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: 10934|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。
: V* V- ^. B5 S4 m7 Anetlogo自带的social science--traffic grid这一例子当中,
8 ~" o0 N4 X( Z" O4 \7 v* Jglobals
* U) ?4 J* U- D; s, Q& `$ N[
! l* {3 |( l( X4 O9 o, _6 T  grid-x-inc               ;; the amount of patches in between two roads in the x direction
% T4 P  @+ h" K$ D* [6 I  grid-y-inc               ;; the amount of patches in between two roads in the y direction# z& \) L! [* f$ V6 f
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if- c" E9 q/ j# F  h& I: ^
                           ;; it is to accelerate or decelerate
- p* F+ n" C# s! m5 J4 J3 b% A  phase                    ;; keeps track of the phase
+ Y1 h- k  j& j, }  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
  |% z7 q& u6 l- Y' |! V  current-light            ;; the currently selected light  ?) u9 \) E9 h" ]# v6 T8 i
/ v) ^# y! r# B# l: k
  ;; patch agentsets% }; B4 x2 Y& @: m: L0 r4 [# C
  intersections ;; agentset containing the patches that are intersections( U* T# K, I6 y7 f
  roads         ;; agentset containing the patches that are roads
( ~) y: E" q: r) }& W$ l]
& z$ V4 o- K* V* m2 o4 N( o8 v) w
turtles-own
# R+ O( f. J4 R9 _% J% a[. d  }  J4 a; K! K( P9 b$ U
  speed     ;; the speed of the turtle
8 B6 V' W# y2 R" W6 R8 q8 o  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
/ p: l) q( `" t% f( V  wait-time ;; the amount of time since the last time a turtle has moved  q& B7 [; ?6 d! H# L
]  C! U6 I7 k# E7 S
! ]& t& k2 Z/ W" b" ^! A9 C
patches-own* S! Z. c8 T% @  i+ U  B# A0 W9 p
[
, D9 K) [% ?; Q1 ]- c  intersection?   ;; true if the patch is at the intersection of two roads
6 g; t1 n; t+ H  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.  [; G: k6 M" e3 E* \
                  ;; false for a non-intersection patches.
% v- F1 P) j2 ~  w! ^2 \  my-row          ;; the row of the intersection counting from the upper left corner of the% D! E& q4 p/ p, ]5 {4 w% G
                  ;; world.  -1 for non-intersection patches.8 V# _; t  y! x( w! E5 H  c
  my-column       ;; the column of the intersection counting from the upper left corner of the
# ]0 F3 w4 y4 I! J                  ;; world.  -1 for non-intersection patches.+ o* a. @8 z  r
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches." Z: ~/ ]/ ]$ \, J. y; w; G5 P/ ~
  auto?           ;; whether or not this intersection will switch automatically.9 G- \5 ^0 K# e2 y1 \9 {3 Y
                  ;; false for non-intersection patches.
/ P$ h* Z/ _( p]
$ ^  v5 W6 v2 l  U! |! j' ]3 I- k: K( n; k: @0 ]1 H

/ K: y: J# w" S7 N/ o;;;;;;;;;;;;;;;;;;;;;;
" c' B6 Z2 b( J8 Z! X9 G;; Setup Procedures ;;* @2 P  N4 _1 k3 K
;;;;;;;;;;;;;;;;;;;;;;) X$ G. ^: O+ W0 f

