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: 7743|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。9 ~, B& C4 \; v0 B; d# h. B
netlogo自带的social science--traffic grid这一例子当中,
. ?' w# a6 e5 @6 x" {9 ~6 ^4 a2 iglobals# d  A( n; |% j* S7 w
[
; m0 O& v! t$ p4 |8 ]- K  grid-x-inc               ;; the amount of patches in between two roads in the x direction
; K. \$ K* c" N/ _. ?# n  grid-y-inc               ;; the amount of patches in between two roads in the y direction% r9 Z/ b/ T1 p% o# _) O. G
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
8 J: j3 I' l* s% p( h  q                           ;; it is to accelerate or decelerate
& \) D" q' V4 `& E1 y5 W  phase                    ;; keeps track of the phase
( Z7 \- {: j& W5 d% i! y) J6 `  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure: }& v  C/ n& R' a2 o9 k+ g' a' z
  current-light            ;; the currently selected light, L, _8 C% z9 J" ]/ @

7 c! C- \0 [; |  ;; patch agentsets9 T; ~( b: K5 t+ c0 _+ n, S. P
  intersections ;; agentset containing the patches that are intersections% R8 c. R$ e2 w5 W2 S: H. |- m
  roads         ;; agentset containing the patches that are roads
7 Z) Q) V6 s9 F; H* G6 }]
6 X/ H7 ]- C( r! Q( B4 d
$ J2 B" p/ W2 e3 E* bturtles-own
+ B8 C' a& ~/ [+ }8 n[3 y' p+ T# A$ v, e# b" T5 a9 C
  speed     ;; the speed of the turtle
$ r5 Y4 A  c& q9 R  up-car?   ;; true if the turtle moves downwards and false if it moves to the right3 q0 L7 }+ P3 e8 L6 r0 k  `1 j6 d
  wait-time ;; the amount of time since the last time a turtle has moved
( a$ r# L! m2 A; n, J/ x]
- h% E' p5 K: w7 m( Q+ b. @5 F; ]9 E' }6 f; F) H! t1 d
patches-own9 ?7 x2 I$ G9 j% f7 y
[# h  j/ g& y6 I8 u9 ~5 {
  intersection?   ;; true if the patch is at the intersection of two roads
" @: {/ E. ~& W9 Z- t8 t& I  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
9 D/ O9 O! [" n7 _6 k: Z6 a! Q                  ;; false for a non-intersection patches.
8 s3 S2 M' {3 U4 _7 J6 s  my-row          ;; the row of the intersection counting from the upper left corner of the4 Q0 K7 R/ O, i6 f9 S9 _
                  ;; world.  -1 for non-intersection patches.
! {  q% e. I1 X1 ^. A  @5 k3 o  my-column       ;; the column of the intersection counting from the upper left corner of the
$ T# E9 O! r' F! p                  ;; world.  -1 for non-intersection patches.1 c/ y- Z* U4 Q2 s. Y4 M4 ?
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
  s7 U6 B) N8 A/ o/ O. |& J  auto?           ;; whether or not this intersection will switch automatically." j! v) K, H0 x0 j
                  ;; false for non-intersection patches.
/ J0 A. M/ m% }6 L/ G! ^2 b]3 F, s! N6 K3 N' U5 ?# ~
4 s5 ^: L9 v6 P2 e

! u1 X' q9 A* o# M( {# D: ];;;;;;;;;;;;;;;;;;;;;;
6 L5 J0 e% y( v9 T- R/ j" T1 A;; Setup Procedures ;;( }- J: q/ j4 u- f8 e
;;;;;;;;;;;;;;;;;;;;;;
) y" T% n  Z9 A, [: n# v& N- E/ v" d* q: p8 P' @1 q# t
;; Initialize the display by giving the global and patch variables initial values.
. I0 u: N# y/ E! W2 R3 q1 K2 I;; Create num-cars of turtles if there are enough road patches for one turtle to4 u9 B8 r( g- \  H! ~  P
;; be created per road patch. Set up the plots./ f$ {/ {7 N) _
to setup  a1 |1 l/ `2 k/ I: G
  ca0 Y& c+ w0 A( k9 d3 H( S
  setup-globals
, U# S6 c" m* ]+ a7 h2 X, Z
# l6 E$ K  q. ^0 F5 {  ;; First we ask the patches to draw themselves and set up a few variables( D! K2 |9 d, m: a+ I. J
  setup-patches
) x7 ~- H% A* K4 [* D$ F  make-current one-of intersections% ]5 Q7 `3 U* ^7 m
  label-current
3 ~1 s2 c6 }- n+ X$ \2 ]+ X
2 v+ q' A; i5 z. r* t# d# Q6 r  set-default-shape turtles "car"
3 O# l$ M# U0 B5 j, d9 T+ A9 Q3 k- S, b: N
  if (num-cars > count roads)9 k  B7 ~9 U  c
  [6 y( q* V3 t* B$ Z: @7 T- n
    user-message (word "There are too many cars for the amount of "
  E* B9 X; ^# S6 i, w2 E                       "road.  Either increase the amount of roads "
% S& m* P3 B6 s/ t2 _: R                       "by increasing the GRID-SIZE-X or "& E1 n$ _5 v1 N& F5 p4 Y, B7 y
                       "GRID-SIZE-Y sliders, or decrease the "
