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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 L; r8 g$ A2 s5 Q( s, }8 N
netlogo自带的social science--traffic grid这一例子当中," g7 h0 m; }1 h9 K; b( I- r7 z
globals- F; r3 s% q+ c$ E; p' W" o! Y1 s0 h
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grid-x-inc ;; the amount of patches in between two roads in the x direction k, O3 l3 ]: D. D
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 d5 c1 j$ D6 T7 k; q; c5 x acceleration ;; the constant that controls how much a car speeds up or slows down by if! D2 x3 F* f9 ^8 Z1 `+ A% E( T
;; it is to accelerate or decelerate3 l0 ^" d' H# K! j) c$ c
phase ;; keeps track of the phase
. Q f* x% V. ?& X& K# h" B& S num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
( U' Y" T, ~: ] current-light ;; the currently selected light
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;; patch agentsets8 ]1 d2 v% ~4 x. m# L6 k
intersections ;; agentset containing the patches that are intersections4 Y/ U3 i$ p/ C' p6 E6 o
roads ;; agentset containing the patches that are roads
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turtles-own
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: h/ ` I* J# ^, c speed ;; the speed of the turtle
- [+ F) i; ~$ c I/ Z; Q# j- z up-car? ;; true if the turtle moves downwards and false if it moves to the right
- ?/ D% E, N4 T$ Z, _ wait-time ;; the amount of time since the last time a turtle has moved9 R6 Q/ |8 g: y A$ N
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patches-own
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% v6 Q F- i( K J( J) z! x intersection? ;; true if the patch is at the intersection of two roads$ i; V$ L4 C7 t' A
green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ o) ~4 x3 b9 ]/ w" B, ~
;; false for a non-intersection patches.
8 X0 ?2 w8 j0 m! f my-row ;; the row of the intersection counting from the upper left corner of the
$ \9 Q$ i E: b6 j2 m, X ;; world. -1 for non-intersection patches.
2 C& c( `0 U& Z& M# o8 ^ my-column ;; the column of the intersection counting from the upper left corner of the
; v8 ?9 e4 q$ `4 `3 |5 `& ^; Q6 } ;; world. -1 for non-intersection patches.$ X+ l; C: {3 w( ]/ G1 v+ K2 V% `, O
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 @2 X9 s% L8 c auto? ;; whether or not this intersection will switch automatically.
6 b4 R: Y/ H; y: d ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;7 v* y. I$ g8 m2 r( b# W7 h0 F
;; Setup Procedures ;;5 H# s9 q3 c3 a3 ]- N0 Z+ ~
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.4 [" F& W" G U* s: ~3 d' |/ {
;; Create num-cars of turtles if there are enough road patches for one turtle to' D F9 y% X- [4 L
;; be created per road patch. Set up the plots.8 a9 q' n r; Y" K( e
to setup0 ?' S$ ~' Q$ ^0 r( ?
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables% e6 e& q3 S# G8 D5 K
setup-patches
; Q l, O: f M/ N3 t) m8 e make-current one-of intersections
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8 @4 S) k/ P# g2 Y8 Y set-default-shape turtles "car"
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if (num-cars > count roads)! R* x2 `8 @+ P, x
[
8 f2 Z5 Q5 J- l3 F, B) P user-message (word "There are too many cars for the amount of "; G: \# p! r+ ]
"road. Either increase the amount of roads ": h h4 g7 h, V: s! d
"by increasing the GRID-SIZE-X or "1 ?8 \; k5 M, D
"GRID-SIZE-Y sliders, or decrease the "+ W9 z8 _( |$ O: b; z6 a
"number of cars by lowering the NUMBER slider.\n"
+ r- }( F+ h8 K$ C* F "The setup has stopped.")9 ]/ k7 F* r0 A+ @
stop8 a; \; S/ q) q' n6 G+ X
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ A( o$ w& \6 D crt num-cars; _ E- m' T/ @, s
[
8 \4 l/ T7 O7 d& t setup-cars
; L& O) C8 M/ n1 A+ v) e set-car-color; F/ F6 v0 T8 t& ^* a8 p
record-data' J/ A& |* ^ }- E7 l
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1 C: y9 ^* t6 ?5 W: {7 l. {% Q ;; give the turtles an initial speed
+ E* C. w" K. T) w/ R' @& T ask turtles [ set-car-speed ]2 o/ I, m: c# O( t0 f3 W4 X
! D$ N5 a& r1 o* k- | reset-ticks
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$ r& h( w, Y( j7 C3 X& H" F;; Initialize the global variables to appropriate values
$ X, d% O' F) y' _8 Kto setup-globals: J; y* W# x& z. {
set current-light nobody ;; just for now, since there are no lights yet, F2 `7 q b. [& n+ ?
set phase 0% J5 Y& J/ n$ g$ J. W
set num-cars-stopped 02 i& A( @( ]" U9 Y! N% x( _! ~
set grid-x-inc world-width / grid-size-x
( ]8 ]3 _. ^, F, \' P* e! { set grid-y-inc world-height / grid-size-y' u. J n7 v& V) r' @% W5 C% X& z8 m
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 M" _, h. B* R# ?, f% J6 R- p4 L
set acceleration 0.099
3 ^& q3 T9 |$ d; K3 {end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 _4 a e$ q! E, Q. b* n$ i# i% `& S;; and initialize the traffic lights to one setting
/ b( {& Q9 A0 R& P+ | y4 R3 h, zto setup-patches
s' H( }( E4 @- f2 C# d ;; initialize the patch-owned variables and color the patches to a base-color
/ F7 T! [1 w5 z) n& S ask patches# I; u% }9 v% {" {! ?9 k7 v$ ?4 G
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, Y$ x) D, B1 V1 Z% G; [' v+ o set intersection? false* J0 @: q1 g# d* V
set auto? false* R9 A( l f4 B( \" W
set green-light-up? true
# e2 e1 X/ d! ]9 a9 k7 m( B set my-row -1* J6 b* g* \4 K+ D- f; b
set my-column -1
0 L* {& c! }- c; R, w6 f& S set my-phase -1
/ C. F- H, ]% Z: ? set pcolor brown + 3 v( I" P/ u% e6 `- y, c
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;; initialize the global variables that hold patch agentsets- S. ~! W5 u$ g, J8 w$ G; ^
set roads patches with: x F1 w/ Z) G$ L, r4 R; a( D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ [0 Q* f' S& D' u" C: l (floor((pycor + max-pycor) mod grid-y-inc) = 0)] L- d; Q3 I }5 `9 ?
set intersections roads with8 i- T8 Y: W4 F- \% r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ I, o. J6 L) ^ B7 E* C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 X" F( G: p+ T+ |& Y8 u8 Y3 Q) K
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ask roads [ set pcolor white ]
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end' z* h( Q' r- U2 Q% z
其中定义道路的句子,如下所示,是什么意思啊?
: A z. D) e" M set roads patches with
2 S* n/ e- c: h. D3 U7 u, K+ n) N i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
}, n1 ]0 f+ \5 K3 x. \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( w; R5 j' x+ T, Z
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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