8 j+ ?' u. Q; n3 T  r;; Initialize the display by giving the global and patch variables initial values.
  w* M. x" R4 o;; Create num-cars of turtles if there are enough road patches for one turtle to6 W8 o8 I  Y4 o3 ^
;; be created per road patch. Set up the plots., G( H& c6 V! z7 V/ \
to setup
& J+ m) l4 u$ j/ D* w  ca
5 x- f; I3 |) I/ S$ L% ^  setup-globals* [( P+ F1 z" s$ \0 _- }4 E
, D. x1 h; r) e) \8 z
  ;; First we ask the patches to draw themselves and set up a few variables+ L8 S7 t* s- O
  setup-patches
# [5 ]0 n" v5 G  make-current one-of intersections
9 C2 a* P# F2 W1 S  label-current. `9 y' J, ^. A% Y
7 j! a( v  B+ r. K( E
  set-default-shape turtles "car"1 p- h: [1 r# y# f, S4 A, ?
7 d* m5 `/ d" S& e
  if (num-cars > count roads)
& R; E$ e* v  O- d2 w- L3 g3 U3 X  [
8 ]& P. E; @. T/ b; u5 j    user-message (word "There are too many cars for the amount of "
! {! y" X* z6 A# Y7 V+ e' K: N                       "road.  Either increase the amount of roads "
0 v% n6 f. u% Z                       "by increasing the GRID-SIZE-X or "
- C, U! o2 t: U2 J! B$ R7 ^                       "GRID-SIZE-Y sliders, or decrease the ". l' B4 B+ {: y4 t/ C5 A
                       "number of cars by lowering the NUMBER slider.\n"7 D9 f9 T- ^. M* L; R( d) w2 q( f
                       "The setup has stopped.")- \, M2 m1 W" o( T) D  S% B  Z0 v
    stop5 ^9 @! Y& ]6 ^# F
  ]0 B: ^$ x8 V& ?& ^; g
3 I" p" \: C* J8 J- }0 F$ B/ N2 [
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
  `: U, N6 \$ P% m' A) [  crt num-cars" W* g3 O' A, y  v
  [9 u9 q8 g+ {# d% s# d! B
    setup-cars
% e8 Q- F: j, ]) Z6 n    set-car-color6 L% [1 h% e1 K3 @8 r, I+ ^' [
    record-data# J6 A3 f. C" [& h" f0 X0 o
  ]
: y1 R* R8 m$ k2 X8 d
  u! i6 K  R6 P# W  ;; give the turtles an initial speed
5 @4 g7 m% u2 H" p$ S/ V  ask turtles [ set-car-speed ]
, X( G- _  |& M7 J' Z6 v8 L3 u5 v7 s+ v+ O
/ J6 h0 o8 d4 V4 \  reset-ticks  q3 w& U$ E5 _/ J. E) K8 R3 S
end6 @* s0 \& t  Q6 @5 @

6 q0 _; D( o6 _% O9 N: \, D# a0 J;; Initialize the global variables to appropriate values
; t! `5 J. m: y; F, e% h3 g& R- `to setup-globals
/ O5 Q9 a& i& G, c* S4 T  set current-light nobody ;; just for now, since there are no lights yet
- T6 a9 L' k# G+ x% @" z  set phase 0
. A/ W) b5 ^9 ~  set num-cars-stopped 0
4 T+ b% S+ v. B' J  set grid-x-inc world-width / grid-size-x# c& ^6 f1 A' E1 l! U
  set grid-y-inc world-height / grid-size-y
) D: [3 [7 M4 b) k. I/ q& M, M7 d- G. c
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' {( A* O, D; Q& z. z$ s  set acceleration 0.099
2 p5 i' n: U! Lend
% W4 t1 C- k. l
& a: J6 q: {% @: {) z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ Z& ?& n2 n9 b0 a1 ^$ _' H;; and initialize the traffic lights to one setting
# k1 |/ b+ n5 g& B3 [6 D* zto setup-patches# m# o3 X+ e& Z# `  Z& B9 G) h7 b" D
  ;; initialize the patch-owned variables and color the patches to a base-color
$ _$ C& ?& W1 V7 M, b* {  ask patches
8 A( B8 Y+ B7 b  [
4 r9 e3 l7 S# [/ I    set intersection? false$ ?3 i' c9 b$ b$ t
    set auto? false- G4 R4 {1 |0 d5 x
    set green-light-up? true
5 d9 l; N) B1 U" K  G. o    set my-row -1' c) q; {' ~, |; }' ~, \  s
    set my-column -1
* Q4 X5 k0 S5 Q* D( z    set my-phase -1% P4 S* c6 x0 v
    set pcolor brown + 31 c- E) y0 j8 A8 _9 r
  ]$ `0 [  h1 Q. s& o+ _0 l: W

$ E3 b5 [$ A0 M* G  ;; initialize the global variables that hold patch agentsets
) V% h/ H" u  R( H5 E5 a  set roads patches with
' _- a* a6 j" L# ?7 R9 F9 Y6 [& F    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 E/ O9 _' D* l3 ?5 d: x" d
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 s/ s1 J; T6 L% H3 }
  set intersections roads with
& i% a! D: q2 `    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and$ k* W0 ^6 C# H2 ~
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]  @4 A" `9 t, R: N2 r" J
! d  _$ }: g* D/ S, F
  ask roads [ set pcolor white ]9 L. }$ q# v% p# a/ a5 m3 @/ Q
    setup-intersections- y, U, b/ [8 A8 P
end/ [5 p' T  ~$ h6 n: r  M
其中定义道路的句子,如下所示,是什么意思啊?2 `. ?5 A/ `8 B+ N6 J' B, J6 O4 B
set roads patches with( b! h! c  v3 U" f- @' e
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
  L7 ?9 T9 v  O! \/ V8 S6 e# ?3 s    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; |7 T, v9 t* ]1 m! a
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, 2026-7-5 08:42 , Processed in 0.014874 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