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: 8137|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。
* y0 t. l& B; W- W; t) Y: F8 p1 @netlogo自带的social science--traffic grid这一例子当中,2 p! q% ?" S  `1 U$ E1 b
globals7 M" I" y2 I# H1 [* N
[: l* o, w' ?5 w6 S" z/ k
  grid-x-inc               ;; the amount of patches in between two roads in the x direction+ I. k3 B1 x1 ?& ?# |
  grid-y-inc               ;; the amount of patches in between two roads in the y direction" [) o# b$ K6 U2 X; f
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if0 e& @: K) c6 |
                           ;; it is to accelerate or decelerate; d3 e$ y& l/ H* J; T
  phase                    ;; keeps track of the phase' J8 W6 f6 Y; |7 t
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure# o" }0 E; Z$ Z$ j; j# }; N# ]
  current-light            ;; the currently selected light& `; E# o9 l1 z
% u0 U" i( P8 W+ V
  ;; patch agentsets
" _1 `' O: G/ T) j: o8 N& D% D  intersections ;; agentset containing the patches that are intersections
. N& V; \& U' E; j8 z9 o: r  roads         ;; agentset containing the patches that are roads: l7 I1 ^+ d/ U6 l) O4 {+ [. X2 f
]
! Y4 H; T% b. E$ ^3 G3 x$ w4 B8 i) I8 E5 P0 F' F
turtles-own
$ R* T' @" l6 k# {8 y: [  \[
/ g5 i5 x: a& z1 C- }  speed     ;; the speed of the turtle/ t1 J& b; m% T  U( b7 {
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
4 m4 M3 }! O& n. j3 Z  wait-time ;; the amount of time since the last time a turtle has moved- y4 k( F$ A7 D
]
, g# A* h0 ?; S' _0 @8 J' F; T4 x
patches-own" _) f, E4 S% }, J
[+ K! O4 Y* W' `% g/ X0 C/ E/ C
  intersection?   ;; true if the patch is at the intersection of two roads
7 l( t4 B+ E4 c3 o  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.6 c; P0 F5 v- Q8 ?( o5 b+ X
                  ;; false for a non-intersection patches.
4 L+ ]" `5 S' ^  my-row          ;; the row of the intersection counting from the upper left corner of the
4 w# W* w  z% h% S2 ?* w7 `                  ;; world.  -1 for non-intersection patches.
* ]2 W/ x/ G" W3 l& q  my-column       ;; the column of the intersection counting from the upper left corner of the4 S$ ?& l; D8 s7 n8 f! m) N, B
                  ;; world.  -1 for non-intersection patches.# V& Y1 Q. \) X! n' t
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
6 F7 ^& V+ H0 N2 E  auto?           ;; whether or not this intersection will switch automatically.8 Q8 ]1 j; z0 P: P- P
                  ;; false for non-intersection patches.
' N1 m8 P8 e  k$ Y. U( d8 k% u]( [* w3 m: g3 R: e7 Y2 r
* L3 w% m: Y) G' d1 a! j: F

( `# J2 u, a& @6 e; Q. W;;;;;;;;;;;;;;;;;;;;;;. _  t: H  W  N  K
;; Setup Procedures ;;
' ~) [. Q- p3 V: B7 |! B2 N;;;;;;;;;;;;;;;;;;;;;;* G% D4 }! _1 C

