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: 7634|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。: O+ ^' U" c2 x& ~$ x/ q) q
netlogo自带的social science--traffic grid这一例子当中,
8 V! x( M: h# u4 |8 c# a3 Sglobals7 H  X! t! _5 K1 N1 ]
[
9 |+ G6 q8 z5 z5 i" O" {  grid-x-inc               ;; the amount of patches in between two roads in the x direction8 g$ P# H' K7 j4 R+ h3 G3 v
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
  G8 c# Z+ k8 W+ M/ n+ m  acceleration             ;; the constant that controls how much a car speeds up or slows down by if) `; N/ \" O! Q9 L
                           ;; it is to accelerate or decelerate
- o; F5 L+ t7 P1 p  phase                    ;; keeps track of the phase- Y5 R( c  Q1 @
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure+ Q" s5 V9 W2 S: E( S
  current-light            ;; the currently selected light/ M# @% L! |0 y, i# D/ v; [& L. w
8 v2 E# v9 D" v) F; H* V* N# G
  ;; patch agentsets
  h% {6 D! S8 h7 F7 |/ }- B  intersections ;; agentset containing the patches that are intersections& V! Y  I2 m1 I8 D
  roads         ;; agentset containing the patches that are roads
! i' v, z! P# P% x]
+ t$ M7 u2 s  s9 [& f5 a: G9 F, N# ]6 r- }
turtles-own
0 f8 h) O$ S" z# T/ X  X' {[
! ~1 I3 g, F$ U. e2 o  speed     ;; the speed of the turtle2 D- t& i) G# t
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
' q( c/ h4 Y+ {# e  wait-time ;; the amount of time since the last time a turtle has moved
% @; g+ g: p- |( Q3 P3 P]* \* v/ X/ r: s" M& ~
, l4 o. K! t' Y  U
patches-own/ @4 @7 D# ?/ R4 E' O- s
[- l* K! u1 I3 W2 {! R0 e
  intersection?   ;; true if the patch is at the intersection of two roads
  s! v7 ], P! q+ d6 L2 M  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.5 M7 Z1 D$ x3 k2 C5 ~- r) ]5 ?
                  ;; false for a non-intersection patches.
% Z" J, @! u' Z7 K  my-row          ;; the row of the intersection counting from the upper left corner of the
2 T$ E9 U/ l5 c, o7 o                  ;; world.  -1 for non-intersection patches.
6 p& p$ [0 z  Z4 ~) k1 c" W; t  my-column       ;; the column of the intersection counting from the upper left corner of the5 x, s0 E2 [7 F7 m( @# O
                  ;; world.  -1 for non-intersection patches.
4 a7 z3 N6 `) [. H4 v+ g  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
( P" E2 ~, o" A6 x0 B  auto?           ;; whether or not this intersection will switch automatically.) W6 \8 ~# o* S( U) v6 H
                  ;; false for non-intersection patches.( ~- k; g8 w$ R$ ]% A8 z. o4 {
]. t" E% J: S8 M( r

5 d6 r3 p6 a3 A5 L  n
' n' A3 U$ D9 s+ D;;;;;;;;;;;;;;;;;;;;;;7 I4 f% K; F. s0 S" x
;; Setup Procedures ;;  J5 K7 s0 m% k  \6 f; \
;;;;;;;;;;;;;;;;;;;;;;7 ~6 C- H9 ~& H" z9 n. s

4 z; B+ T$ D$ \8 b;; Initialize the display by giving the global and patch variables initial values.
* W: n) c, b3 M5 y' Z/ z5 m! \;; Create num-cars of turtles if there are enough road patches for one turtle to
6 ]5 F: {2 H- i" {! };; be created per road patch. Set up the plots.
" V$ H, M3 w0 a6 qto setup2 |8 A4 |. w1 \6 u6 H" J. x
  ca  H1 g' H4 }: u
  setup-globals, ]& l. d! ?0 q

8 l# b+ D4 J% T1 b2 N3 D  ;; First we ask the patches to draw themselves and set up a few variables
0 j; o/ E5 M) ?) x3 B1 e/ ^  setup-patches
, L% g# e( e% q- U- c' S, Z  make-current one-of intersections
6 k8 b; x/ h9 r8 C' g) h  label-current$ ~  E6 @4 ]! Q- ]* ]2 G

