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: 8599|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。8 {( C* }0 [# r
netlogo自带的social science--traffic grid这一例子当中,
8 B; r) A; w, g+ d, q: wglobals
. @1 u0 [% J  C3 D1 C( @[  D. J3 I0 Q5 V# \' z
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
3 M( v3 Z9 n' d, d* x6 t  grid-y-inc               ;; the amount of patches in between two roads in the y direction
9 R9 q0 a2 z& E8 k( S$ t  acceleration             ;; the constant that controls how much a car speeds up or slows down by if" @  B8 U. b: j# T8 `9 Q- X
                           ;; it is to accelerate or decelerate
: x! K% D- ^6 ]; R( r% x6 {1 ~2 [  phase                    ;; keeps track of the phase
. ~) e( n  k' b' h: W/ _5 F* h8 k  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
3 M/ }  _' k& W( y  W% |$ `  current-light            ;; the currently selected light1 Z+ b9 |2 g$ m9 @0 B5 b+ Q2 `
* i6 N6 ?( r' \' d: v1 k
  ;; patch agentsets
# e- Y. f) j& S4 T& X  intersections ;; agentset containing the patches that are intersections+ \" q$ O1 x  e1 `. N, E& W
  roads         ;; agentset containing the patches that are roads2 U' z! e) B/ @
]
# Z+ c; y$ w* c/ X1 o( N3 }# Z& s! R+ o$ P$ p5 o; h
turtles-own
! D. B# W# ]; Z# o- B7 c[
/ t% I/ i7 |4 f8 L2 F  speed     ;; the speed of the turtle
( _' ]' [% v# X/ H. }  up-car?   ;; true if the turtle moves downwards and false if it moves to the right6 O) ~3 t4 v9 T. M1 `
  wait-time ;; the amount of time since the last time a turtle has moved
; n5 l# a' }; F$ c]5 P9 w# V8 I5 @
% Z7 O6 g& u0 d; D+ N3 e5 _3 h4 l
patches-own
) e' R% H, N, \* P[
! n* R& B4 s6 E) p$ V1 y, n  v$ S  intersection?   ;; true if the patch is at the intersection of two roads
  F, _2 C$ a( A- x  i9 N  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
8 p0 D6 b, x% X                  ;; false for a non-intersection patches.
: D/ _$ U7 v, u/ P+ u  my-row          ;; the row of the intersection counting from the upper left corner of the' J) R) Y5 z+ p  _+ p7 b
                  ;; world.  -1 for non-intersection patches.
. b# x# d% U9 v0 T1 S4 G! G  my-column       ;; the column of the intersection counting from the upper left corner of the
% j9 b. I9 z# I( N4 Y( h                  ;; world.  -1 for non-intersection patches.( A1 \7 w: H6 d: N2 t2 Y
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
( g7 V- i, o6 ]  auto?           ;; whether or not this intersection will switch automatically.
) j+ X3 d- H9 I' ]! X" z% N                  ;; false for non-intersection patches.
. K- E! z% Q9 O! t$ n" K]
) @7 Q( J* N- b; y+ X9 m
0 C1 E( ^3 ?3 q# Q# Z+ a9 y
6 u) u* i4 C9 p* a# D+ q" h;;;;;;;;;;;;;;;;;;;;;;
0 a. ~, z+ B7 ~- V' R;; Setup Procedures ;;
+ c! z* u, p$ n;;;;;;;;;;;;;;;;;;;;;;
. N4 o$ _- J0 d# K$ b, `/ D# ?+ h" Q6 y9 G! o" A: N4 o% b
;; Initialize the display by giving the global and patch variables initial values.
/ ]7 `' n. V( A7 m3 E3 n/ f;; Create num-cars of turtles if there are enough road patches for one turtle to
: q9 C. I8 S4 M" F# Q7 F  f" B9 a; k;; be created per road patch. Set up the plots.; u4 }8 w. s2 L6 F9 B1 @
to setup
6 t* C$ ~1 }% Y2 {" I  ca9 U: Z6 j+ O4 H' u* O. T3 j; Z5 O. t
  setup-globals
, l7 X6 k2 `+ Y% w1 M
" w- K0 {$ w& F6 b2 ~  ;; First we ask the patches to draw themselves and set up a few variables% \% \; Z% g0 i# i* y7 q  U0 y, Z
  setup-patches
0 l4 U1 j# F; D+ k" j) n  make-current one-of intersections3 k! G% ], m2 p+ @
  label-current' K. |& A, g2 s, H: A6 x  i

$ {9 n. w8 w0 `' W( [& J- ^- f2 |& t3 _  set-default-shape turtles "car", Z9 D: n+ d4 Z6 F2 H; B

