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: 11287|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 W: z9 V- f1 d: D2 q7 `, enetlogo自带的social science--traffic grid这一例子当中,7 ^, V' G6 [1 R
globals
. x. J4 j9 Q4 D% E[; }8 V. N: U1 ?6 C5 {- v
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
+ C' F' u- O. {: u8 s: a  grid-y-inc               ;; the amount of patches in between two roads in the y direction  ]+ H3 k+ H$ ^/ _
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if, S7 q9 W7 P0 p) u+ [
                           ;; it is to accelerate or decelerate
' L$ J9 J* j+ m" D6 r2 B  phase                    ;; keeps track of the phase- B4 I( o# t: y  X3 R5 J; E, `
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
9 N7 k( s; }/ w& U0 S  current-light            ;; the currently selected light
6 L- P% k1 }- G) R3 I' ?3 X& Y6 d9 X
* j7 }2 j+ e% R0 x  K9 G1 D  ;; patch agentsets& A/ X% ]8 _; T. q, U" ~9 P
  intersections ;; agentset containing the patches that are intersections: `+ x9 P# p5 s. i2 R
  roads         ;; agentset containing the patches that are roads% \* T( Y8 ]9 A6 M
]# ?4 G0 |7 }% S. q1 F8 l. {- t" O
( G0 S( n; g" m8 N, L) O) t
turtles-own3 {+ H9 x- k& j7 W
[
' L2 [' e. |. W$ D& o  speed     ;; the speed of the turtle& K4 k: G* I. C+ [1 Q
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
$ @  w) r0 C6 a5 d) p6 f+ Q  wait-time ;; the amount of time since the last time a turtle has moved+ f9 W! Y( o5 U) Z
]# ]1 I1 x+ p+ n: _/ t/ r' x( ~
  `* p2 u; |  M/ B% Z
patches-own4 _, |$ N  Z0 j/ k9 S
[
1 L, }- p  I3 Y. u  intersection?   ;; true if the patch is at the intersection of two roads) {) l" N% [8 \9 Q- p* }  T3 _
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
) u% j# T6 X  |$ `                  ;; false for a non-intersection patches.
9 I5 v* b/ |- M. S  my-row          ;; the row of the intersection counting from the upper left corner of the$ r: A$ q' `/ q
                  ;; world.  -1 for non-intersection patches.
: Z% L! x. N' ]; g# g0 w( i  my-column       ;; the column of the intersection counting from the upper left corner of the3 F3 D, T) M; `* E# P
                  ;; world.  -1 for non-intersection patches.% w: p* i& @; O$ P
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.3 Z2 K# M  S: s" f
  auto?           ;; whether or not this intersection will switch automatically.
6 B& \- [$ @7 b  Y8 k5 M                  ;; false for non-intersection patches.' G, e0 e2 S) B0 [8 ?
]
! i" Q( f, z9 |$ q$ U: s% ~! N8 X4 B1 N; t

6 l! l; \6 B7 Z8 u8 J;;;;;;;;;;;;;;;;;;;;;;
: d  E8 J0 S  j9 o- X$ u7 y/ |6 K;; Setup Procedures ;;
. y# n" l: `4 G, G0 G/ n;;;;;;;;;;;;;;;;;;;;;;
4 W1 a- f/ w4 C; {
1 y2 x, f4 v. B% G- S7 U;; Initialize the display by giving the global and patch variables initial values.
