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: 10809|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。
* T% C+ i4 F! k1 vnetlogo自带的social science--traffic grid这一例子当中,  Z- |  M& ~2 Y0 Y% S
globals9 y2 E" }  E5 m$ r' a! C
[3 Q- K: Z9 K+ J: z1 `0 Y
  grid-x-inc               ;; the amount of patches in between two roads in the x direction% e6 ^' G: p5 [, V: w  F6 v
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
" i2 \# I9 D) T: s- \& J/ v  acceleration             ;; the constant that controls how much a car speeds up or slows down by if! Z7 a4 n7 G7 x( z% s
                           ;; it is to accelerate or decelerate
# F  d, R3 d2 Y- Z$ n8 C/ A- d2 ~  phase                    ;; keeps track of the phase
0 h2 a) {% c- t/ j  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
" ~0 l  n% L9 S  V7 l/ q3 y& q  current-light            ;; the currently selected light. q& X; x& @0 H* a. U9 w, D
) D8 a& R$ Z" N$ m7 E
  ;; patch agentsets% o0 g+ a5 @4 u1 l$ V! ~; F
  intersections ;; agentset containing the patches that are intersections
& {5 \: f+ h5 h/ D1 ^* P  roads         ;; agentset containing the patches that are roads: M8 y+ I8 _0 \- ]$ ^/ J
]4 a  H3 I  a, u7 ]  c3 \8 C0 I

4 W8 s1 B# I! z2 qturtles-own
' i8 p3 Q! B7 }[5 N$ d9 {  p' K' Q% v5 M5 M
  speed     ;; the speed of the turtle
1 O8 b% A  u( Z! K5 M: e0 c- V  up-car?   ;; true if the turtle moves downwards and false if it moves to the right' o/ j3 i: S) {# c% i7 F1 V
  wait-time ;; the amount of time since the last time a turtle has moved
# O' Q$ y. q' \* Z( M]; w: u7 B4 l* g! I! ^- F& P7 F
5 Y5 e9 h5 s1 `) T. h# j/ }
patches-own
& d3 s" M3 O, Z3 U8 Q3 k- \[
& ?1 f, i' t! K/ L8 I3 ^  intersection?   ;; true if the patch is at the intersection of two roads
9 }% s! R* t0 M* R5 \) T% A+ h  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.3 k- m5 X3 _  U1 z( ~5 |
                  ;; false for a non-intersection patches.
3 P7 d/ G/ j$ L* C  my-row          ;; the row of the intersection counting from the upper left corner of the
7 w- y9 z* E" t, }                  ;; world.  -1 for non-intersection patches.8 R4 O& H- S, t  ]# G
  my-column       ;; the column of the intersection counting from the upper left corner of the
4 b  I! e3 f) O  j7 Y8 I  J6 z                  ;; world.  -1 for non-intersection patches.
/ ?& i- K2 D: x& y  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.3 p; B' p! l, {- q1 n3 e6 Z: @
  auto?           ;; whether or not this intersection will switch automatically.
0 D* @, f$ p; _; h' z                  ;; false for non-intersection patches.- {  M; {& o* ^( I- m5 J- L
]
, ?8 ]" {6 F2 Q
7 g( I) G. v9 x' w
. b; Z9 W! p: W" c7 |/ Q# e2 t;;;;;;;;;;;;;;;;;;;;;;5 U2 v5 s5 w( f  p1 q7 t
;; Setup Procedures ;;0 ?$ y1 T0 b1 G7 `
;;;;;;;;;;;;;;;;;;;;;;
: q1 c& z3 [# o" }: k4 a& }9 e9 \4 h$ O4 d6 e! d
;; Initialize the display by giving the global and patch variables initial values.
' n. Z/ g( r- [& Q! q  s;; Create num-cars of turtles if there are enough road patches for one turtle to
$ c9 X3 j1 X! ^;; be created per road patch. Set up the plots.
) B7 _! E4 L9 }# L2 \% Jto setup( _. o" a8 s! U0 v* _$ |" b' i
  ca5 G0 B' O1 M4 k* y# c
  setup-globals) _, V) A* T8 ~% m
/ w5 G8 Z0 g; k5 A; a6 L6 p! P
  ;; First we ask the patches to draw themselves and set up a few variables
7 L: z$ s$ N8 v. F# o) k  setup-patches
0 j% t/ j9 ^& S: ?3 r" r: ]  make-current one-of intersections
/ Q2 G$ P4 e- _7 q  label-current
4 j* e9 O" J/ A: M8 e2 n! r) D, n9 \7 d) B
  set-default-shape turtles "car"1 \* h2 T( `) J, y( x4 h1 V2 m2 N
$ W7 c! Y* @+ m) S9 @4 Y
  if (num-cars > count roads)- O7 z" x' Q7 I
  [
8 D; b6 }, P, [6 w4 z( t    user-message (word "There are too many cars for the amount of "
4 F6 D! ?+ H3 H                       "road.  Either increase the amount of roads "
( ^: }4 C" c+ d9 D! i                       "by increasing the GRID-SIZE-X or "
/ J+ N) t: \: B; c. ]                       "GRID-SIZE-Y sliders, or decrease the "
" w3 L8 @$ _2 x4 b' G! s# K$ V7 C                       "number of cars by lowering the NUMBER slider.\n"% h* u# A6 A2 j  d/ @$ L4 _9 g
                       "The setup has stopped.")
0 @/ ~' q9 l4 i. ?' K+ \. `    stop8 x3 R5 ]( v- o  H+ B5 U4 f- o' R
  ]! q; [) q: z% f6 |  ]+ k' M

