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: 8223|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 I! }* _# d
netlogo自带的social science--traffic grid这一例子当中,
5 ~( o" R. v1 _9 qglobals
2 Y3 W6 s! r& O+ s& k5 H[4 ]5 F/ W" E- D% D% x/ A" `. C6 \
  grid-x-inc               ;; the amount of patches in between two roads in the x direction9 o& s# o- k4 j# o& i
  grid-y-inc               ;; the amount of patches in between two roads in the y direction) S6 ~4 Z: _! [1 a  e! `9 ?
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
. X3 t% Z. I) q  x                           ;; it is to accelerate or decelerate( A: E+ r8 z. b1 p1 r) k
  phase                    ;; keeps track of the phase7 L2 c- m3 I# j! r
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
4 T+ }% W6 y1 `9 I- T* t+ q  current-light            ;; the currently selected light
8 s& x6 h  V  D) Y7 O% m5 Z- V. b! `; r9 _' T. R9 C
  ;; patch agentsets
9 X' z8 ?8 I+ U# T3 v+ k2 @  intersections ;; agentset containing the patches that are intersections/ g. v# [) z2 e6 v! r
  roads         ;; agentset containing the patches that are roads
  G3 x( V6 v) Q+ n/ w* a  y+ Z]( h! w8 r9 u( z8 L
7 R' K7 S5 |, X) x* j' [
turtles-own
8 p9 e( H, i' U2 O0 K[
$ R. _8 N& D& R7 g  s- P  s3 Q  speed     ;; the speed of the turtle% A& D& b9 J6 r5 \% T
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
9 Z* I; [) v- m) C+ J  wait-time ;; the amount of time since the last time a turtle has moved7 U' n" d9 D. ?- M
]
+ ]. w9 B7 q  h0 z" n/ Z. c% C  I/ L7 e* _( V" x0 u0 W
patches-own
2 I7 `% |( O, I' t% Y  t6 j+ A0 `[7 i' K8 K! V0 g
  intersection?   ;; true if the patch is at the intersection of two roads
5 Y: h4 q' I- y! M, B  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.5 {. L7 x0 |  {
                  ;; false for a non-intersection patches.
3 A  p: M9 @  Z. B( o) y* g  my-row          ;; the row of the intersection counting from the upper left corner of the/ Q; h( Q: ^7 ]# K  e: y
                  ;; world.  -1 for non-intersection patches.& ~" g2 b) ]" H. Y4 [
  my-column       ;; the column of the intersection counting from the upper left corner of the7 i: @! ?5 E" I0 L6 D- p% J
                  ;; world.  -1 for non-intersection patches.
8 d# j: `5 ~/ u; r  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
4 P/ \3 R. \9 `1 q* b  auto?           ;; whether or not this intersection will switch automatically.$ G% [  {/ K4 q8 r/ F2 G
                  ;; false for non-intersection patches.2 `" k  Y6 X. f/ i7 u% d, V) Z
]" O( z% R# S9 E( c# t/ `% L

1 k+ {4 A$ Z. Z$ ]/ N
5 ^; A  _' x& n0 N0 ~$ D. R: o;;;;;;;;;;;;;;;;;;;;;;0 V: J* @; ^" o
;; Setup Procedures ;;
: w% ]* F2 _, F3 j$ s6 I/ j* k  v;;;;;;;;;;;;;;;;;;;;;;
: F* y, N8 X6 @) \( A6 [4 L  f1 p' K
;; Initialize the display by giving the global and patch variables initial values.
+ t' _* x' w2 |* w* w5 e4 \;; Create num-cars of turtles if there are enough road patches for one turtle to3 ~# e7 V6 C. N0 i' `8 q
;; be created per road patch. Set up the plots.
* Z' ~2 A) c. U  \to setup
8 n8 F+ k& n0 m' Z' i  ca  F; J3 E/ n: \0 u. H
  setup-globals% ]& E6 H: \* G1 K2 l  y0 O; e