% t* W; d  \: G' k6 X;; Initialize the display by giving the global and patch variables initial values.
, @  ^/ j- T, E" c;; Create num-cars of turtles if there are enough road patches for one turtle to
/ Z, b) @2 t  x% s- \;; be created per road patch. Set up the plots.
! v9 {0 D, d: U7 `9 F! {to setup
2 U2 ?! T/ N5 U. g  ca# Z0 T+ D6 P+ P% p4 R% H8 g" h
  setup-globals
* J% ^- s* h, p- Y1 z4 m$ N+ l/ r6 Y$ N8 U% l5 g9 u2 `
  ;; First we ask the patches to draw themselves and set up a few variables
+ n! T2 d; D* j) v  setup-patches
8 @2 q8 `+ K8 }% O" M* W% G( G  make-current one-of intersections# @7 g* ^; X. R; _
  label-current
8 X* n/ F+ ^, G; M6 U2 k) R% R
  set-default-shape turtles "car"9 i* ]0 m) `- k+ [# ^% W
0 x3 e. Y1 b8 n' T7 |5 Y) g
  if (num-cars > count roads)
' O* f& k  s" ~/ K5 @0 {" R- o3 l1 ]  [
1 _$ f) F8 L2 e1 m    user-message (word "There are too many cars for the amount of "
- x/ l- H$ G: U; A$ P. d                       "road.  Either increase the amount of roads "
6 q8 o: _' n. N; ?: K. U; {                       "by increasing the GRID-SIZE-X or "5 ^! w/ m8 q, P6 l' w, @& `
                       "GRID-SIZE-Y sliders, or decrease the "; d; a; ^3 z2 [5 h; a6 S( X
                       "number of cars by lowering the NUMBER slider.\n"
2 P1 d4 E7 u' I+ g6 F2 `                       "The setup has stopped."); V. ]# n* f! U& I2 {
    stop
7 Q# R/ }/ m, D; u# F: G2 \  ]/ z, a4 {) b" z+ e
3 e! U2 Q! s, _
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ u- l. ?7 \; w1 H- f/ j8 j+ t  crt num-cars" \, \6 l& W3 |: i. U5 Z' d7 @+ J
  [& `  ?4 r. x- j& f: o  ?
    setup-cars$ i+ p  b8 }, `7 P. h. o, o0 h
    set-car-color) B8 _( v* n, u& R. \/ |3 E: I
    record-data, C8 B; X! D* E' e
  ]
2 [& o) u. h* ~7 T; J6 v
& N' T% U0 l  Y8 k9 `; \  ;; give the turtles an initial speed1 \! ?; W* \5 h1 o" _6 v
  ask turtles [ set-car-speed ]* ?- L3 D4 I# {* W
( @6 `$ ]8 r" J5 R/ I! Q( u9 E
  reset-ticks
! _! f4 J/ {" z: _8 ^: Oend
4 Z7 b3 C" L0 y- n/ u4 W* G  K% \& P* n( R1 ], n. \- ?. }6 Z7 ]
;; Initialize the global variables to appropriate values: C7 L' s) p: \6 }. o- u+ U6 \3 B
to setup-globals
9 c# z) O( m% p  set current-light nobody ;; just for now, since there are no lights yet
' G8 ^+ x" M. Q/ A  set phase 0
# G. G& G% V: F8 E1 j  set num-cars-stopped 0
$ {; Y: S: W% V% c9 Y( W. a' E  set grid-x-inc world-width / grid-size-x
! o. v. b( L5 X& A  set grid-y-inc world-height / grid-size-y* s: N& w2 h. ?  W6 a* t5 U$ n

, e9 y/ u1 h! Q3 Z! }& ^! }  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
( T) I" P2 l' [, X; b( D$ d  set acceleration 0.099
/ a. D: H, s' P' J+ X: C3 k) tend9 x- W$ J4 d) L' Q- d0 \2 Q
3 C/ ~- A- w. A3 b! s
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 V' N" `' i# F- a;; and initialize the traffic lights to one setting
# P0 X% v4 f2 ~! ]to setup-patches% D( z0 z+ r2 R. }  r
  ;; initialize the patch-owned variables and color the patches to a base-color
2 S* g! P1 d9 s" }7 e5 e  ask patches
5 [4 V. H8 [& s! S; c0 C2 ^# F  [5 z0 v, w: i8 n& t
    set intersection? false
& y- Y6 M7 w9 {! x    set auto? false2 i1 |9 m* B3 T. y# X; p, Q/ I: ]
    set green-light-up? true
7 R. s; y& L# j4 S    set my-row -14 E% l6 u, _  n
    set my-column -1. R' j9 Z6 |+ d& N
    set my-phase -12 f3 W$ e; P7 S/ I. k, ~" t
    set pcolor brown + 3
  ~" C0 G$ e& B+ b% v, W  ]
2 `3 G; u& a) w/ ^/ Y4 m# Q+ X* B6 k
" y  p% M% _: r, `! @/ `  ;; initialize the global variables that hold patch agentsets
1 ]; L# E3 V- [2 ~2 r  set roads patches with
7 }3 I) y% w- R- M4 n    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' w3 L: f% n+ R0 p% ~; p
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 y/ w  O6 b7 s. c: d  set intersections roads with. e4 k3 x' I( _6 V9 h
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 t& _1 m  v+ {% H0 H6 x    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( ^9 A2 |$ S% O# j: e: C2 ]* r2 `4 f$ r# r  g) \& v$ P( l
  ask roads [ set pcolor white ]
( V1 W6 V6 v& n* `6 Y    setup-intersections
4 b' n9 b2 K/ ^# x7 l# ?end2 p! E" V/ l' W3 W
其中定义道路的句子,如下所示,是什么意思啊?
- |9 q+ y" l  R) K set roads patches with3 f) h+ k. t9 h, A9 d( \* O1 C2 q
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& [, p9 c' @% t
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; C4 D' i( e, ?; I- l0 n9 ~6 P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, 2026-2-2 14:19 , Processed in 0.018868 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