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: 10948|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。# a5 n8 m# o, Y( y% O3 v* m
netlogo自带的social science--traffic grid这一例子当中,
( ]% E: C( W5 o6 o. y4 m7 y; lglobals, N- Q) R, u9 v, X6 @' b; p. m
[
; w6 I( \$ \4 v; A+ B- d  grid-x-inc               ;; the amount of patches in between two roads in the x direction
/ B& i) ]- x1 \% C+ P& ~, Z, h  grid-y-inc               ;; the amount of patches in between two roads in the y direction
( }: i; H: ?! O1 l  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
  Y( y- Q( m! E                           ;; it is to accelerate or decelerate( s2 V/ c2 N' `' I& x# i8 \
  phase                    ;; keeps track of the phase" `4 u' Q$ }8 v6 ?9 g5 p
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure( r3 ~7 t/ ]5 X  ~# L+ g- Q! f% N- _
  current-light            ;; the currently selected light
- ?+ ?/ T- N2 y% o) R+ _) @6 }1 j; M% ?2 m% V
  ;; patch agentsets! r( @- R" o/ r1 j% R) M
  intersections ;; agentset containing the patches that are intersections$ J3 K- ?6 U5 R2 X& b" Y& h
  roads         ;; agentset containing the patches that are roads
: {4 j7 J9 l- U2 l  k, k% ~]
" H) k0 ?' E8 @2 s. @* L9 u
+ d5 x; O/ K5 F' f% Y4 M. Rturtles-own
( Y9 J/ w) i  z; r& o[3 i# o7 t. p9 d
  speed     ;; the speed of the turtle
: P4 d! K* M, s, ]  up-car?   ;; true if the turtle moves downwards and false if it moves to the right# a; F' i( S1 @' A/ Z6 X% I: E
  wait-time ;; the amount of time since the last time a turtle has moved6 S8 h$ l" m2 J; p3 `0 B" x
]
( t! r' P  W! C# \1 n7 ~, D% R9 Y8 Z6 \9 `4 R! k+ N2 W4 ]. g
patches-own
# _) O  P8 _  G. R* ^; o, i/ m[
- s( b5 ?8 s5 @. d, H7 e  C4 @  intersection?   ;; true if the patch is at the intersection of two roads9 U8 ~0 r- q9 H2 H
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false." j7 U  M9 b9 T
                  ;; false for a non-intersection patches.* H( R9 i$ M+ i3 W" N' w1 j9 _* l
  my-row          ;; the row of the intersection counting from the upper left corner of the
- T, f( N6 U$ d0 F  L& s                  ;; world.  -1 for non-intersection patches.
, F4 V' R, A+ f- z  my-column       ;; the column of the intersection counting from the upper left corner of the
9 I) t+ p' X$ Y. _# O& s                  ;; world.  -1 for non-intersection patches.
$ Y" o- @) @1 _& `" V% Z  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.; N6 Y4 e  l% B7 _
  auto?           ;; whether or not this intersection will switch automatically.
! B8 S- ^! T) I, P                  ;; false for non-intersection patches.% G" }* |8 ^! D7 r2 ?
]2 Q9 g5 u- ~" q6 _3 F# |

/ h4 G( k. D$ a7 G& Q- S: ^1 O" i
* C  s9 t- W, r( [- Q;;;;;;;;;;;;;;;;;;;;;;
! [; S% u& ?- Q/ X;; Setup Procedures ;;7 N. d, i7 [- x: O* z
;;;;;;;;;;;;;;;;;;;;;;  Z6 A: h, o, G% ~

3 {$ V6 h0 D; _;; Initialize the display by giving the global and patch variables initial values.
0 o% n2 d$ u0 N5 B: E  j6 W;; Create num-cars of turtles if there are enough road patches for one turtle to5 h- i) `! A; e# j7 |) k
;; be created per road patch. Set up the plots.
6 M* \. Q' D9 q$ O  c* ito setup; d% j0 P$ N9 t
  ca
4 S: e' w( ?$ t. I: v  setup-globals9 X  o4 |7 A5 {( P' i- Z" D
; G% C# W* K3 G' N! s8 Z$ `6 m
  ;; First we ask the patches to draw themselves and set up a few variables* |; C7 a5 c# d/ l7 U0 V3 m! a9 \% a% U
  setup-patches1 H+ L/ O4 G6 B
  make-current one-of intersections
6 I7 U) O/ s3 b0 H( d  label-current
/ C, P! K3 u/ c7 T0 }+ o9 r, Q
8 G, o1 X8 Z* `/ L8 y* D2 M  set-default-shape turtles "car"" w% d8 v$ \4 h' @% [. T

