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: 8234|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。
( I6 \3 r0 T; w  Dnetlogo自带的social science--traffic grid这一例子当中,
+ q- W0 f7 j5 g% l/ n+ K9 \globals% o" h; Y! `% e6 D% v! ]
[
3 L6 t& l! l$ f( p, c) p# ~( @  grid-x-inc               ;; the amount of patches in between two roads in the x direction1 }( Q2 ?+ m$ Z
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
4 n& ]# a6 Z+ }/ Y8 A2 ]  acceleration             ;; the constant that controls how much a car speeds up or slows down by if( r: a% }- y/ A4 ~- y
                           ;; it is to accelerate or decelerate
! c, r: g% ^0 n8 V# I* R! E4 k  phase                    ;; keeps track of the phase
3 t$ x+ Q* s$ V# f# N3 _5 ~" _  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure% |& W. a5 n" @
  current-light            ;; the currently selected light
0 K* w; N  G# I9 o5 K2 M  S8 B4 ~+ t2 s4 N9 D3 b4 V
  ;; patch agentsets
% j, C5 `9 S/ p, l. o) l3 e: c, d& T  d  intersections ;; agentset containing the patches that are intersections6 g& g6 B. y2 _4 O- B" z
  roads         ;; agentset containing the patches that are roads/ ?) I5 g' H% O" _3 j$ L
]
* _3 \; J" H$ ]( n: X1 m7 r# J4 X' l2 g
turtles-own4 o, j. q# B* n; K& @
[
$ P+ s* }( a: E# r; k. {: _  speed     ;; the speed of the turtle6 @6 x. Q8 D4 |0 h- b
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right6 o6 Z8 F# }+ `
  wait-time ;; the amount of time since the last time a turtle has moved
! Q- @( h$ g; m- o; `* o" B% O]' ~9 L  ]8 `- h  b& c2 Z, O: L9 C
5 r; G. [" O2 a5 U5 G6 ^
patches-own6 l# J: ?8 ?% `2 j# N- \- K5 W
[
1 u* H  R0 ]# |6 ]  intersection?   ;; true if the patch is at the intersection of two roads% z, \) ?1 Z4 I% E5 R
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false./ ^( }2 J2 B& |9 B) w
                  ;; false for a non-intersection patches.' ~) t! V) r' l* y6 p/ _, j0 W
  my-row          ;; the row of the intersection counting from the upper left corner of the
% y; U# ~6 J# w. `. N$ D& @8 B8 Z% [                  ;; world.  -1 for non-intersection patches./ f! O! x& T, O% Z# U9 J" @- X
  my-column       ;; the column of the intersection counting from the upper left corner of the
( ^* B6 I, @4 T1 q/ ^                  ;; world.  -1 for non-intersection patches.
6 E% v/ v; ]0 k1 G  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches., [6 Y, ?) }* T2 J1 ^+ K. f  N
  auto?           ;; whether or not this intersection will switch automatically.% N1 i) Z2 Y4 h( g- z" T
                  ;; false for non-intersection patches.: V" ]7 u0 e% ?* K* ?) X
]( v  q. H. T$ @% |9 o4 e

/ d  x6 N! A1 r* Y) m) O, a0 ^8 w- q8 ?/ ]1 u/ h' b( j
;;;;;;;;;;;;;;;;;;;;;;5 W2 f: Q8 R; _/ {; |
;; Setup Procedures ;;5 e% i* T& Y1 O# ~, F. Y" A
;;;;;;;;;;;;;;;;;;;;;;5 ^& J4 c# a( d* n3 r2 L

