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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。% e9 P. k N' k1 L9 @' a" D/ G1 a
netlogo自带的social science--traffic grid这一例子当中,
( r( E" d3 c7 ^8 M5 |. lglobals: N5 u7 O0 g/ D9 L
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* P9 ~. W/ z2 U) W. [* v, s+ E grid-x-inc ;; the amount of patches in between two roads in the x direction
0 n2 v( a D; b* h& \+ b2 V grid-y-inc ;; the amount of patches in between two roads in the y direction& Z& V$ r/ q$ }! c+ a
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ l, k2 X% Y/ t! V6 _" a ;; it is to accelerate or decelerate
6 b' ~+ W% B. o7 p) Q3 s, \# R phase ;; keeps track of the phase& `- Q# p, |$ p7 o
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ i- T2 x+ r% |5 m. I) i' g current-light ;; the currently selected light
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1 _$ G+ N: J- L r/ b4 f ;; patch agentsets- I7 Q+ B* b$ b, {; R
intersections ;; agentset containing the patches that are intersections
7 d) ?5 t8 V1 H) ` roads ;; agentset containing the patches that are roads8 R1 }7 ~3 B1 X& y2 s& {
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% a! s1 N- @) X' f2 l1 Jturtles-own$ x, Y+ X) V0 a) t8 k j3 E+ a
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speed ;; the speed of the turtle3 y, G& I. d$ l
up-car? ;; true if the turtle moves downwards and false if it moves to the right$ B/ r d% T% d. W W
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads$ a. Z6 M% u+ a n: S, P1 i: v
green-light-up? ;; true if the green light is above the intersection. otherwise, false.! \6 Z0 s# [3 z% r
;; false for a non-intersection patches.3 ?& b: z4 O# I1 z
my-row ;; the row of the intersection counting from the upper left corner of the/ i/ |! \6 g+ }' H* a+ N
;; world. -1 for non-intersection patches.
4 a5 V9 u- n) u; l4 O% h my-column ;; the column of the intersection counting from the upper left corner of the
4 @$ t1 q& @5 m! x' S6 t F" _ ;; world. -1 for non-intersection patches.
% D9 O* Q1 O) \4 q1 |6 n2 R2 l my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 ^7 ? \' e7 q' |" |+ f auto? ;; whether or not this intersection will switch automatically.
) W/ Y6 h! g9 J" r" i3 I ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 U. M0 o# O+ Q( ^' ?' l$ e6 Q6 O;; Setup Procedures ;;
( v6 |/ J& Q- \2 G3 n: F+ I;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.: Z$ q }% J2 c. ^1 }/ |% z
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 v5 a9 i/ K$ o1 b+ k8 g# M;; be created per road patch. Set up the plots.
: X' ?" t( ^0 o9 S7 Tto setup: S" ~! X( g1 N% g9 r2 p) {
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setup-globals
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+ `, f+ X3 k7 c8 g ;; First we ask the patches to draw themselves and set up a few variables* k2 n) D: \7 A/ x2 w7 n) W1 @
setup-patches& g+ d0 Q% F( n# Q/ j3 Z5 o
make-current one-of intersections% z4 t; o/ L5 ]7 P' C5 K
label-current& g( D: i/ Y( f7 \, {
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set-default-shape turtles "car"
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/ g. v1 {6 y7 V, ~, l9 m if (num-cars > count roads)2 V) a( C. O" h6 L, K/ ?0 G
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, B8 ?0 E3 a% `- z! w3 k user-message (word "There are too many cars for the amount of ", _$ y' c* q' U. ~& F2 F0 ~) }
"road. Either increase the amount of roads "! n) I0 u( R, O
"by increasing the GRID-SIZE-X or "
: r; Q4 r3 _6 m "GRID-SIZE-Y sliders, or decrease the "
1 P) S8 L4 [% x3 J9 B9 T! b) C "number of cars by lowering the NUMBER slider.\n"
5 @( f, d) E- M. }; K% y: \* s "The setup has stopped.") |7 j9 R9 _2 f
stop
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+ w$ S9 E7 u. Z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: _) s; U4 }3 ~ crt num-cars& N3 |, i3 W6 B( h
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7 {$ n7 Z3 @& C% [1 z1 a setup-cars5 z/ y3 H* P! a5 o: l5 K+ P+ A
set-car-color
* U0 V q" V$ l% Q) c( O" K record-data
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;; give the turtles an initial speed
' {, G9 H6 A5 x6 V& u: {8 U ask turtles [ set-car-speed ], B( |( S0 d" L
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reset-ticks
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5 K- ]% q2 c" P8 r1 ^) };; Initialize the global variables to appropriate values
7 F0 Z& d. X8 y1 }* }' Q5 H( Z' l eto setup-globals" A3 }1 F7 ]6 d, e1 v( y
set current-light nobody ;; just for now, since there are no lights yet6 R/ E5 t1 F/ @6 ?0 r, b: c$ G6 f1 I
set phase 08 E7 O4 N+ L9 ^ s+ e% \. Q( A
set num-cars-stopped 0* A& l& A: u, ^- G4 r
set grid-x-inc world-width / grid-size-x
4 a8 O- n0 g$ G+ j$ I; M) B set grid-y-inc world-height / grid-size-y, F9 A2 Y5 J8 x
' c+ I6 u9 T+ t# L: I ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ @6 s2 O" t3 _3 T& O" T* } set acceleration 0.099
$ L. V, r8 U8 {5 o" S3 p* Dend# _5 |* h, T1 ]2 Y, h* z6 z
! ?+ f/ {# x+ C9 M+ _7 k7 N; e;; Make the patches have appropriate colors, set up the roads and intersections agentsets,' z# h' `8 c8 e B" l/ R( Z( u. ^
;; and initialize the traffic lights to one setting2 _, \# y! e7 e& D
to setup-patches
8 L' p8 S6 E: F; W0 e$ j ;; initialize the patch-owned variables and color the patches to a base-color4 `* ~. ^9 U D7 s o6 V
ask patches
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set intersection? false% M. o0 {" m' g" H' a
set auto? false
0 y% b- o6 f2 B* C1 R+ n) {0 A set green-light-up? true/ h& x) {& D: ?5 C" ~7 n" ~$ B/ x
set my-row -1( X k+ C; i5 [$ w" @& a) g
set my-column -1
; a' P1 \& O$ N& N! ] set my-phase -14 q. {9 j) r, }( N5 _
set pcolor brown + 3
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1 H7 C- I1 @9 i; ` ;; initialize the global variables that hold patch agentsets
/ ]! z+ W! q5 I/ a) q set roads patches with
- z) A6 o/ ^, J# K$ D5 O; q: h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; z' a! p5 w: C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. h8 }2 r. V/ Z3 }) F2 } set intersections roads with& _4 f2 |, N) B. t {
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 G/ E& K) I( J' |4 W; E- z6 ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
9 Y+ a5 Q4 o6 ~" W; t 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?
\/ L4 O3 O! {& N0 U% | set roads patches with8 K, S9 s- Y- {# b" v! k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! \5 T. s; Y, k9 r# b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ x! h$ M6 v. F- z7 {. }; ]' k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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