8 Z1 Q  G2 ?( Q8 R* r7 u3 P6 q- X/ f  if (num-cars > count roads)' }+ ?# W8 i4 ^0 v8 Z6 |
  [0 x* C" b+ h, d3 f: N- N8 W" t! K+ a
    user-message (word "There are too many cars for the amount of "
, a- h! y% v0 P* C7 N0 D! u# \* U                       "road.  Either increase the amount of roads "
0 w! f7 X; e7 B% @; [8 N: ^                       "by increasing the GRID-SIZE-X or "* ^$ {) n3 y( k7 ^$ q9 Y
                       "GRID-SIZE-Y sliders, or decrease the "$ D% b4 E2 o1 q& `2 x0 b& p
                       "number of cars by lowering the NUMBER slider.\n"
9 L8 V: J- M3 Y& g9 g$ K                       "The setup has stopped.")8 `- Y, \7 _7 U1 X+ G3 F
    stop
. I. H: G9 t' A/ r# A  ]$ J9 m( v6 U) R1 v# _
- K1 f) g/ Q; }1 N4 t
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# S# ]% j  W' U1 N
  crt num-cars
% Z. T0 o( L0 \" Q* k' A: T  [
% ^& Z+ p  k9 D- c; E; z2 {- m    setup-cars
, O: o' J# C+ S* s% A    set-car-color' E) T  \2 @# J8 D; E- H+ l+ U
    record-data2 S7 a* n. A# ?: a! q' V; ~
  ]& G' V* H  t2 w5 [; V" E% n4 m
6 {3 I- T2 `5 i$ q  Q0 t
  ;; give the turtles an initial speed
! ~3 n/ r1 }- V% r/ T  ask turtles [ set-car-speed ]
1 k) i& z. g; G0 m6 E  ]: P$ _% w; W. ~5 H. Q' o8 M
  reset-ticks
0 E& L  E! h3 Gend, b1 ?9 H9 K1 t! B

3 P- b9 |6 |; K3 e) ^5 W;; Initialize the global variables to appropriate values
1 }, E4 x( E& Z7 e0 ato setup-globals( j1 c% p; g2 h2 r9 V
  set current-light nobody ;; just for now, since there are no lights yet0 s: _  u/ N- D6 `1 }0 O
  set phase 0
6 r+ R% g# H  Y+ O  u- Z1 H  set num-cars-stopped 0
5 N' J2 z6 t: H! j  set grid-x-inc world-width / grid-size-x
, h/ K' W& ?0 D  set grid-y-inc world-height / grid-size-y
4 C! ^2 R2 G+ m5 L) S* d& \; n7 ^5 j6 [( [; g0 ~6 |8 M
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 p* M. r3 y! e5 K+ [. [. L  set acceleration 0.099
# g& U7 X2 Q: H* C: R* {- Z% ^end. D3 B1 ]4 Y8 @$ Z0 b6 {0 v, C. }& Z

5 b: k8 |; |6 @3 j* Y0 X6 B;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" i( L# B$ v! e+ ]% k* _9 E3 E;; and initialize the traffic lights to one setting
( z, ?6 X$ [, x7 Zto setup-patches
4 B# l2 D/ o. K7 m6 Z$ [6 y  ;; initialize the patch-owned variables and color the patches to a base-color9 O3 c" B9 B9 G# x, e7 L, G: V8 k5 N- \
  ask patches
: s- q( S# J; ]( w: g% ~  [/ O6 d6 {6 a% `; C: h+ G1 j
    set intersection? false
; |  k* ?0 a" [, w! B. f    set auto? false, f2 c) |* }% ^2 t) w
    set green-light-up? true; J- O) D1 x! r  ^7 p
    set my-row -1( s( ^6 V# N& m4 }* @3 j
    set my-column -1$ K( J8 L" ]' S; Q" b- l/ T% [
    set my-phase -1: _/ G7 _/ r& s1 U$ j+ C$ k2 b5 p- j
    set pcolor brown + 3! [; H; x* ~5 c9 h& C; ~1 b
  ]5 n' u: |4 _3 I4 Q" c  k& i/ G  ?

% }0 _0 L4 }/ B0 a' I5 F  |. z  ;; initialize the global variables that hold patch agentsets
, L% a; @9 J, r8 g" R  set roads patches with" D' h5 k: P3 V: o: l
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( S1 F2 v) ?) _; m" ?& A8 `9 @    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% `. R7 r& t& M  set intersections roads with
4 j- n: e; A8 z0 u$ p    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and$ d: ?" x$ o9 c5 f7 B. K
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" \; b1 [3 C( h" t: a

) e: v9 @4 N6 A5 z  I  ask roads [ set pcolor white ]- b7 h  M9 g. Z" n8 q
    setup-intersections) Y( b& C$ M& N! Q3 z9 W
end( X8 r# P4 o3 L4 T% I# s6 W$ j5 j
其中定义道路的句子,如下所示,是什么意思啊?$ y4 e) k! a& j! {+ E' Q) N  x6 B: M) t: D
set roads patches with9 q- y- D3 b# Q+ r; v+ s! z% i  L7 N9 a
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ J6 {0 J/ R& t* ]( s0 ]
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)], v- z4 M* O# M
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, 2026-7-6 14:25 , Processed in 0.015153 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