# V) k2 y( a: L( S( F                       "number of cars by lowering the NUMBER slider.\n"
# T, x0 x& s: k3 f                       "The setup has stopped.")
$ w/ |1 e  f) `( P5 P+ a6 W    stop$ A5 J% ^- w9 d& {& }
  ]
( z% J( _# j& P: T" u
1 C) o0 J# O$ r5 k& _) J  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
' m- W: h; p8 n3 O1 R  crt num-cars0 V- j7 E% H0 @4 C
  [
6 S9 q3 B! t0 M- l- o( k7 ^" b) \    setup-cars
( l5 [) T+ F( ^1 G# M8 h    set-car-color
$ }6 r0 E. A  f% R2 F9 P    record-data! P1 z" ]3 }1 ^+ q9 C
  ]
# Y* z3 k( g. D  j" i) _- x! e- L
8 d' Z$ W1 r( J% `  ;; give the turtles an initial speed
1 S$ B" M4 r) B$ `( r  ask turtles [ set-car-speed ]
+ r+ n) g9 V. f. r/ f! l: x3 T  o: m7 |3 C( }
  reset-ticks5 s- U$ p$ X% H2 b
end
2 ~+ y2 F# I. P: _7 M) G- ?
7 Y3 e$ e; V+ e6 k1 y- K3 W;; Initialize the global variables to appropriate values. W6 e  N" S2 v' I4 N
to setup-globals7 Q( m! [0 l9 B8 {: W
  set current-light nobody ;; just for now, since there are no lights yet
+ W! N5 G% W8 d& D: |9 Q6 q: w  set phase 0! r& B0 x3 y, f7 b, C# p
  set num-cars-stopped 08 s3 U! C* i4 i+ P* K# Y3 g5 G
  set grid-x-inc world-width / grid-size-x8 K( G) L) y# I7 M
  set grid-y-inc world-height / grid-size-y
! @7 h" y9 }& k5 y0 M
, m5 \% b( w) c' e2 z; [  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- v) @3 P+ E) Y2 _2 E8 O7 k
  set acceleration 0.099% y+ t, c  C% J- s
end
9 |" l8 n/ h0 S- b  @. J% T# F* i) j8 V( X# J, l: z
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,  C! z8 J; y! _- ?; Y
;; and initialize the traffic lights to one setting
3 s, s: V1 |3 K% V8 h; e) _1 Kto setup-patches: o# \; X# w% p- |2 Z$ I
  ;; initialize the patch-owned variables and color the patches to a base-color
) V( F- R! X# z3 H  P  ask patches
4 F; ~# q& H. O; X& y. `/ G  [
1 c. i* ]5 E- p8 j7 R. X! S    set intersection? false- }. Q, X6 h, L6 P/ _2 I. G2 Z# b
    set auto? false
+ P7 I. h' J7 F: K    set green-light-up? true
7 M& g' U# q- X$ H/ j4 _4 @    set my-row -18 z/ u  S) {6 z$ `6 `0 d
    set my-column -1
: F0 t4 M, \% n; g8 Y    set my-phase -1( X2 j0 s7 t  J4 ?$ c5 T7 U  D$ X7 h
    set pcolor brown + 3
: Y# g# Z1 B! r& v: B: t  ]
' I8 R  F# O* A+ x/ x  @2 b" _8 }5 N, o+ @* t* b
  ;; initialize the global variables that hold patch agentsets- K6 T+ j7 p. a/ z' \  H
  set roads patches with7 U' |. T! \/ W
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& G1 A" A# T+ _2 J. d( B    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" y5 x- j% e. i* ?
  set intersections roads with$ `, p3 t  K6 c2 E& E' }
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
# z& f) _) ], @6 H1 h( Z4 x  a+ P    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: E/ R( J  l. \3 T; x
* [! ]& W% i# q& ]
  ask roads [ set pcolor white ]7 b, B8 V0 q* i
    setup-intersections, U! x1 b$ a4 r! E( H6 J
end
- `( z; J! M8 z! ^$ [其中定义道路的句子,如下所示,是什么意思啊?
$ Z" B; z7 Z/ Y# t2 Q' v set roads patches with
8 t7 g# f" f1 e& J. \1 e8 Q    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. O* v' `! f; G0 H) |5 t7 C/ C. i
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 l' O) I5 O0 ^: T6 O4 c
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, 2026-1-12 07:38 , Processed in 0.016612 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