4 L' u# k# x2 [" ]: X( i+ X  if (num-cars > count roads)
7 ^- L: ~' L9 \8 A. G6 W  [1 M5 ?5 S' O- w
    user-message (word "There are too many cars for the amount of "
$ {7 T+ {! r9 X+ T$ C                       "road.  Either increase the amount of roads "
, X/ Y' U) ?( e                       "by increasing the GRID-SIZE-X or "
& @% E. i6 d8 `9 M+ b3 k5 M; W                       "GRID-SIZE-Y sliders, or decrease the "
0 z8 n3 N/ G6 y1 Y7 i; R                       "number of cars by lowering the NUMBER slider.\n"
4 z4 h) Q' U7 @! G- k! }% j                       "The setup has stopped.")4 y  [4 B$ X3 N7 T( t, g  L! F
    stop
" \* Y( U8 p8 ^9 Z; i) X  ]
5 Z( _& j0 A% b( w- c* n
4 e7 v+ s7 h& N1 W/ Z! [! |2 @+ W- F  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" _/ l8 X# k; f" T1 q$ _0 z+ N: Z  crt num-cars
5 K3 y9 T" x% ?  E$ R  [" F- \1 f: o, O7 B
    setup-cars3 B" W4 \, S, C# ]" m
    set-car-color6 K0 f) f, P. K) u# C8 _
    record-data
% t& {" l& H* f  ]' T# c7 ]* T0 X

  [. l8 a" H% |* T4 E$ v  ;; give the turtles an initial speed
6 g; C# S& ?! D" F  ask turtles [ set-car-speed ]
8 ]! t+ t3 @! y9 M6 _  R" E' T- h/ o! O) r0 Z8 f0 J+ A% f
  reset-ticks6 M9 [! E! v* L6 L. y& z
end
: @, a2 w9 |  T6 G, J) E# \$ M; d# ]& `  p" `# u! [
;; Initialize the global variables to appropriate values7 L) a5 m- d: L7 g" S5 x) G: X
to setup-globals
$ _* k  B. D1 l# d  set current-light nobody ;; just for now, since there are no lights yet
; a( G0 Z- b" @) A2 ^7 t' G7 O  set phase 0  o8 G/ Q( X, q" c8 @' H- Y% U
  set num-cars-stopped 06 R; c- k7 N1 k2 m- L# L! o+ j/ I
  set grid-x-inc world-width / grid-size-x
; G' a$ w" B" c  set grid-y-inc world-height / grid-size-y
% C+ z" _5 r% p" F. y" ^6 {2 e4 A" Z
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ o- Q0 K. s: b& e% q3 B
  set acceleration 0.0995 ~1 f0 F2 f% D- J
end
* Q& k' p2 v9 ~/ f8 k: U
1 T6 y% A3 H* p8 W;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! J. c, j3 b" W5 N7 F, c7 j
;; and initialize the traffic lights to one setting3 M2 {% @7 {# j
to setup-patches
4 h( h' k! Y1 \# a  ;; initialize the patch-owned variables and color the patches to a base-color
" I6 i9 d( [" Y9 U  ask patches) g  v* r+ w$ f2 R, j7 }
  [- D8 n0 e5 x3 V+ M4 J
    set intersection? false) e! Q# a0 G/ i, p5 b. f- o0 V
    set auto? false& b" u# I; [" q+ w$ _; ]
    set green-light-up? true
2 S+ \' {% R+ U: I! e    set my-row -1
% _2 E& V- T8 p; T: D* r+ y, _    set my-column -1
9 A0 |4 U# V/ d    set my-phase -1& |) D3 h0 \/ l! ]
    set pcolor brown + 3
% {$ r: T3 A  ~/ \8 F9 \  ]8 c# p! A  o& E8 y, L

6 P: y# w) `9 q  ;; initialize the global variables that hold patch agentsets
4 w0 {/ [6 ~. Q5 h" c5 X  set roads patches with% e$ v3 S4 o3 y& ]+ M" Y
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 R3 z- v' `0 q# c* g( i    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# G! u0 K% F$ I/ {! r5 ]
  set intersections roads with
0 u0 A' P7 U- L# g+ |% W6 J    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' S, k5 y, h( f% U5 Q  g" |. E    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! r8 T% h7 D: j* @5 ]

6 s+ L! e- f( ^  ask roads [ set pcolor white ]
2 `& j$ Z4 s3 R  ]( s    setup-intersections; K: Q/ D6 _* U8 z
end
2 u% G( p( y8 Y/ z$ C. q其中定义道路的句子,如下所示,是什么意思啊?8 P' A( N- t  k5 i3 C8 l
set roads patches with
2 H$ b2 Y1 @8 E; q$ i    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 X5 \, ]: C0 c! }( u3 T    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 A6 v% G* S/ Y8 T5 ?3 b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, 2026-2-27 05:11 , Processed in 0.021609 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