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: 9318|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。2 h0 t8 S8 [# v6 S% |
netlogo自带的social science--traffic grid这一例子当中,* t4 S* D& z8 j$ E  s
globals6 w5 Q6 P+ m0 u
[
2 Q, t6 _+ L, d1 e  grid-x-inc               ;; the amount of patches in between two roads in the x direction: a: G" N# n4 D! @" c
  grid-y-inc               ;; the amount of patches in between two roads in the y direction, r2 O  f5 ~3 X. f' e
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
2 Q. ~) E; [0 _3 B5 q0 d2 n8 z" W0 P                           ;; it is to accelerate or decelerate
+ |! @  h) Y5 _9 c4 O8 ]% d  phase                    ;; keeps track of the phase4 o/ J2 F/ d) C( W) `
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure1 F! W( A9 Y& B8 \4 `2 }. H: O
  current-light            ;; the currently selected light, X9 {! b# T9 e$ j: n7 Z( D

" U  \, @& b) G  ;; patch agentsets3 c2 q7 J8 y" C2 x% j* b4 }. G
  intersections ;; agentset containing the patches that are intersections
1 g" c  y8 f4 S5 x3 M! E0 M  roads         ;; agentset containing the patches that are roads% D* q2 \& T2 |2 _* ^( P
]2 j6 Z; L, ?+ A% P7 s

- R6 h# H+ B, @' l, ]: P  wturtles-own
) M' _* ]7 d+ k' g[7 v' k% m1 k2 X
  speed     ;; the speed of the turtle
# j: z5 s2 p' r% u- z' x0 i  up-car?   ;; true if the turtle moves downwards and false if it moves to the right8 G* ^* n1 E5 I1 g% \
  wait-time ;; the amount of time since the last time a turtle has moved
3 n: A2 s/ R; E]
# [; E) q/ n  h% }; G4 o0 H/ y  A& {) d& ]6 v3 f9 E
patches-own+ L0 u; b& Z% l$ l2 u) ~2 i2 H
[
) C& T. D  ~% H& T) F. j% M6 q  intersection?   ;; true if the patch is at the intersection of two roads8 ^  k8 `6 V4 H5 l
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
3 [3 l/ \6 H& n3 S                  ;; false for a non-intersection patches.$ s3 \% }! ]4 r2 X, N8 s
  my-row          ;; the row of the intersection counting from the upper left corner of the
( E* c$ w) P+ o9 {% e- o& i                  ;; world.  -1 for non-intersection patches.
: x/ L" i  v+ J" I7 _5 X  my-column       ;; the column of the intersection counting from the upper left corner of the
) r  J4 N% \% g) ?1 {$ a* Q                  ;; world.  -1 for non-intersection patches.
  [1 U6 u; X" i6 P1 ~! e2 U  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
7 H0 h: X2 x& z  auto?           ;; whether or not this intersection will switch automatically.+ j; ~: v4 |& b; c" O
                  ;; false for non-intersection patches.' I4 d9 D- A) |6 L
]
5 V3 |+ ~/ |6 Q! b4 g0 j# [& h: f- i; ?

9 e- A8 q+ ]5 H6 s1 w% h' b1 Z;;;;;;;;;;;;;;;;;;;;;;" k9 d# p  R' U8 t+ n4 N1 h
;; Setup Procedures ;;
8 O, n( I2 r$ j( \;;;;;;;;;;;;;;;;;;;;;;, ^  X' ?" I% }; l, ?2 \3 f

/ L, r, H8 B* _$ D2 M; E6 S$ f; x! B;; Initialize the display by giving the global and patch variables initial values.
" v& X5 @5 c# ^, w2 T0 W;; Create num-cars of turtles if there are enough road patches for one turtle to
4 ^# `: z6 n" b& p6 o3 R;; be created per road patch. Set up the plots.
( @% ]0 j% W1 F% a9 gto setup
. b8 k" S' Q; L& r  ca* ~% J# H1 ?) H5 F  C7 E
  setup-globals
- j9 u3 I8 |8 L8 P; N- m
; K/ a% x( P- F  ;; First we ask the patches to draw themselves and set up a few variables  B& c6 R5 E+ L0 [% `
  setup-patches
" d- u" H9 z/ D4 ?  make-current one-of intersections
1 e% E5 b7 e& U4 k  label-current# N& f5 d) L  q  u; \
& q9 s8 j* ?4 Z8 o% j$ Z
  set-default-shape turtles "car"6 G4 p: A7 b! |+ Y  q# ?3 x0 S# ?
3 v5 l0 i/ F5 `
  if (num-cars > count roads)
5 E* z4 X4 h" q# ~! ~- J% w- \  [5 u; @! v7 n+ W6 |9 S
    user-message (word "There are too many cars for the amount of "5 ~) I4 i, D- b  x6 `* j* M
                       "road.  Either increase the amount of roads "$ m% u2 I9 h. w5 E) i/ D
                       "by increasing the GRID-SIZE-X or "
6 l$ M; q3 Q/ e0 V                       "GRID-SIZE-Y sliders, or decrease the "
: Q1 O: s3 }1 P1 W9 S0 ^                       "number of cars by lowering the NUMBER slider.\n"& C# @  A5 p+ Q  Z6 b1 j
                       "The setup has stopped.")
: t+ s: b  g5 q( D+ H: O( {    stop( U& W- J+ j6 X1 @/ H
  ]; H' i7 y. U4 y) |1 h

