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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。9 [4 Y* W, r8 w# o; Q
netlogo自带的social science--traffic grid这一例子当中,
4 b$ |2 u a1 m9 \( ]& iglobals
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: S$ m1 R7 o. a6 @# t" c grid-x-inc ;; the amount of patches in between two roads in the x direction
) U X: T0 I3 B; z, p0 P grid-y-inc ;; the amount of patches in between two roads in the y direction F( j& \6 R6 i- Q
acceleration ;; the constant that controls how much a car speeds up or slows down by if
6 o% g7 \1 O; C$ S B3 V$ U5 j ;; it is to accelerate or decelerate9 d( j6 A! G! s5 H; Q
phase ;; keeps track of the phase
: `5 Y/ K6 r, B) a. G num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 W- Y9 c- @& N/ m/ B current-light ;; the currently selected light% d8 r. V) w% J# ^
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;; patch agentsets
7 l" G1 ~7 s3 r& t% U- i intersections ;; agentset containing the patches that are intersections3 ?# o. Z! E3 _
roads ;; agentset containing the patches that are roads u( E2 [8 Z$ F7 L! a/ T
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3 I( Z V0 ~, G3 ]$ H% Z1 p8 q3 |turtles-own
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speed ;; the speed of the turtle
! ^8 K) ^& c* l- H9 m up-car? ;; true if the turtle moves downwards and false if it moves to the right
: R/ ^( d# L+ s2 m2 y wait-time ;; the amount of time since the last time a turtle has moved& }1 G" Y2 v2 B0 U
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patches-own% ~# a& h' Y/ Q. Q
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( F6 F4 D3 |) p. D) _ intersection? ;; true if the patch is at the intersection of two roads( H9 w( F7 D7 x7 E' A0 l
green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 ]2 B6 w3 B1 V( z4 c
;; false for a non-intersection patches.6 z2 ^+ O4 S2 R- m+ d/ a8 h6 U
my-row ;; the row of the intersection counting from the upper left corner of the0 [* _4 y1 t" h! G, V& {9 w5 P
;; world. -1 for non-intersection patches.$ q: t4 D+ I( j# z( A1 M
my-column ;; the column of the intersection counting from the upper left corner of the- R# |- u4 q4 Q2 G! i3 L
;; world. -1 for non-intersection patches.
7 z; l0 O) p' T+ v, Y, U& c my-phase ;; the phase for the intersection. -1 for non-intersection patches.! _: R- Y$ s/ A" i1 Q4 Y5 {5 c
auto? ;; whether or not this intersection will switch automatically.
; |* ^/ J K8 m! K% p ;; false for non-intersection patches.5 e: U5 U4 Y6 w9 d
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;;;;;;;;;;;;;;;;;;;;;;, @, `% f! `& |; t8 |' [
;; Setup Procedures ;;. i. N8 C; I/ A+ l I& h9 O
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;; Initialize the display by giving the global and patch variables initial values.
9 ?) h1 N& P9 S2 d+ m;; Create num-cars of turtles if there are enough road patches for one turtle to. Q' a' l. n1 y0 o$ J7 T
;; be created per road patch. Set up the plots.% y2 q% b* v: [' ^
to setup! `0 Q' e5 p3 _4 R& M7 m, z
ca
7 f+ U( k2 v* T) a! Z1 d# f( _6 w setup-globals
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) i" T& v9 D+ H4 x ;; First we ask the patches to draw themselves and set up a few variables
0 ~/ O7 E5 B k- f2 m, N5 V6 [ setup-patches$ B/ x0 I6 k' m: b0 W* q2 a
make-current one-of intersections% q4 a( s9 w6 w$ G
label-current
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, G: Y4 H1 h) b) f set-default-shape turtles "car"+ {" M* Q6 E+ L! W7 Y4 y
y6 E9 O5 T+ u& ~& r. I ? } if (num-cars > count roads)/ y. ~9 I' `- _" a! ^
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" y! v. k5 w/ d6 T user-message (word "There are too many cars for the amount of "( Y X3 Q1 v u: `2 R Z
"road. Either increase the amount of roads "
2 i& T$ e# u$ n! b) l2 l "by increasing the GRID-SIZE-X or "
0 x3 ?$ U& v# O0 v "GRID-SIZE-Y sliders, or decrease the "5 z# V2 ]9 y9 g1 n T1 O" J+ m/ C
"number of cars by lowering the NUMBER slider.\n"
8 _$ u+ P; P; J& K "The setup has stopped.")
& q( O. k+ s7 ^4 s- k9 q8 n8 n9 b stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, ]+ \" I2 q' i" X! o1 L
crt num-cars8 {: Y, {) \# b8 m' h9 C/ s
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2 H& Y- K. B1 B, q6 x: ?4 ^ setup-cars4 Q* V5 C5 h2 }$ R, q8 I
set-car-color: P! Z. U8 } b, f; Q3 y
record-data
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& X) | W$ E. }6 ~: U; u9 _2 ? ;; give the turtles an initial speed4 a8 B1 i) l2 m. N6 S0 r
ask turtles [ set-car-speed ]
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% K& ~) F' G) U/ I* l reset-ticks& a, W( N- B5 b2 k
end
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, p# b* @5 @7 d, y& \- k9 R;; Initialize the global variables to appropriate values0 ~& I5 p2 J" T4 ]+ N1 k
to setup-globals
0 q( E3 H9 U8 f' z& [% i" y set current-light nobody ;; just for now, since there are no lights yet! \% D$ |0 ?: x2 t% o0 V$ E/ ?- r
set phase 0
$ ^: Y2 A6 K! d0 ]+ `6 ?2 Q( m set num-cars-stopped 0) v2 d* Z, v& Q
set grid-x-inc world-width / grid-size-x
5 Q4 q1 W+ t" X' k9 E set grid-y-inc world-height / grid-size-y
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: b% T+ d Q" l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* S3 c3 D0 M) r, {; | set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
- l( b' N& q, o) Q$ B;; and initialize the traffic lights to one setting
0 t0 {! v3 w% p) z$ q: u' ]to setup-patches
; ^% D9 }1 }2 ~" l# h% K1 M ;; initialize the patch-owned variables and color the patches to a base-color, {8 E4 N) }9 c3 h; W
ask patches
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, r1 b/ j& e: e( f/ o5 b2 D set intersection? false
$ w; }7 W, |3 x; Q7 D; ~3 L set auto? false+ V2 o' F& l X/ j) j
set green-light-up? true
2 K, J: Q M! s* @; e3 m+ W set my-row -1
9 a1 p( H _' H/ ~3 P set my-column -1
2 n0 `# v9 p- r% V0 M! [3 k. z set my-phase -13 `" g8 k3 |$ r# g
set pcolor brown + 3
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! \4 Q- s% \' v ;; initialize the global variables that hold patch agentsets
A9 g4 D% B$ W set roads patches with, p8 B. s7 k2 @4 R3 q4 n% v5 K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 n. V* U! c& a, B) T0 H. f- A( [7 i3 _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 r! t& Q( o4 u) q J
set intersections roads with
* Q0 m: U; w1 H& n* W" } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; v) q: G5 S5 \, x9 Z" M+ d( ?# b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]# j+ X( X( b5 Z$ V l) T% D8 d
setup-intersections
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3 d3 F, @3 b* E x! {5 v. m+ B其中定义道路的句子,如下所示,是什么意思啊?
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[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 R, s- c9 v# h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 @. |+ N ^: Y* \8 C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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