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: 9312|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。) p6 ^5 B) r1 S, ]
netlogo自带的social science--traffic grid这一例子当中,4 M8 P8 K4 H4 _7 O, c4 e& P
globals
; q3 {/ J4 O. n, W% W1 g8 M& d2 W[0 a( |2 s# k/ q/ h
  grid-x-inc               ;; the amount of patches in between two roads in the x direction( e' x2 \6 B- e, b* R( ~6 p8 ]
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
0 d) d$ c5 l2 e+ J" }  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
# U' {4 G6 Q! y                           ;; it is to accelerate or decelerate! \# k+ m. x! ^. B7 V2 D& |, B: K
  phase                    ;; keeps track of the phase7 B6 _* T, ^( x6 a4 v" ^( V! }
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
1 i2 F8 c% u# x/ w- y  current-light            ;; the currently selected light: h& B+ F* o" }/ E
( g2 h+ d4 u9 r# T
  ;; patch agentsets
8 y9 s- x- e- k, h0 X6 H3 C  intersections ;; agentset containing the patches that are intersections
# Y/ v2 U* u- C: {5 @& e# u  roads         ;; agentset containing the patches that are roads
; K" L: r- f1 s! i2 K4 `5 n1 J]  @2 d) o. V- f0 E3 R7 }! Y: ?8 |
' M# I' c  U$ M7 o. \
turtles-own  O+ W! M, e' ^8 Y" [
[
4 i) q! B0 _, {! a, n  speed     ;; the speed of the turtle
) G+ B' q# @8 Y* m/ x" V& N  up-car?   ;; true if the turtle moves downwards and false if it moves to the right; R' o5 H$ P3 q+ q$ {
  wait-time ;; the amount of time since the last time a turtle has moved+ u& ~  B. N7 m
]
2 K" m5 \/ Q/ }6 O) @1 _1 n6 L" a3 A
patches-own+ m& G- ]! Z3 @% T% G; @1 V
[
( n3 |6 Y: P( ]7 {  intersection?   ;; true if the patch is at the intersection of two roads
! s4 D3 X2 }: z  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
  V7 Y" Y  v! E6 ^3 {                  ;; false for a non-intersection patches.4 U8 C( a/ ?4 r' t  x
  my-row          ;; the row of the intersection counting from the upper left corner of the
" n1 ?' R9 s9 P                  ;; world.  -1 for non-intersection patches.+ M2 x  H4 R+ b
  my-column       ;; the column of the intersection counting from the upper left corner of the
) @5 V0 ~, D8 M" y/ b  Y                  ;; world.  -1 for non-intersection patches.5 E0 B6 @6 x; Z5 r& h7 V. ~# D
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
! P' E! X/ e+ r  auto?           ;; whether or not this intersection will switch automatically.  L" N7 T4 Y# Y2 q4 J/ `
                  ;; false for non-intersection patches.1 C7 w, o: d& J+ f* o7 U8 n
]' l6 O% w" r7 H

; |8 x: h, m) }8 ]  u  q) q5 M9 ~4 _( L0 g4 a, W0 L
;;;;;;;;;;;;;;;;;;;;;;
/ p" o+ @# |+ P$ @;; Setup Procedures ;;) w5 T5 ], o+ y8 j+ @
;;;;;;;;;;;;;;;;;;;;;;8 L* s7 s) M0 f& p9 f1 ]% b

" o9 N% M( S$ I( a$ X;; Initialize the display by giving the global and patch variables initial values.
) V, {1 i" q, `9 p. n;; Create num-cars of turtles if there are enough road patches for one turtle to/ s  q, c: i5 ?
;; be created per road patch. Set up the plots.- [3 f" I, }: d2 ^7 }" |. ?1 {
to setup' w+ I) I& g6 {$ ]" z& f
  ca
: L' D6 ^4 C5 ^& Q: b# j/ @9 @  setup-globals& m5 s; m% v3 W# o9 @

8 {; L: L. {, G7 [% l3 I  ;; First we ask the patches to draw themselves and set up a few variables
2 b$ G) t7 Q2 K% ~5 O$ u. u$ |' G  setup-patches' [/ ?$ x( b8 }7 }
  make-current one-of intersections
  A* F1 n, O, g4 B+ c3 j6 H7 p  label-current
: v- v/ d# ~& ]  _% P; N$ P0 E  C* C
  set-default-shape turtles "car") }5 Y; H" D  E; v1 Y, s- o