8 @; Y. {# Y1 M" t; T  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' t& l6 J) z- `* A; D9 {
  crt num-cars0 Q  h8 m8 O4 ]% t8 i
  [. C& i8 o1 _% U: \" ^
    setup-cars
5 e0 `. V( I! l8 A    set-car-color
8 r+ D' P) |$ f$ F    record-data
" W& X2 c- b, f# J7 X, d, Q0 _  ]
1 G2 {  Y8 C4 c7 X3 _1 c' M( B) g) i  @5 `6 G7 k; ~9 E& W
  ;; give the turtles an initial speed' J8 w* D9 u* f; b! ~% E
  ask turtles [ set-car-speed ]
( ^. S4 ~- A% ]$ p2 E2 x; |- f* e# J7 n8 B+ ~
  reset-ticks# H7 R2 [6 L9 \7 }& D. M  d5 D
end
( |, `% @0 u6 g1 y
+ c/ l' n1 A2 {2 I( r# _7 };; Initialize the global variables to appropriate values
& X. C. a7 n6 z2 M( _8 u* |9 @& Lto setup-globals
, R9 X& S' [# N4 h  set current-light nobody ;; just for now, since there are no lights yet
" _1 r( f& I; {1 r  set phase 0  U* u2 E; b$ v" V5 N" x
  set num-cars-stopped 01 ^* `6 F) G5 l4 ~( M. K
  set grid-x-inc world-width / grid-size-x  C. i" p  F/ f# M8 {/ j  X
  set grid-y-inc world-height / grid-size-y
" J8 t, Z# \$ u4 I! o6 V: V% I( M0 ~6 r+ S
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* `  f. j8 y; q  set acceleration 0.099* J. s* k$ t+ d  G2 a( Z6 z
end- a6 _! Z4 s1 ]

5 i0 Z8 ^- e4 B+ Y- }* c+ v;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 Q( D# e1 B7 ]) b& t9 k;; and initialize the traffic lights to one setting: p( d/ s9 {2 `
to setup-patches
/ q2 U' R6 l# A; g; u8 S  ;; initialize the patch-owned variables and color the patches to a base-color, c; {  l; {6 O3 [  M
  ask patches
7 E8 e5 i8 m3 f1 o) Y, e, P  [
" h1 S7 f, j/ U" n$ P5 ~: i    set intersection? false
$ W9 ~4 M. A5 H6 y8 G. S4 {    set auto? false
% b& h0 u! P; A: w: K# U! {% u1 y    set green-light-up? true4 v" Y1 a: m) H
    set my-row -1. W) P8 i# O" Y& f/ Q! c8 P
    set my-column -1. v9 C# \" M8 r( t! b( h
    set my-phase -1) ?* |6 K" X+ L! _% t6 W7 ~8 l
    set pcolor brown + 3' v# d, N9 t* j! h& m* E$ m/ {
  ]& I% L' U" U+ m8 U  \% Y* E$ v" K, N
2 e' d0 h  c' T: K5 _
  ;; initialize the global variables that hold patch agentsets
7 e8 H. n; E7 L( `+ s7 ]  set roads patches with& _( `8 A3 `- Y# f
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 E" Z. V% I/ I3 y
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" A1 ?' P- P" F0 x) `, @
  set intersections roads with% p, X; w; c+ J/ @1 \5 i+ N9 j
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and  s5 R" Z$ Q5 P) \2 f/ D1 |
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( C8 Z3 f" j( N' K0 l. U5 `0 L  S
  ask roads [ set pcolor white ]
7 w5 R2 i( O6 R6 L    setup-intersections) i- A0 C( x6 J6 _; s
end+ \  k' b6 T1 h! B% D# W+ i
其中定义道路的句子,如下所示,是什么意思啊?% @7 s* A- y2 E2 W, b* E. j
set roads patches with
( d; x5 I- c0 o+ H6 D    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 }' Y" l+ A) O- s& K" B    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ t: c& Q) y1 }# @! L$ d: n+ f& o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, 2026-4-9 18:00 , Processed in 0.018269 second(s), 15 queries .

Powered by Discuz! X3.4 Licensed

© 2001-2017 Comsenz Inc.

快速回复 返回顶部 返回列表