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: 10184|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。
% L* F& I4 r. hnetlogo自带的social science--traffic grid这一例子当中,4 r, Z4 D; r$ V6 k' l$ M6 ~8 E2 y
globals
8 `' k+ j& ]: I! D[  Q8 }& m! K7 W+ J
  grid-x-inc               ;; the amount of patches in between two roads in the x direction! F" L7 Z+ l" P7 M
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
; h/ w0 Q- ~' F% K* z4 O  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
3 ^& m3 h4 ]1 l" O( D! S  f) Y' I                           ;; it is to accelerate or decelerate" e. F  E& j; G) v4 O
  phase                    ;; keeps track of the phase  D% G# [# {3 }- f
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure$ n% U, h, E1 j( |0 f- ?
  current-light            ;; the currently selected light
7 ^: G  e% w4 \3 K+ k5 \7 Q9 M0 f& V5 z
  ;; patch agentsets8 i7 y8 R/ O( K1 w2 e
  intersections ;; agentset containing the patches that are intersections
  L# D1 h4 e2 r. A0 u  F' v  roads         ;; agentset containing the patches that are roads, l$ y8 |$ o* K3 ^- i3 R/ \
]: D. a8 f  O! K8 j( H) u

4 w* F; l( ~* P9 i3 K* O( f8 Rturtles-own# v$ r+ S- p" o6 T8 m, D
[3 c- P5 n8 ~, D! e
  speed     ;; the speed of the turtle
4 S7 a& a! D4 d& _  ^: k' v5 R7 k2 ]# `  up-car?   ;; true if the turtle moves downwards and false if it moves to the right% `4 c; @+ S# J! ~
  wait-time ;; the amount of time since the last time a turtle has moved
" r6 q2 x) o- G* T7 k# x]
! N2 t# W& b9 Z0 F0 S/ l0 x
8 N' z' {( p$ N# H0 opatches-own$ ~* m$ m% M+ R$ \; e
[
; D1 p- L- p& B1 u/ B+ F  intersection?   ;; true if the patch is at the intersection of two roads5 A0 Q& f6 M. h7 j
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
3 c( }. h) h, q                  ;; false for a non-intersection patches.
9 A, F; J6 S4 I  my-row          ;; the row of the intersection counting from the upper left corner of the0 o$ {; C7 G! z
                  ;; world.  -1 for non-intersection patches.
0 t( M  T  W* H( [0 ]" E  my-column       ;; the column of the intersection counting from the upper left corner of the
/ P# }- R; Q) t0 @: i                  ;; world.  -1 for non-intersection patches.
6 {" `. P/ ]: Z1 n* V# A* W  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches., f8 c0 r: [* W/ ]* Y1 ]- w
  auto?           ;; whether or not this intersection will switch automatically.
/ v* _9 v! C" A  t) ]$ x                  ;; false for non-intersection patches.; l) v" [; z. t2 D0 d
]
$ i! H# v5 `: p3 \. S* G9 u3 N2 ^5 k/ j5 ?
. V% c" I8 o, L5 N6 M: C' F5 K
;;;;;;;;;;;;;;;;;;;;;;5 N5 ~  O5 S1 L) r
;; Setup Procedures ;;
2 @# Y6 S. H- H# m. j4 i;;;;;;;;;;;;;;;;;;;;;;) ?" C7 q6 R' @* ?5 w" Q

3 o2 h. {  `+ f;; Initialize the display by giving the global and patch variables initial values.4 w8 o4 a  X9 ?+ u9 _/ u% w
;; Create num-cars of turtles if there are enough road patches for one turtle to' P- ?3 O! v5 E; r/ p
;; be created per road patch. Set up the plots.* x7 [2 m7 A8 \% ]
to setup( z8 l4 }! c+ L) f: f% a  y
  ca; B7 C/ f7 b7 \% P+ B9 G
  setup-globals
" B+ X* c9 f7 _7 \# g! R0 X5 }; O! A
  ;; First we ask the patches to draw themselves and set up a few variables" u# p6 e, o( T& ~
  setup-patches: G0 m: }" I: z7 k
  make-current one-of intersections
6 [/ d; h2 R9 A1 S. F  label-current
; k7 ^0 |: F0 _# R8 i. D+ m# s6 ~6 D; c1 e5 _
  set-default-shape turtles "car"# J! e. y/ a- P. Z! `: _; t. m, u" H
+ M$ F& f8 R! f: ]0 t5 G" d
  if (num-cars > count roads)
# `: K; R) s" A) c  [2 w& X/ s7 P$ `9 {: K( X( Y& p9 f
    user-message (word "There are too many cars for the amount of ") e1 R. T0 E- ?1 _
                       "road.  Either increase the amount of roads "% d6 S6 A; Z& X& U+ R1 t
                       "by increasing the GRID-SIZE-X or "
. u. l( R1 E! g' @( L3 \                       "GRID-SIZE-Y sliders, or decrease the "
$ g+ q. C3 i/ `% l* i                       "number of cars by lowering the NUMBER slider.\n"2 U9 y8 O4 B5 K( j3 Y: K9 t
                       "The setup has stopped.")
& r9 r' x2 u! n0 t    stop
/ c: Y# l9 Z* q$ u  ]7 ^# t/ v. Y( Z0 I

