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: 9783|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。  r: C& a; S( C4 f
netlogo自带的social science--traffic grid这一例子当中,
9 Y5 F$ r. L  T' ?3 e" u1 bglobals! o+ ]# W$ z! O7 i! Z  p1 N1 p8 x
[
3 T- T2 J2 r; Z+ I" t  grid-x-inc               ;; the amount of patches in between two roads in the x direction8 C7 K8 d. d5 O$ E! }4 W
  grid-y-inc               ;; the amount of patches in between two roads in the y direction, d( d" h2 d6 R4 j2 y3 T
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if# F/ g, F) E6 \  M
                           ;; it is to accelerate or decelerate
" x7 W# z* J' n$ I5 J8 T0 V2 S( w  phase                    ;; keeps track of the phase
  Q0 Y$ E0 @* _) q- ]* w! k  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure+ |) k9 ~  d, C) |# s' p
  current-light            ;; the currently selected light% x2 b" l# [8 u$ D" A- Z/ |) g

8 L+ x6 I, s7 c* ]: P4 |* s6 G  ;; patch agentsets0 a+ |! ^7 t* v: ?7 x- ~
  intersections ;; agentset containing the patches that are intersections
* p$ `5 Q$ q! }9 K% k, |  roads         ;; agentset containing the patches that are roads
: l9 N( c5 j* \, u/ n% ]]
& q, I+ z9 v9 r) j1 `: {
6 ?" p/ t4 k) Y; c/ ~) ], Nturtles-own
: A) a" c6 Z) J4 t$ _[% F" f3 z" q0 D4 J, P. \2 D
  speed     ;; the speed of the turtle, e) N/ c' [7 O2 x
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right. [; ^" N# i+ H' Y; Q
  wait-time ;; the amount of time since the last time a turtle has moved
  u/ J: I9 J9 r, Z: Q]
6 g$ y; r5 {. w0 H2 O& M$ G4 G3 C6 k
patches-own, w" Z$ T) I) [! `3 e1 d1 w
[
. G7 O8 k: J- H# ]0 l6 l; D$ p  intersection?   ;; true if the patch is at the intersection of two roads
; O1 K5 }: m) t. ^! G% w0 m6 S  ~  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
' H2 G6 R8 g% R7 a+ B- q# L                  ;; false for a non-intersection patches.  R/ Y& q. a* g+ ]4 G
  my-row          ;; the row of the intersection counting from the upper left corner of the
! b5 f6 d7 Y' h9 D0 b5 F; i                  ;; world.  -1 for non-intersection patches.+ x+ H& D" \" \7 g
  my-column       ;; the column of the intersection counting from the upper left corner of the
& c. Y$ W) W7 m7 z" H" ]' J9 ]                  ;; world.  -1 for non-intersection patches.4 L7 D2 ~/ i1 x* ~( c% J
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
$ C0 }& ~1 X3 X- u) D# z  auto?           ;; whether or not this intersection will switch automatically.
: ^( e/ P2 z2 k9 _: }                  ;; false for non-intersection patches.0 t- C+ I) `4 u2 s/ x5 r
]( i3 \' c: t8 h. ~1 G

* b) @' b6 H$ w! C& p
& o3 E$ h+ M4 Y" l# i;;;;;;;;;;;;;;;;;;;;;;
3 `2 _- L! |+ S9 {  A( r;; Setup Procedures ;;
! w# ]; T# z1 p+ Y0 ]' Z;;;;;;;;;;;;;;;;;;;;;;. A' v, N8 S* T! D& \

2 w1 b% l3 p8 Y& t2 Z* W;; Initialize the display by giving the global and patch variables initial values.
6 H7 @  e. p& v& {5 Z% L7 x;; Create num-cars of turtles if there are enough road patches for one turtle to6 a+ ~* D. \2 D; [0 r
;; be created per road patch. Set up the plots.# l8 s. F2 F+ b. C
to setup1 Y6 X% E$ ~8 u
  ca4 n8 |7 T0 p0 i
  setup-globals
; ]  E9 }& u/ }" S: \( j0 H8 p9 n: M- D: l5 y* q: x$ s
  ;; First we ask the patches to draw themselves and set up a few variables( \* ?: d1 X" t# `7 r! n4 g7 Y
  setup-patches& l2 `) l: ?4 `! I. y
  make-current one-of intersections# u- Y* Q4 I5 A2 v
  label-current
+ C' P- S9 w$ t0 j3 ]7 ^. {2 }
3 e4 W. t1 l4 z2 M6 I; U* n" \  set-default-shape turtles "car"
* u6 d) V* u+ |; p
& W# V7 i- h0 V. J) \# h  if (num-cars > count roads)+ L3 w  v( L: L; R& d* W
  [
% [0 B# _& P/ a6 ~    user-message (word "There are too many cars for the amount of "
2 M- r! M" Y4 c" f, y' l                       "road.  Either increase the amount of roads ": w9 d! h6 ]; e) \  p2 s* X  I
                       "by increasing the GRID-SIZE-X or "
: y8 B: X7 ^1 S" R3 ~& b( a                       "GRID-SIZE-Y sliders, or decrease the "% P( R8 d; j- D) d- ^
                       "number of cars by lowering the NUMBER slider.\n"; j0 Z1 D* Y1 p
                       "The setup has stopped.")
4 h! C3 R4 d+ u4 h, X    stop7 s" V) `  `2 ^3 M9 L
  ]* [) b$ u6 }: ^& B7 I: r, [
! j. L4 u' Z" O
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: x$ a  S. d+ |( Z  D  c  crt num-cars- `8 c3 r  U% q" v& X* q
  [. U$ N/ f! \5 |5 B
    setup-cars
0 A* _: r; k- S, V, R    set-car-color
+ ~6 b1 e- f- D3 X9 j5 q    record-data
# y  b& K/ x% U* P' Y* ~2 s; u3 W3 T  ]2 A* v9 h) T, Y) R) g