# @3 w4 z" Q7 E  if (num-cars > count roads)4 M6 O" |% f9 G
  [
+ J/ ^8 Y9 u$ T* A  B5 ?    user-message (word "There are too many cars for the amount of "
6 s- R; i, ^' W                       "road.  Either increase the amount of roads "
$ j! r: I8 ~9 U5 Y; Y* f) ~                       "by increasing the GRID-SIZE-X or "( L  D* s1 x: S" S
                       "GRID-SIZE-Y sliders, or decrease the "/ J! D# d/ ?  L4 r
                       "number of cars by lowering the NUMBER slider.\n", R7 {1 l( Y6 S* ]7 f$ U
                       "The setup has stopped.")$ Y3 q9 ?; f* Y# [  j
    stop
& F# |* C5 \3 g6 o  ]
7 t6 p' \) Y6 j* d  A2 s5 P- j' r0 ^& v8 }% ~. T8 u" H. B' o7 v
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color( q, D5 k. M7 z8 S3 h
  crt num-cars1 l# t1 Y% L( p
  [/ t1 s  h# ~* C1 [
    setup-cars9 m( T- I6 f5 e8 k  ~$ a
    set-car-color
+ Z) n5 {- i/ k( n    record-data: t0 b! X1 l: K
  ]
/ L" c3 C; h9 }% ~7 `5 C. B8 I6 l0 U2 @6 x
  ;; give the turtles an initial speed
0 ^4 T4 e  j0 k! R; ?  ask turtles [ set-car-speed ]6 H* d" `: Q) K6 t& H  b- k

+ g/ m1 R3 y/ O4 t  reset-ticks
& f& A9 G0 J* D# G; ~5 J4 ^0 s! Iend
: W) L! q3 E$ R  p" n. n' v9 h/ e7 e% }
;; Initialize the global variables to appropriate values0 S+ k* _- [9 @* m3 K. t( Q5 G
to setup-globals
8 }% b- _: `  W3 V  set current-light nobody ;; just for now, since there are no lights yet
( T: F2 W% |9 [/ ^& _  set phase 0
: L5 P) E, J9 ~3 D- C* i  set num-cars-stopped 0. r/ k4 P# i& a" U7 w6 \
  set grid-x-inc world-width / grid-size-x
8 r! [8 ]' ~8 r+ v7 H8 L& p/ Z  set grid-y-inc world-height / grid-size-y
9 Z7 P& e% [- Q/ N. m/ l8 K
# i" H5 Q+ `" E4 E- S: ?' X  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 m, R% _  V; J& M
  set acceleration 0.099
* k5 G  o( p* ^' ~end
# u7 {$ m& ]0 p7 ~6 ^, E6 }4 ]3 t3 E- x$ t4 B$ k$ f& ~
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
: C  k6 ]7 s: N& R5 d$ {& _;; and initialize the traffic lights to one setting) ?9 ?# Q2 L4 m+ r% C3 x3 ]
to setup-patches
2 h( e& ]/ W5 L6 _  ;; initialize the patch-owned variables and color the patches to a base-color
: f/ h' F# F# _6 a! K& B  ask patches* M4 b0 T  C: s4 k
  [8 m+ P& r% j3 E1 w, q. A! y
    set intersection? false
' {- p: B; z6 m' S    set auto? false8 H) j; G% f. P* b3 V
    set green-light-up? true
: @; Q3 f, A' `, `1 v0 x% l! \2 g    set my-row -1
+ s* U  R7 g8 x* |' k    set my-column -1
- ~" }6 g( X4 ]2 C. \    set my-phase -19 }5 H3 x' n# T. w1 _
    set pcolor brown + 3- P, W- H- X$ H/ C! v
  ]
+ ^, n( N8 n; Z0 I% u
2 s2 N" e& g& p  ;; initialize the global variables that hold patch agentsets
* I! M3 R. t+ z! Z3 J  set roads patches with, y" Y8 [8 D1 m
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% ?( l# N2 P) d7 u) I0 |
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 e3 z) E0 J; W1 L  }- |  set intersections roads with
( N1 C- L' M& g6 w8 u! I& }    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ W+ f0 e: I2 d% X; N4 ]    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 {6 ^" m4 a$ W
. H" ]& d5 y8 l$ Q  ask roads [ set pcolor white ]
! }$ ?7 p$ L. u- U9 P    setup-intersections, u  G5 m$ J. ^) \4 t
end
7 r6 X; ~) y7 {4 k3 ^* E; s  |其中定义道路的句子,如下所示,是什么意思啊?
) H; t- t% h1 G set roads patches with  Y4 E7 c/ I- D0 j( W
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
  J3 ?- e3 A% ^: k  V$ T    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 Z6 C8 u/ [5 H% ~5 ^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, 2026-4-9 10:14 , Processed in 0.016171 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