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: 8318|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 I& E1 p4 A2 U
netlogo自带的social science--traffic grid这一例子当中,
/ M- j9 @, b! ^2 Wglobals
/ u" C/ A* f2 }" Z: C0 e" e[
- x5 q. P( e2 C, `  grid-x-inc               ;; the amount of patches in between two roads in the x direction7 `( {8 O" Q) m+ X* |! ~9 s
  grid-y-inc               ;; the amount of patches in between two roads in the y direction/ T9 [7 u* W  V( C
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if4 w5 E) \6 r) P
                           ;; it is to accelerate or decelerate
6 H  ~: w$ J- p- w: f, t8 M  phase                    ;; keeps track of the phase! q: s/ [# m& h
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure! F$ t+ F" H1 T1 l. G3 z
  current-light            ;; the currently selected light
) Y. J  E5 n+ \  V* G0 O, {2 |; Y
  ;; patch agentsets
/ {: r# ^/ O/ ]- i: s  intersections ;; agentset containing the patches that are intersections
; L7 |2 Z. T) ~  roads         ;; agentset containing the patches that are roads
& n! E  S1 n; x3 v9 Z4 r: H]$ _0 F  h" g. n, W8 ^
( S8 i, T9 E' K$ T. d' p; x: ?
turtles-own, h( h5 O& N$ V6 |9 l0 f) E1 ^" T
[
9 }* D0 n: z$ u5 u% G' t  speed     ;; the speed of the turtle
" k6 K- [% Q% }  T! m7 Y: Q  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
1 m5 T: x1 y9 h) z/ e3 T" t7 r5 U  wait-time ;; the amount of time since the last time a turtle has moved! X5 H5 W# r- \0 h7 T) u4 H
]% y7 r; u3 V. P4 ^7 ~3 w

. j3 U. g8 e4 vpatches-own% V) I/ r$ l2 ^
[$ ]3 d% w: I) [* \. B
  intersection?   ;; true if the patch is at the intersection of two roads! U5 o7 Y2 C. b' b( D
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.1 @- d6 _% K! P, l9 s+ b/ d- z
                  ;; false for a non-intersection patches.
' o4 j2 i, I1 v3 @  my-row          ;; the row of the intersection counting from the upper left corner of the
6 L+ ~' y6 `# V- f5 I                  ;; world.  -1 for non-intersection patches.
% w4 c! \4 S$ X' y1 \$ |; c8 u7 Z& w  my-column       ;; the column of the intersection counting from the upper left corner of the
  C9 Z, C) W4 e* o/ r                  ;; world.  -1 for non-intersection patches.
: A# T4 U& g) b7 O- j3 g: O) r5 G5 n  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches./ Q5 B4 _! i; j4 P5 x0 z6 k" ]# h
  auto?           ;; whether or not this intersection will switch automatically.
3 q1 u) _1 c* y" ?7 k7 e: @                  ;; false for non-intersection patches.3 c) P* K: L% @' L
]
1 U% {4 K0 o4 H& H- X) F$ }/ s# V7 o0 @  K1 G7 m, _6 x6 T

4 p5 m0 B9 q: s;;;;;;;;;;;;;;;;;;;;;;
  Q: l- c4 y/ R; g) m6 @;; Setup Procedures ;;
# \7 E# {2 }9 S" A4 T' C;;;;;;;;;;;;;;;;;;;;;;" C) d6 e2 Y2 a  E! `

* V2 Q4 I2 l# @4 H! d- j/ K4 J;; Initialize the display by giving the global and patch variables initial values., |; k6 y& s, [, ~- m- p* U
;; Create num-cars of turtles if there are enough road patches for one turtle to- J  `  e' h3 O/ k$ p6 o- @! [! o
;; be created per road patch. Set up the plots.
5 Y$ }8 _3 S9 u% _! o2 Z" zto setup, i; `2 s) ?+ k1 }/ m# S8 g
  ca
, x; f% P/ a* l' q& m, W  setup-globals( F4 H9 G9 s6 |! o" j& R8 \9 T

# x( t0 O* a7 k6 _- ?8 G) _  ;; First we ask the patches to draw themselves and set up a few variables
- t1 l9 b7 _5 B1 |6 G. z- \  setup-patches5 R& `6 o  q6 g" |. b/ K% N0 Y
  make-current one-of intersections* i- I. C7 \6 S" N, O) ?# H' C
  label-current
, ?. ^6 ^- j$ }' K
& s7 f7 U, |& J* o" D  set-default-shape turtles "car") F- x7 Q4 X. P- b7 S