8 c: B, u' @7 t3 \  set-default-shape turtles "car"
) j8 k+ k* L* a9 y6 R# |) i- p1 d" `# s4 |
  if (num-cars > count roads)0 a/ c5 [% C: P6 B% f
  [1 }6 @, \' f( ~- t  `7 `  Z! K5 i4 ?
    user-message (word "There are too many cars for the amount of "
0 O* n* N; {6 z+ j% T; B                       "road.  Either increase the amount of roads "! y) e" N! z/ V& ^1 ?& ~3 N
                       "by increasing the GRID-SIZE-X or "
! u$ F* J& ~6 W: k! P% Z& R                       "GRID-SIZE-Y sliders, or decrease the "
0 q6 }" e- N6 y& O! v                       "number of cars by lowering the NUMBER slider.\n"- ], S7 v) h. l
                       "The setup has stopped."), T0 j3 B2 U8 N' p; M# ?- d
    stop, n% ^9 g4 D! w- m1 @# r
  ]' q5 n9 \' U4 ?9 ~- E# V# K
) Y8 `  w, ?5 v# h6 M
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# T8 l1 k- f5 q* j# g% I
  crt num-cars- h1 Q- O. \+ p5 f& z
  [
5 ~* a* X% {& R. O4 j    setup-cars
/ n. d2 M: v" b3 A    set-car-color
0 M5 m$ D- `4 C& p; ]/ V3 p/ M( R6 ?    record-data
; E* _6 T5 G0 n0 Z/ E  ]6 m4 I9 v9 Y1 X# s( e4 W+ Y
$ M, p1 Z$ o* ^' E' E1 F
  ;; give the turtles an initial speed
1 B6 Y) T: W7 ?# v, r5 a/ Y  ask turtles [ set-car-speed ]
; A: i; h, X$ y# U/ Q* L' `" {  @7 h- h/ q2 K0 e, T) w
  reset-ticks8 k! g; R: i3 a) f# T! n+ U
end3 |8 P* }6 R) L/ x+ |

8 ], Q% T% i& [$ P6 ?4 S7 Q4 \;; Initialize the global variables to appropriate values
  ]4 e& g9 r; N& f' \to setup-globals
' J! e0 T) p- s0 \7 o" S  set current-light nobody ;; just for now, since there are no lights yet) ~" }( j3 U2 m$ g0 O( u: a
  set phase 0: T! K) d/ F; U
  set num-cars-stopped 0
% b1 Q( z" [, ~# C$ D: ~# Z$ m0 j/ {  set grid-x-inc world-width / grid-size-x0 z, U6 m* f  g" x' t/ u' o. ~
  set grid-y-inc world-height / grid-size-y2 n: s  u( Y; m6 e. H

; c" W$ E2 z+ |8 T$ b1 L/ S  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! x# X6 O: `- |. X" |5 F  set acceleration 0.0990 u8 w; X8 z3 \7 Z1 D
end
  U$ W, z- Q% @" h
9 d  s- {3 ?( N& L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( H5 g: f9 w% T
;; and initialize the traffic lights to one setting
3 K( @: ^$ s) @% ]5 M3 nto setup-patches# t! c' P6 L) E9 e5 Q
  ;; initialize the patch-owned variables and color the patches to a base-color+ h6 i* l& K7 s4 L
  ask patches+ g6 c9 A- A, w$ {
  [$ r; v* e9 f3 v8 p1 n0 r6 l5 O
    set intersection? false, V! _+ i  `3 q3 I
    set auto? false
) r, j  _! K% V3 o7 S. h    set green-light-up? true
; s; m, U( ]) T    set my-row -1
1 _" L4 A- _* ]$ \& v: o* X* W    set my-column -18 U* V) i6 Q5 d) U4 _. I
    set my-phase -1
2 e6 P$ G. L) y/ \- P9 k    set pcolor brown + 3  p* \$ O8 I" Q( t) z1 u( k
  ]: d6 Y6 A9 o: j  B

1 S5 v. }0 S/ j9 `' b8 L  ;; initialize the global variables that hold patch agentsets
  \! {; ~1 b1 L+ ^' _6 P. t  set roads patches with# R5 m1 w4 @" v- E4 F/ C, e% d1 b1 Y! v
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 h4 i2 X  @; t    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 e1 L6 Q" r0 m  set intersections roads with
& T. n3 M; ?. Z; x9 z    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ c# g! b: @* m    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 k; v. V* s* U! G) w# [8 r( i4 ~. S6 N6 G* P/ [4 e
  ask roads [ set pcolor white ]( L4 A4 m! p) F" ?4 @
    setup-intersections
5 F+ \2 }. f) @7 ^end, z. ~9 ~& F+ d! R1 k; M2 ^' e
其中定义道路的句子,如下所示,是什么意思啊?/ ?% x4 N4 _$ j; c
set roads patches with8 M% I4 x+ S0 `$ |
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ `+ c; O; q+ G, f9 j% ]6 l2 i3 H- \
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ C0 V: o0 R2 ?6 K0 I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, 2026-1-1 05:08 , Processed in 0.021184 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