. }* P/ Z& H* G0 W;; Initialize the display by giving the global and patch variables initial values.2 K5 e* C: ~( x: V/ j! g, m* i
;; Create num-cars of turtles if there are enough road patches for one turtle to6 X2 [; a8 w) _2 [. o2 U  h
;; be created per road patch. Set up the plots.
0 X2 J+ h; G. _. S, Tto setup
6 h/ Z+ Z+ O; o6 M. p4 }# V3 E. Y0 y  ca; W# ]- s# Y  i2 v8 E; H. y% P
  setup-globals
/ @' A9 k1 i' m
# I1 \0 P# v% |- K  ;; First we ask the patches to draw themselves and set up a few variables
! p' p, E% u4 J1 t8 v9 V! K9 _5 l  setup-patches
4 `$ I  t0 e5 c, e# g  make-current one-of intersections
5 P, A  p; b3 [! s+ X  label-current
) q' j# \  P8 n8 _/ r. L) ?. O; q: Z1 g4 c% @" n3 q
  set-default-shape turtles "car"
; @- |( V* ?8 F) `8 x
/ W8 X- G8 h* i0 E9 S( ?; w/ V  if (num-cars > count roads)
6 F! X/ k- {. x' s: f# [, U& U  [
5 j' ], P- e3 ?6 Z0 T+ V7 Z    user-message (word "There are too many cars for the amount of "# O* z7 {% y: V0 f* H
                       "road.  Either increase the amount of roads "! w( E" o2 m8 N" g2 l0 M
                       "by increasing the GRID-SIZE-X or "
  }# x& j. [8 [0 i                       "GRID-SIZE-Y sliders, or decrease the "3 ^7 s1 C2 j9 [& i8 j( ]2 o
                       "number of cars by lowering the NUMBER slider.\n", ^2 M/ V4 a8 g3 d3 A8 o( u
                       "The setup has stopped.")& t% X" n* z; _' T
    stop
8 {8 F, r. Z8 F' M  ]
7 E  j+ `# R' `, m3 ^% R2 H9 w2 Y- z9 k  T
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 b. W2 N+ n5 s3 |. G7 b, I  crt num-cars
6 y# y1 A3 J) @5 J2 q* E$ M! Z  [
6 I4 a0 [$ a* H    setup-cars# `( K( c' F0 [, D4 D" j$ k
    set-car-color" E% [0 L" t) t& x& O
    record-data
3 e* x. n7 Z4 k7 G" D8 p  ]
- E* z: x8 x+ W, G, W
% W& j) J' z  l6 u, T+ r  ;; give the turtles an initial speed
# N2 k8 o% o0 w( E0 }: F/ b1 T  ask turtles [ set-car-speed ]
  N$ i5 I6 c( [4 ^$ u2 \1 B# t+ U$ G8 C* ~
  reset-ticks
9 r& @9 F8 N  C6 Q# a  y' @end, g. q1 z& `  L: |! V/ y

- l# V4 M  d& }5 J6 s+ i;; Initialize the global variables to appropriate values8 I, ^: V4 e+ o; A% [6 g- ^
to setup-globals9 c* Q' w3 k0 ?9 O) I9 V- _+ ?
  set current-light nobody ;; just for now, since there are no lights yet" z( G. c0 z! ^) n; \8 r6 D
  set phase 0, d% R4 \6 Q" O
  set num-cars-stopped 0
0 P3 [0 i& I! t3 R, p% R5 X- T  set grid-x-inc world-width / grid-size-x
6 w  P- q( C$ R7 A2 s7 h  set grid-y-inc world-height / grid-size-y& {+ B+ b6 d3 ?! B
2 A: }/ T7 r6 F* D
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 C! S  t1 W/ ~  set acceleration 0.099
; q) r6 Y. O$ bend8 ~0 u4 O7 m8 ~) e* d9 C" i
1 K; U. F6 O) M
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& I, P: q7 P, o3 ~" {: v) [$ L9 k;; and initialize the traffic lights to one setting& V" J) ^9 U  j, o& A* r9 [( k. V; i; P
to setup-patches
- ]! ]0 o3 k  G- e; k  W, t7 K  ;; initialize the patch-owned variables and color the patches to a base-color
# f3 B0 w8 J( L* I$ N0 c% D  ask patches
9 ~" Z0 o" z+ T  [
! W& a0 A& N3 L. [- W    set intersection? false
3 z  l- v$ I6 n% t/ h    set auto? false; B7 W# I2 l) w4 J8 x$ A& Y
    set green-light-up? true5 k& f+ q8 ?6 Q: y
    set my-row -1
+ x9 Y4 B( d% I    set my-column -1
/ l! ?8 {. \' H3 y    set my-phase -1$ x" \7 E3 z$ O# h* ]
    set pcolor brown + 30 s7 t2 R0 E/ U: i3 a  h! ]' f
  ]7 ~# s, K6 P( V8 y9 }
/ `) o' ]. n8 J% |- n9 z3 a  _& K3 M
  ;; initialize the global variables that hold patch agentsets3 k) t9 u& U8 L, x
  set roads patches with
5 j* g" \/ w( u( r    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# ~2 h7 ?$ [/ Q( L3 R    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: _* M4 f- ?9 m) Y& N# ~  set intersections roads with8 t# z" O/ N- {0 D
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: c2 o* ?: M# @0 t
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ y3 M/ I) h' J: G3 x
# C5 A6 {/ i5 x8 K% @) K( q
  ask roads [ set pcolor white ]2 ?" z" A- m  }5 ]
    setup-intersections
. S0 q  N" p) [4 W1 k) _2 iend
0 f7 B& |5 w; u7 X9 m. M2 j: [其中定义道路的句子,如下所示,是什么意思啊?% H) O. b: o1 C- J, z2 Q& _, y
set roads patches with
& ^1 a! Z% y. i, |    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 Z' M8 a( u% e. m
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( v8 p* f' L( B. y6 l8 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, 2026-2-7 23:00 , Processed in 0.017944 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