7 V3 A% x: l; Q- [  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% n- m) Q7 {+ ~( P  crt num-cars
! P5 _& I& x- h+ l* M& @  [+ u& f6 q  a  ~
    setup-cars9 A0 r% @& \( Y; K9 Y+ G
    set-car-color5 L9 b* n6 w* g
    record-data
/ w7 U: j. ^2 Q1 l  ]
- T& @7 H( m, E9 A5 W7 X* {; S4 z. @; G# h( I4 j
  ;; give the turtles an initial speed
+ o" v& m# Q3 C' C) ]! I3 q7 C  ask turtles [ set-car-speed ]- K& O+ {, \3 Y5 C# p

- Z" g4 o, w2 Q. m$ j( H  reset-ticks* m' ?4 R- f! B4 Q) I
end9 [( ~5 g" {6 k7 ]1 R* a
$ j# p0 N/ v- s9 n8 q2 N
;; Initialize the global variables to appropriate values6 P$ L" }9 _; z( M: F
to setup-globals
" Y9 c! R7 W$ U5 q8 L' \: Q  set current-light nobody ;; just for now, since there are no lights yet
! i. |- a/ _( \' ~3 [  set phase 0/ C  h, w: q* ]  B4 w/ F
  set num-cars-stopped 0
# I: d' N. {2 S7 T% x$ Z, E+ F  set grid-x-inc world-width / grid-size-x
. L( `$ ~  Y% j* V/ c  set grid-y-inc world-height / grid-size-y- V& i) d5 F3 `- x3 K, E

1 r5 `- G' k# b  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! U) G0 W( O+ d/ M/ N
  set acceleration 0.099
9 S5 ~1 S6 g1 m- u5 b) }end# @, R/ ~" x  \

* W/ f  y* c2 ]) W;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 O5 f! \7 t' n* y" s. ~;; and initialize the traffic lights to one setting
5 g& z! C4 [) L( Ato setup-patches
) ]8 c4 \- t1 t/ Y8 Q: y  ;; initialize the patch-owned variables and color the patches to a base-color
/ D( }- D6 V! m$ w$ N0 x5 d9 L' s7 f( O: u  ask patches
; R" A" ?& Y' T% f" n  [$ A/ ?! b( U" }; e. r5 k
    set intersection? false
/ }  r' Z3 `: x! M+ \! `8 W    set auto? false
3 {. @+ ~) U) D+ ?    set green-light-up? true* x4 x* `7 [, k" d
    set my-row -1
4 O: S( q9 l2 F- a: `2 t" A    set my-column -1& P. d* c6 _/ L
    set my-phase -1/ W) j- w3 U9 W! P
    set pcolor brown + 3
: E/ Q- Y' e* X, G  e1 O. y- c8 [  ]% x9 x9 @, H) n4 O

( E/ \# `) q* @' P  ;; initialize the global variables that hold patch agentsets) T1 ^: P( U! b
  set roads patches with
6 g  Q/ E, f6 d7 a$ t( w( ]    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% c% z/ e. {. b2 B  \
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& N7 k1 q3 f4 _. N4 `2 v9 o  set intersections roads with! z, e, ~4 E9 u; a* l4 g/ A! T, b
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# q$ @# L. \. U# v" V
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, A1 n4 `+ _  i; C
4 h. i/ K- U  @$ g  ~0 b  ask roads [ set pcolor white ]; d6 ^% C; E' ~  l
    setup-intersections6 P; p1 c: e$ d0 C
end# J5 k8 @4 h! C; ]* C; t
其中定义道路的句子,如下所示,是什么意思啊?
4 q5 r% \6 a1 O* d) i) H set roads patches with
" `' _! ]. ~) b" M7 q$ u    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 r* M, A5 s+ s7 i$ B
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ D# K; w' I$ L7 ?9 ~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, 2026-6-27 03:19 , Processed in 0.014797 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