3 P6 ]- e7 Z( t5 @  if (num-cars > count roads)3 E& w5 Q+ Y4 ?4 N) V/ @
  [+ c$ B* N2 n2 l# Z/ }- v
    user-message (word "There are too many cars for the amount of "
3 p. E/ C( E' ?5 M8 \                       "road.  Either increase the amount of roads "
! f7 n, T" N! D& \                       "by increasing the GRID-SIZE-X or "/ C) b& K4 B3 B7 @9 A
                       "GRID-SIZE-Y sliders, or decrease the "
% O. x3 r/ V. F                       "number of cars by lowering the NUMBER slider.\n"4 \1 |. }1 q5 R* [  n5 p4 ?
                       "The setup has stopped.")6 i' k! t4 R5 e; N! u* F
    stop
* _5 k" A5 y9 w/ C. b" i  ]" V7 j. r9 x) u

, b6 f, u$ B4 e4 P+ X  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
; E  c4 e( n: ?6 O  crt num-cars( w6 O0 o  s$ G. Q1 v
  [4 _: ?/ b0 s& o/ J
    setup-cars: B: \0 s: Q. t
    set-car-color
! v# ]! F$ s& c2 R: z/ v8 |    record-data
6 q9 g1 _( k( T  ]: i0 q' ]$ |" Z6 Y2 D

' s: W+ |( Y) t7 {& H, b  ;; give the turtles an initial speed9 K3 [9 `" S# i  J6 \$ C
  ask turtles [ set-car-speed ]' D$ h( E( Q* U4 x9 u

4 c" \3 s/ ]% H5 O+ q  J$ g  reset-ticks3 y) G. D% O7 ^+ o' w
end( D0 h; V( W4 ~

+ Q, |3 x8 ^- Q( }) T- o# P0 r+ k;; Initialize the global variables to appropriate values( h+ }9 L$ B4 P  t
to setup-globals  x, c/ s: Q8 ^# w* z
  set current-light nobody ;; just for now, since there are no lights yet6 b6 x& ]  L& P9 d- ?( V+ p; Z
  set phase 0
& k3 E+ B: p1 @4 ?  c: @  set num-cars-stopped 0/ K& @; B/ u1 w
  set grid-x-inc world-width / grid-size-x
+ c/ N2 ?# _) r# G9 `; O! c5 n$ G+ p# z  set grid-y-inc world-height / grid-size-y
/ M+ N0 x# o) _- _
; I4 `9 `$ v, ~. y  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 F! Q2 a) }1 J5 g+ q
  set acceleration 0.0994 f% D7 u7 O/ f5 T- G# f1 V
end
7 v0 o& c' F: `9 F% ?
; Z* i; ^7 W/ x6 ~/ l& r& K! a;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 \+ F( w4 s+ z: |1 Z;; and initialize the traffic lights to one setting
/ H* \2 o7 S9 [& ], ito setup-patches
4 ?* ]8 G3 B" j; _- b  ;; initialize the patch-owned variables and color the patches to a base-color, m0 Q2 C) r8 D% n6 B
  ask patches, ?! ^- u& r% q! Z; N6 Q# q2 R
  [
' R7 p; M7 S' r* r( k    set intersection? false1 s. w( z# I, t4 s
    set auto? false' A# k7 ~# g" I1 e4 l
    set green-light-up? true
! K9 H. m# V+ N8 A2 m- C    set my-row -1$ h4 D3 |& d# @. C  S
    set my-column -1/ p, \- V+ Y6 q3 W% k3 l6 b
    set my-phase -10 `% k2 N% |/ {" w" \, s
    set pcolor brown + 32 y* W8 k" h) z8 A
  ]
# p! Z( L6 c' H! k' K/ }. i6 m3 z0 B' R& S# ^/ N
  ;; initialize the global variables that hold patch agentsets
% S4 `! N7 u% @# Y2 t" [  set roads patches with1 h- H- S6 q* V/ J; I% M
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 @2 W6 I; H% S4 w: A2 X    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! b0 }; c1 p/ U1 O7 P
  set intersections roads with8 L& u0 d2 f3 p" |3 e$ ?2 N
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# T5 B3 U5 s) m  q8 {2 S
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' F7 {# ~' @% |  X: w' k  _% k. l- j3 f* c
  ask roads [ set pcolor white ]4 Q& p5 O! L# R; Y3 B
    setup-intersections
8 R: ?( z% B/ ?) q& M) O  _4 {end) S# |0 }& G# F9 P8 ^4 \
其中定义道路的句子,如下所示,是什么意思啊?
3 P6 s" }$ N, |/ ^/ i" e set roads patches with1 r) b# {$ E8 c& n2 m
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 e9 E1 E/ b0 r- u    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ [0 v+ p& Z/ D2 O* A5 X  [) a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, 2026-2-12 00:14 , Processed in 0.015033 second(s), 14 queries .

Powered by Discuz! X3.4 Licensed

© 2001-2017 Comsenz Inc.

快速回复 返回顶部 返回列表