0 D+ c; y: z% r! o+ V/ O  ;; give the turtles an initial speed
: O% d  r" {2 V& F+ q& V: j  ask turtles [ set-car-speed ]/ a9 ]- ?9 B& I0 }( E& O
- m: x1 }* G  k, j, Z4 o0 `! |
  reset-ticks
' q% Q& \  o7 \% L* E) ]end: ~+ N# {7 y; s5 {- r/ P* \
5 \; ]" G0 u+ b1 H9 q
;; Initialize the global variables to appropriate values
2 q2 S/ q: }: D% R! Hto setup-globals
! v2 v  N- }) J! q$ \' u  set current-light nobody ;; just for now, since there are no lights yet
2 M" w' s$ V% S0 y5 A1 ~  set phase 0
9 [7 U, y0 P8 ^% a5 z. G# L# Z  set num-cars-stopped 0
9 o2 r0 x6 s$ Y  set grid-x-inc world-width / grid-size-x* ^/ K$ ?/ K. }9 u
  set grid-y-inc world-height / grid-size-y( w- l0 a' F: i* A  i; ^/ W

/ M  Y3 `  c% Z/ e; x" ]  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% Q9 I1 O" P: V; Z! f0 S0 M. i  set acceleration 0.0991 d! ~8 r8 t+ \( B" b- F
end6 T7 Q; o. I" X* `
0 V3 c+ o( [5 F3 U
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 v* g2 k. q3 c; z1 U6 r$ m* j
;; and initialize the traffic lights to one setting  M" P8 N" y3 q$ f' c+ s9 t' e' ~
to setup-patches
4 N) ?% D2 [0 i  ;; initialize the patch-owned variables and color the patches to a base-color/ R5 `! R3 t& t0 J
  ask patches1 E5 E: E( ~4 h+ }# `4 }* B
  [9 D4 F8 t1 `" A0 u: H
    set intersection? false2 n+ T. b3 ~$ P6 i$ U3 g4 P
    set auto? false
( [0 L6 k; J7 d; W; v! W& Z) ~    set green-light-up? true
# K8 A4 m; O2 G# W    set my-row -1. S- }% v7 {/ \4 J0 W  h' V
    set my-column -15 s0 U! D3 q- N# D% ~" T8 D
    set my-phase -1! v4 z4 t( \" ~
    set pcolor brown + 3; F  X( @4 J" y! y8 ?
  ]
3 f1 u1 B5 N: C% t6 c
9 Y  t' f0 F$ z9 X( ~  ;; initialize the global variables that hold patch agentsets
# G) w4 T8 I( j% ~  set roads patches with
. v* L$ L) y6 x' I9 t3 w% u' u    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& s: d- J6 T# p5 H, J1 k    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! x( q5 c' C; D; K
  set intersections roads with
- ^$ j8 C: W' v" \& u, v    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' i( o: A% Q5 W7 u1 G    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& O* G5 D" U4 f' k, G% D* N8 `* i7 _$ \/ }# v2 k! V& w& H
  ask roads [ set pcolor white ]& ^- E% e5 e( w; w- x! T- F9 Q
    setup-intersections
- L1 r( c+ }, h! }* X# @( T# [end7 a: F5 n' q! r+ d) G
其中定义道路的句子,如下所示,是什么意思啊?7 v. w. J. u4 F$ }, @
set roads patches with
8 M, G! U8 p6 g! k5 Y; v# M    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 y: g! d% Y) P, n: v2 M+ K# V
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' s# {' G. W2 `! C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, 2026-4-30 19:32 , Processed in 0.017568 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