6 ]3 M9 D/ H1 u. b% B+ ^  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color- K: p2 \$ r( \# O7 O5 G, ^" ~
  crt num-cars2 B& o5 ]) L) y, ^& ~) x  s
  [
: l$ {6 b& R# E8 x    setup-cars- m  x! k  ~7 ?$ X
    set-car-color3 f& U0 a& X2 V) ~% O
    record-data
0 i) s$ }! \1 i! K9 I8 J5 V9 X  ]( q4 C( o1 y9 @+ |
  J, [" s0 _8 A) p+ N( F& D, V# t
  ;; give the turtles an initial speed' H& m% [* m+ g  C- `3 M: D# Y
  ask turtles [ set-car-speed ]8 x; F5 b( z3 I" }4 n4 u7 j& S& R
8 l, t& [( V) M
  reset-ticks
  {* f1 _0 C) X/ H# ~end* L! y( Y6 ?7 d8 B

  |) H( o4 H2 s, w1 x4 E0 j;; Initialize the global variables to appropriate values7 ^, O, `) C9 c  m' g+ e; q7 |
to setup-globals
+ N8 p% A: y# V2 E; I  set current-light nobody ;; just for now, since there are no lights yet
" I5 o$ E  x# i/ _0 _  set phase 07 {5 u* [" C8 N: ?" u( Z
  set num-cars-stopped 0
/ ]- s* _& H9 v7 m* l  set grid-x-inc world-width / grid-size-x
/ a5 d8 c  }( O( K3 G  set grid-y-inc world-height / grid-size-y% m6 `! o% c! G. R5 c3 V: i2 b: N/ A

- I- U. I/ A! i+ X  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ ^2 R& {! [8 R% [" F! X
  set acceleration 0.0996 s6 L8 z- u! R5 A8 c+ M( }- P
end- D, t0 T1 x$ u' X9 v+ t$ ]
% V. N5 B7 A! [+ D
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 v& \, s+ ~1 q
;; and initialize the traffic lights to one setting- T: m; V* n8 \
to setup-patches
4 D3 y4 k$ n+ b: H, f: O  ;; initialize the patch-owned variables and color the patches to a base-color4 q$ v" c4 ]8 |$ F: c; n  Y+ B
  ask patches
. c' [% b+ l/ k  [( N: D$ R! u! i3 j$ J7 E
    set intersection? false
2 j' N; p/ e! O/ \' B2 ^& }5 Y    set auto? false
5 {( s) X' X/ C" k# B    set green-light-up? true7 n7 m7 }& w7 F: M4 F7 x
    set my-row -1; k! V+ v3 [% B) I/ r4 Q  x
    set my-column -14 W: Z" |  d1 Z$ G3 O' i. g
    set my-phase -1
# J5 X3 N3 C) r5 \    set pcolor brown + 3$ G  @3 r( k7 h, B. I& [
  ]
( M4 n' p. b( l0 _' @+ f4 R' h! i
2 s5 b' Z: U5 D; q4 t5 C6 s  ;; initialize the global variables that hold patch agentsets3 ^6 W2 w: h9 e# L2 k
  set roads patches with: u5 Q5 A  n" l" {2 \
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 }  s: V: Z3 W; l7 l
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 e+ k" b1 ^) s* G" @7 d" [  set intersections roads with9 d9 j9 n( r+ \8 l
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ H* d4 A  n, H3 P1 h    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* Y. @' c9 t( h/ c! q: j) X! Y
; h1 j1 b& n: q4 y+ m7 F) F
  ask roads [ set pcolor white ]1 G8 J4 N# V& X& K
    setup-intersections
" }- k. m' S; s/ p9 k  Qend: Q- H7 @4 }5 E9 S  C
其中定义道路的句子,如下所示,是什么意思啊?1 D2 @, r3 d; R- r! ]0 ?% t1 ~
set roads patches with
* n6 H' h  j* T6 u    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 A0 H3 p! I; ~. z* u) X% g    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& `" B$ ?; c$ V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, 2026-5-22 02:31 , Processed in 0.021908 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