设为首页收藏本站

最大的系统仿真与系统优化公益交流社区

 找回密码
 注册

QQ登录

只需一步,快速开始

查看: 11211|回复: 0

[求助] 在看例子时有几个问题看不懂

[复制链接]
发表于 2012-6-20 08:59:43 | 显示全部楼层 |阅读模式
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。  A2 K* a# G/ b+ ?
netlogo自带的social science--traffic grid这一例子当中,
8 {) i3 Z8 q3 L' Vglobals, M+ z8 a! D  A) \$ u
[& u) u) r% g% \7 ^* P+ l1 v7 a3 T% P9 R
  grid-x-inc               ;; the amount of patches in between two roads in the x direction  m2 N; M9 i# q4 _* [; A
  grid-y-inc               ;; the amount of patches in between two roads in the y direction( h/ D2 T$ L1 r# C) }
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
4 c0 ^; {( M3 G9 e( Z                           ;; it is to accelerate or decelerate
" \3 t: W2 o, }) l  phase                    ;; keeps track of the phase& B1 g: u/ `4 o7 W- A2 O0 S
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure; A7 B  j% {( ]4 E- D7 Y' p  E: o
  current-light            ;; the currently selected light) z( _% F3 E& a# e

( `9 @8 X( U3 b# V% Q  ;; patch agentsets
* {3 t; P, _0 g1 {+ G  intersections ;; agentset containing the patches that are intersections
8 j  P9 x: \  Z8 E4 Q4 y6 H  roads         ;; agentset containing the patches that are roads5 Q/ y) @5 C: Y( u; }2 ]& k
]5 k9 P. h' u6 r1 ]

& ~; x9 y! J# m5 d# o& u% |turtles-own. u1 ^- R5 z. ^0 m# b- Z6 M
[1 S2 I# w( Q% P! k% b6 }% S" A$ B
  speed     ;; the speed of the turtle
+ X' @0 ]3 p9 |/ K! H! K& v! x  up-car?   ;; true if the turtle moves downwards and false if it moves to the right1 ~% ~& @7 l+ R% Q% y/ ^8 T
  wait-time ;; the amount of time since the last time a turtle has moved
; [1 s8 o/ o) h]
% Y8 T/ Q9 n8 @
5 P5 s! t, B$ O* l" w- ~patches-own
# O! P# X' A3 A$ C* |7 `[! M4 e. f) O4 w- m$ ]; o/ s
  intersection?   ;; true if the patch is at the intersection of two roads+ T- X  x9 j  E
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
; W4 [5 D: R+ ~5 a4 ?                  ;; false for a non-intersection patches.
) r( F, p. W& g, N" D  my-row          ;; the row of the intersection counting from the upper left corner of the
4 ^4 Y8 H1 e9 H- a' b! k' a. Y( s                  ;; world.  -1 for non-intersection patches.
. }6 w+ v2 Q# i3 I; y/ _  my-column       ;; the column of the intersection counting from the upper left corner of the
7 t. `9 }+ ]/ q                  ;; world.  -1 for non-intersection patches.7 d; P5 {: l; L2 h4 \
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
. y: S. J6 j- C" a  auto?           ;; whether or not this intersection will switch automatically.
5 }* F; V7 g6 y, R                  ;; false for non-intersection patches.3 n( b2 L. B1 ?" q1 M! {
]! [; D7 l! l" B: m' E+ |) B

0 V  ~/ j* t" ^9 F
/ u4 `% ~" w& Q+ n;;;;;;;;;;;;;;;;;;;;;;# ~& |" d" M) ?9 M: J0 J
;; Setup Procedures ;;
& F! I3 u6 g6 U;;;;;;;;;;;;;;;;;;;;;;
6 Q$ S9 e: M5 F/ ~5 ]5 |+ ~  i% e, i4 Q1 g7 J! H. V* _4 |; I
;; Initialize the display by giving the global and patch variables initial values.
8 w5 b. ^) I4 i; v7 U( f/ L" k* H;; Create num-cars of turtles if there are enough road patches for one turtle to* L2 |9 s: [" g* J
;; be created per road patch. Set up the plots.
  w% l7 |& O+ f6 K6 Wto setup5 {! m, o0 d) e! g- D: p
  ca
+ n. N& x6 _3 w% e; c7 y# R# Y  setup-globals1 p6 g  n. K  Z5 U* `
3 g7 O$ g+ ~7 P  u' e+ h0 a3 e
  ;; First we ask the patches to draw themselves and set up a few variables/ O0 q/ J$ Q! d) E/ H9 X
  setup-patches% R/ g( z1 }  P, ^' n
  make-current one-of intersections) C, \: p$ a. Y0 t* L6 J. n7 j5 m. ]
  label-current
9 q% y9 j( Q# H0 s) _- b7 C2 P, W0 e/ O9 D2 E" x/ x( I, d+ x4 S( q$ }" u
  set-default-shape turtles "car": t* Z: Z- ^" |& M. Y