5 c, Q% ?6 k7 N2 D;; Create num-cars of turtles if there are enough road patches for one turtle to$ E' A, s" P  C/ g& M
;; be created per road patch. Set up the plots.# r7 Y4 U. x, L  e1 M
to setup9 |4 W8 E5 @- O8 k) s- x
  ca
. ~2 c- N! o8 t/ A. z  setup-globals
' e; X+ t5 t( M, F; s4 K$ s  h0 _0 w: C. z
  ;; First we ask the patches to draw themselves and set up a few variables) i! N: O* B0 x* B9 Z! T
  setup-patches
* {0 i" A4 \; I: s  make-current one-of intersections
4 `# h: P9 X1 [0 ^  b  label-current& X# s/ d; j1 R

( q9 h6 |" W" _3 ~5 A  set-default-shape turtles "car"
. @. a( ?: n4 @* t. j( L5 Y
" K. p/ `& q  c6 v- Z4 ?  if (num-cars > count roads)# `5 A7 T" g) p7 e0 f! o$ a
  [% f4 ]$ ^' Z5 m4 f" |" `9 v
    user-message (word "There are too many cars for the amount of "
- n% o9 M  b( `6 v                       "road.  Either increase the amount of roads "
% v1 u5 I# M' t3 g/ @, f; w. i& h6 ~                       "by increasing the GRID-SIZE-X or "
, H; m" p: J+ B) o6 g& o; }                       "GRID-SIZE-Y sliders, or decrease the "! [; ^$ e4 W4 p4 o) ~
                       "number of cars by lowering the NUMBER slider.\n"
4 l& l4 T3 U+ U                       "The setup has stopped.")9 q( J: j. C. c' [4 r
    stop6 z, G" v0 j2 V4 w
  ]) R/ V3 E+ u- ^% ]
% [6 C7 P6 K, V+ l  f, z' d
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color; v  M5 d: v5 a5 u- Z
  crt num-cars
8 M$ r/ I7 n" V6 s  [
8 Q+ V% O/ }$ r1 n: r    setup-cars
$ X2 C8 V% v7 {3 i& ]9 A, w    set-car-color
" H- Y0 C9 o" X( N& A    record-data
* r6 y* M! p1 r5 s# ]* s, N  ]
: t6 v6 O: W0 S  j& L" V
" `, \: N3 W1 c) v$ d9 O  ;; give the turtles an initial speed
( @7 l( J' y2 X3 k; I( N& [% o  ask turtles [ set-car-speed ], G4 b; k! f5 ], p1 E- h; A2 D
! f2 u$ y% \! M0 D. ~  j; ^3 x
  reset-ticks3 l. E5 c2 i2 t; Y0 @" {% T
end
+ h- @- m0 b; l/ f( I; J% G9 N. C0 z$ y; u" d/ e* L/ ?# I  n
;; Initialize the global variables to appropriate values
( G: w5 C* o3 Y# N8 K- Sto setup-globals. T  p# v0 a* S7 A. T
  set current-light nobody ;; just for now, since there are no lights yet& [8 g: k) Z) i! G& l
  set phase 0
' W  C6 H4 p/ \/ |$ E4 y- z5 P  set num-cars-stopped 0
9 [% c& B/ X" {' m+ g  set grid-x-inc world-width / grid-size-x
2 k% l( m: a: i+ g5 ]# ]1 h* U  set grid-y-inc world-height / grid-size-y
7 w4 Q/ V4 t8 T  g7 Q1 y7 _8 h2 c$ ]% E5 z' A
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary3 ?8 c2 i1 a6 ]7 ?2 X  i
  set acceleration 0.099
& ?% b7 k# W) j* `; E" iend
% D% p$ y( f% F; e2 ]$ ~5 w* L3 `- k7 d
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& O, b! z6 c: h1 h( ~. D5 z! V) h) ?;; and initialize the traffic lights to one setting( l1 j+ O, ?# l1 L, `0 w
to setup-patches7 \: R# c6 X4 w. m4 M
  ;; initialize the patch-owned variables and color the patches to a base-color
* Y8 ]8 s" Q+ J  ask patches$ Y& J, L3 q7 v" }5 r  l" _9 U
  [
9 n9 y# Z7 M* y: h    set intersection? false8 S( p9 l4 w  s8 V. Q
    set auto? false
' z. G' j# j# S    set green-light-up? true
, X4 H: a; {9 a( C    set my-row -19 I" z, r3 b' w7 n0 f* t
    set my-column -16 C2 z! @0 T* Q& E3 O
    set my-phase -1. Z* h: \: o& P% N4 O
    set pcolor brown + 3" d) s& _$ q8 |' z  h
  ]
' t* p4 B. c" A  K0 a
" z# {4 r) C0 H$ V4 v  ;; initialize the global variables that hold patch agentsets
+ X  S2 {2 K, i) {  set roads patches with
( U3 T* I8 k. q! p' i' I    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" ~5 x( G! v  \    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( L6 _' y5 g2 k: L& d  set intersections roads with9 H, o6 L9 @' Q& `) Q' o3 Q
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 o1 o$ o& d2 o  p' l! }4 B% l    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 B4 ^6 H- ^5 l. F' {" R
0 M' b$ `8 _/ B& ]1 R$ Q  I6 h
  ask roads [ set pcolor white ]+ x9 B4 t' Q  e, ^
    setup-intersections! J' T. K8 x0 |2 J& q4 s3 O: E
end, |9 Q1 q. }- ^0 Y  D) z4 t+ H
其中定义道路的句子,如下所示,是什么意思啊?
! Z) t5 ?: r) H9 P4 T set roads patches with
- m3 u$ I3 _4 `; m- O5 y" n/ Q    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% J2 T4 @% J* D+ Q
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 N1 n& Q: E6 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, 2026-7-23 14:28 , Processed in 0.013324 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