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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。* u0 b7 s$ z1 g5 d/ f* M9 G( M
netlogo自带的social science--traffic grid这一例子当中, u5 t3 P" d* R0 ]5 ?, y! v
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction2 O, I+ v7 _2 K3 I
grid-y-inc ;; the amount of patches in between two roads in the y direction
8 ]& P u4 ~" ]7 [ acceleration ;; the constant that controls how much a car speeds up or slows down by if
4 U! @; W- u8 z, i( I ;; it is to accelerate or decelerate
0 w( b% Y8 Y( g7 v( w phase ;; keeps track of the phase
' N* }8 q2 h: f# G5 ^8 u1 y$ K num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) d% U) P* g$ m0 Y/ {+ S6 M9 m
current-light ;; the currently selected light4 t6 e: F" J& v) U, i+ W! l
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;; patch agentsets# Q. ?6 [5 ]4 F# ? m, A8 y. _& O
intersections ;; agentset containing the patches that are intersections
; Q8 ^) ~9 m( \/ Y$ J, T( c: ? A roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
! m/ o& T! r- c% D. {$ Q7 U. J' H up-car? ;; true if the turtle moves downwards and false if it moves to the right# k+ f, l: s4 h% \
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 roads7 Y) j2 Z1 p6 t
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 [6 B5 {5 m4 A8 k" I ;; false for a non-intersection patches.1 C8 G1 U" Y3 K$ P
my-row ;; the row of the intersection counting from the upper left corner of the; K# `( S" l5 C
;; world. -1 for non-intersection patches.
: F; B! y# s, ^7 w' W0 u+ z) c my-column ;; the column of the intersection counting from the upper left corner of the
# j: Z3 `" S. W( ] ;; world. -1 for non-intersection patches.
, u! M/ n6 T1 ~7 Z9 D my-phase ;; the phase for the intersection. -1 for non-intersection patches.* l' d1 x+ k/ [ M( Z# c3 n
auto? ;; whether or not this intersection will switch automatically.3 }$ W1 V8 Y7 V3 B$ ^
;; false for non-intersection patches." U' C# K9 B. s' A0 `0 x
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;;;;;;;;;;;;;;;;;;;;;;- r+ _% }' U9 z$ c4 @5 m
;; Setup Procedures ;;
; o$ S9 P! l Q N( ?1 C1 n;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.( B4 I8 [# U) ~3 i
;; Create num-cars of turtles if there are enough road patches for one turtle to
* n1 h7 \" R4 l/ ^4 b F;; be created per road patch. Set up the plots.' X- {; P' Y9 ?
to setup
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setup-globals2 N5 ]* k4 D z1 _# m% D i
! V3 A* J5 l2 R1 T- Q* r ;; First we ask the patches to draw themselves and set up a few variables
, E/ Y7 o* f3 o, x setup-patches& c; g4 a; u1 o! s# a) \/ Z3 P
make-current one-of intersections: K; I* {- Z; W5 K X6 n
label-current
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& g2 j \0 @( V/ | set-default-shape turtles "car"
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9 O* S9 n6 `; O if (num-cars > count roads)8 H7 D C" @; L8 s
[
! m; X! f: P6 ?9 P2 t* T* M& @ user-message (word "There are too many cars for the amount of "
5 L5 \4 m( D7 O, o; A "road. Either increase the amount of roads "% @ j& g# i& u& G6 T4 w" ?+ X
"by increasing the GRID-SIZE-X or ": Q4 \6 a& ^( J6 L& `5 `4 z* V: d
"GRID-SIZE-Y sliders, or decrease the "5 b& m! J7 T! x- T
"number of cars by lowering the NUMBER slider.\n"8 f3 U7 R I5 ]0 K
"The setup has stopped.")
$ B' t: t K# M/ ` stop( r' p3 H& w! v" G& N1 j
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9 i3 s) F( i" d9 @! Z) R ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color( d: `2 Z. q9 \, H* M) |
crt num-cars( `" f$ r5 M* T, J3 C" }( N
[
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set-car-color
7 w* ~% ]$ k8 O! L1 y- ` }0 j record-data
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, O; e6 |' X, B/ W6 ^2 N- n A ;; give the turtles an initial speed# T: \" Y/ I, p( u: c, A1 U
ask turtles [ set-car-speed ]2 e3 m8 D' R8 v8 z0 t: |9 P2 q
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reset-ticks/ E2 T& ?8 S% H% w' r
end6 W, b1 r% b' \5 ]; A
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;; Initialize the global variables to appropriate values$ {8 ~% c% T. R& y' J3 V; s2 P
to setup-globals
1 R( ?. M( k7 b! L set current-light nobody ;; just for now, since there are no lights yet# V0 Q: e' O7 [8 m9 G& d7 J* n& i
set phase 0
2 x/ g" L) N9 T5 z% S1 n: M set num-cars-stopped 0
/ A9 s& z/ _3 W2 B) o& f2 i set grid-x-inc world-width / grid-size-x
! h9 \ V# x3 j( R set grid-y-inc world-height / grid-size-y+ c- z! C( T- w7 t- `2 X
; R0 R7 W) _( |8 G2 h* ]- n8 M ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary F8 ^2 [( U: k6 e9 `
set acceleration 0.099
# v, P; ~) p) ]$ Lend
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5 y& Z! J& v8 |; Q8 x! a( v5 h;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 h/ O% l6 c# z1 L, O+ c;; and initialize the traffic lights to one setting
- l. E" {6 [% k/ p. Bto setup-patches
( b+ P" Q( L7 N ;; initialize the patch-owned variables and color the patches to a base-color: k. P( m2 s! Y+ Y) r
ask patches
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$ i; l% }+ _$ |: C, | set intersection? false6 E3 w5 E' ?* X8 ^/ l$ |" s3 z$ k
set auto? false
. D2 r/ r$ f2 {. Z3 v" R. j. A set green-light-up? true
' R- v' e7 D! `) c set my-row -1
( R; m& M! \0 s3 r0 A' M+ N set my-column -15 y# m0 G, J0 d2 r4 D) u, }
set my-phase -1
2 w2 R( |# ]" c) W: H; u set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets8 t3 P3 S% g0 {# w/ E4 {
set roads patches with; B8 o. F0 v6 u7 }3 B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 {1 ?) j2 ~& ~+ V+ `, w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- s* r6 I: X$ W
set intersections roads with
0 L; {4 C8 D5 _0 K' {! j/ S+ t- ?' k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
1 b6 _: _9 H+ G; \) { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]1 S% O( \7 a3 {+ P
setup-intersections
" ^ v% S" S* u8 |' Y0 Rend
' w1 |# q7 p3 G# r7 n& _其中定义道路的句子,如下所示,是什么意思啊?
$ J' ], J& Y/ X set roads patches with0 O+ ^+ @$ J- D; u, E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 t [. g6 ?- `$ y U2 G- c6 a2 ?* J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 m3 H3 d2 [# j
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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