( \1 v$ |1 V9 ~  if (num-cars > count roads)
0 X: ^2 S" n$ u) O  [" \' l- E' M$ }: r4 l
    user-message (word "There are too many cars for the amount of "& ^1 |$ m$ {8 q
                       "road.  Either increase the amount of roads ") `6 O3 N. B. Z+ t3 ?
                       "by increasing the GRID-SIZE-X or "$ Z. O; [, I4 H) `
                       "GRID-SIZE-Y sliders, or decrease the "4 r' r8 Q, d- e, D
                       "number of cars by lowering the NUMBER slider.\n"  R- V' H/ Z% R
                       "The setup has stopped."); E% ?3 G, i; M8 G
    stop2 v3 ~* e2 d& e, w3 l& F2 H$ C' I
  ]
0 J) a; A, @9 q3 D* r4 a6 L( O$ k0 O6 t/ M
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 e7 q( z+ {7 I8 I+ ?- v& l
  crt num-cars7 N+ `1 [1 @! ^. ?, T/ G
  [
0 ?# n( K! B5 a* C5 G    setup-cars4 x$ V" K8 a! H6 H- z
    set-car-color
! e+ J. h2 z6 B' }3 q/ h    record-data
/ }2 L/ o9 p& u% j) w$ x+ z. E  ]
( D/ s7 h$ p( }6 @  k# ]! p: {  Y/ e5 j& S/ B' q6 P3 v* F( d
  ;; give the turtles an initial speed
9 k: d" l. V7 T) h/ h/ p9 d* a  ask turtles [ set-car-speed ]
, f) s- o- E' U2 p$ d3 \* Z
8 y" [. B! X$ _2 @/ ]  reset-ticks
* h  h% u$ Z5 R6 V( x, U3 ?% dend: t; E2 N7 c- k, `) W  K- ^' N' u( u
% N5 C; h8 j! x7 p
;; Initialize the global variables to appropriate values
! h" ^6 z) l% k  d; m2 k+ Ato setup-globals; d1 f) ~2 d2 r  v$ ]0 a& w
  set current-light nobody ;; just for now, since there are no lights yet
" I9 r: K0 \: b- [& m* R( R6 d- @  set phase 04 L. w! {: d; S' [
  set num-cars-stopped 0
( R7 Q' m0 \) c5 u6 X$ t1 l" ?' C  set grid-x-inc world-width / grid-size-x
$ U% @/ ?) X5 M% T  set grid-y-inc world-height / grid-size-y
* Z0 x! U0 C4 R8 W* {$ k3 j: h7 N% x2 G; m& Z0 J  n% t8 J
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! `, o6 t  B  Q& s
  set acceleration 0.099
% B& _  c0 f" c1 p% _1 Q2 Pend
' N( i  L) q8 ?+ _3 h! q8 C$ B' G# K" d$ {; h/ M/ Q! o2 p7 M4 N+ z
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 N  t  z, d. ?( d& ~9 s
;; and initialize the traffic lights to one setting, m* @: j1 G3 l- `* u* a  O8 d
to setup-patches, ^  a# y: E: ]: W0 r2 o
  ;; initialize the patch-owned variables and color the patches to a base-color) I0 R$ c, X3 [1 P! k4 }
  ask patches
- v, A1 R$ C# W8 p5 Z* `0 E  [
5 y$ h- F; n& y& U1 a2 K( X    set intersection? false/ W5 p$ s  \6 o! K0 r
    set auto? false
/ ]; v# r1 Q$ j' Q( N6 C    set green-light-up? true
) N8 h7 V/ t( d    set my-row -1# x, A) u( T+ Y0 `1 o
    set my-column -1
( f! Q5 _6 s: a5 x    set my-phase -1
3 q& t1 ?5 f$ j" W  |( [    set pcolor brown + 3
2 b  U  o% l6 W1 D, |$ g* G  ]
" y8 n/ C6 p5 b2 a( A# q; @1 y1 }' q
% V1 {0 n" K: B0 s  ;; initialize the global variables that hold patch agentsets
, ~( v! x  I& H6 h8 ~8 [% g  set roads patches with
' t& J; ]. i, A) `/ E    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) S2 G% _, @* @" Y
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 v% w4 S( A, W$ X
  set intersections roads with" J( w5 t0 e& f1 W: C1 G
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 y3 E; v3 t4 q- Q7 p
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* m. h+ |, f' H
" [7 A0 ^' |( L# A+ H0 K  c4 e  ask roads [ set pcolor white ]- j1 d* q) t% G, @3 r- T
    setup-intersections
8 [7 w2 k4 |4 H: Q' r1 [6 o9 {end( Z/ W7 m' F$ C) K  R: S
其中定义道路的句子,如下所示,是什么意思啊?( g$ E6 G) ]1 Y
set roads patches with7 ?! R# f2 @) n7 Y) x
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! e- i6 X# R8 u
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) h  H, z8 P4 V/ M, }9 F# p
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?
您需要登录后才可以回帖 登录 | 注册

本版积分规则

QQ|Archiver|手机版|SimulWay 道于仿真   

GMT+8, 2026-7-19 15:43 , Processed in 0.013705 second(s), 14 queries .

Powered by Discuz! X3.4 Licensed

© 2001-2017 Comsenz Inc.

快速回复 返回顶部 返回列表