false
) w$ ~$ T$ j- c* v set green-light-up? true
- [& D! t. D1 J4 t0 z( P" o set my-row -18 T, s% M. T3 F) S) e# e
set my-column -1
~( H r5 }/ `" L set my-phase -1$ _& v- ` C' P) e
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets% ?! b( x! N9 V1 e i4 y, w
set roads patches with- F" K! p6 x+ b, h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 M1 k6 d/ j1 \& v2 } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% y. u$ Z8 E$ @! b$ `3 a set intersections roads with& B9 i1 Q! Z# v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 P: @" Z/ O3 e( |8 P) A- w1 ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 t+ O5 v# G9 Z" H. d9 ^
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ask roads [ set pcolor white ]) ~% T8 x7 ?1 y8 x- l6 L+ ^. I
setup-intersections$ E7 p2 O) Z' M% S- E5 {" q, B
end4 _6 R7 D) h" l' e
其中定义道路的句子,如下所示,是什么意思啊?
O1 a3 a6 i- Z, ? set roads patches with! A. _; `! G0 v; H( _5 q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, C$ D2 _( y0 A# Z# n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 \7 p% m% ]3 W4 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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