: O( b' P" T- e- U" q' X  ;; First we ask the patches to draw themselves and set up a few variables+ d. x' x3 @* l7 W3 ?
  setup-patches. j: Y# k: U& C) }# U' t
  make-current one-of intersections4 O, K% u6 ]6 y9 g" p* h
  label-current
8 r+ y, a8 U( D; W
% U5 y$ p6 h  [0 ?# P  set-default-shape turtles "car"
' P  X' M8 [3 \: C7 r1 q
4 V0 u' u* W* V  if (num-cars > count roads)
) O- F) k8 v% ^/ d* A  [
1 x/ J. f' m1 r- I    user-message (word "There are too many cars for the amount of "
3 Z( p6 K8 _2 P                       "road.  Either increase the amount of roads "
1 J9 B& U3 O) b* C( \5 l6 J- O6 |                       "by increasing the GRID-SIZE-X or "! y/ s7 t! T/ t% i5 I9 x
                       "GRID-SIZE-Y sliders, or decrease the ". l- B$ _; Z, _0 J6 I/ m
                       "number of cars by lowering the NUMBER slider.\n"& n. }9 z, B9 W) O( f+ K
                       "The setup has stopped.")
$ A6 ]* W7 y$ b+ y    stop
& o* K. u; c! }+ K! i3 A' Z  S1 @0 k  ]
' q! s; d% @1 s; I; V! H9 m$ ]5 W2 h/ t& G) J. l& q6 i0 l
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ U! }8 ^$ K! c; Q  L
  crt num-cars# I( ^* G$ q( _4 m6 F
  [
! C2 }8 i) f6 w" B% |: T) h. G    setup-cars
. y: p- n# C; t  e6 O  S3 r/ g    set-car-color
$ f5 C4 A  U. d: Z+ ]- h    record-data
1 I1 A( l7 p- G5 J  ]# ?& x% S" f/ j( G( z$ [6 F

! R- O' c3 I2 V  ;; give the turtles an initial speed
; s7 z1 j. x( M2 a9 ^8 D% p9 C) Z  ask turtles [ set-car-speed ]& W5 Q$ P. I9 I. P2 D

0 u1 p% L! @8 x' P' w2 G4 ?  reset-ticks
, C7 A# g8 \- nend3 X% Y; D4 P4 U9 o+ l% Q5 g+ e

3 A+ l4 Y) A6 L: b;; Initialize the global variables to appropriate values; Q- j* P" t9 f+ r: u
to setup-globals5 u) [% l6 q: r/ F
  set current-light nobody ;; just for now, since there are no lights yet
2 o" b, K& s' U7 K  set phase 0
0 Z4 y0 z1 D" G( G. [  set num-cars-stopped 0. {3 ~9 @, w, z3 `; E& i
  set grid-x-inc world-width / grid-size-x7 x; R, X, i, {# ^3 }
  set grid-y-inc world-height / grid-size-y6 d" I1 K. Y4 g7 y) a& H1 I" u
6 q7 A; j# ]" @) n& j
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) p3 H& {1 ?3 x% s  set acceleration 0.099
2 u, K) U7 g2 yend, Y3 S& w" i0 o
$ T* g8 i; o- V7 C& |, v5 [' f
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 S# s6 @& S  T1 l;; and initialize the traffic lights to one setting
( L2 n- h: B8 Q$ D$ y% l! {to setup-patches
1 U* X! \5 q) Z) p  ;; initialize the patch-owned variables and color the patches to a base-color" h$ O( p* A2 n$ R
  ask patches
. \& s: T% ^8 r6 z  [
3 K4 y6 d2 C/ x- _" c; A$ W) t0 B    set intersection? false
+ Z$ |: G* B" n2 ]  c, P    set auto? false
9 Z2 O3 N: i, ?: ?) a    set green-light-up? true: [; }( w( z" v. p* J. Y
    set my-row -1: t; e& }* L9 p4 M2 y! T
    set my-column -1
$ h/ ~0 B7 k2 Q% ]6 i. R- _" K    set my-phase -1. L: j8 ~4 p' Q) d
    set pcolor brown + 31 m- e$ n  L- p# l5 ^, A# ^1 s
  ]
+ f( ~7 A) s9 ^$ a5 ?3 K4 w
; {7 r% K' c0 l- r9 N- |% [  ;; initialize the global variables that hold patch agentsets7 N. F5 A: Y1 e0 m! O3 N
  set roads patches with
2 w$ [; H$ T0 @# S! a7 W3 v    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" I/ D% [' [( d& Q% W
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ \6 }& W0 f9 G
  set intersections roads with/ {. F9 V9 J- R% t
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 H- y5 r/ |% u4 e5 Q* q. i    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: j$ I4 j4 [* r! k( N* v
' h. o3 k( Q5 ^9 @  ask roads [ set pcolor white ]( v' c" E- p9 R: ^, ~
    setup-intersections
# P- g) Y- @1 ~5 \end
" Z7 k" d5 H( e7 o0 x其中定义道路的句子,如下所示,是什么意思啊?$ g% X( Z; ^* V) W. |, X
set roads patches with% `5 h2 V$ Q( ?8 f% I' d" k+ h/ m
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! R! V9 L( Y+ `! G) \' [: W
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* U. a" I7 {- C7 `- ~* Z: w4 g/ ?! _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, 2026-2-7 10:05 , Processed in 0.019043 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