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: 7471|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 d% A! w5 H0 K4 h: N. T
netlogo自带的social science--traffic grid这一例子当中,' p) O6 \0 q& b7 \
globals* r! y2 j" ]; D. Z
[
) h5 k* R" L. @7 A- J  grid-x-inc               ;; the amount of patches in between two roads in the x direction
7 c" j7 l5 V. q6 A  grid-y-inc               ;; the amount of patches in between two roads in the y direction- L' Y0 _8 Z3 g. S
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if, \/ @6 L% D" l+ z8 i( B$ I0 L
                           ;; it is to accelerate or decelerate) h/ `/ L! }6 L( g
  phase                    ;; keeps track of the phase- u/ ?# H- A& D
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
5 ~4 e5 Z8 m$ L8 b. S. F  current-light            ;; the currently selected light
, [! m' Q, W$ g2 J2 Z1 f
% @# W9 {2 x6 }  ;; patch agentsets
6 h- U4 U! r6 c8 X- h  intersections ;; agentset containing the patches that are intersections% M, G) }5 U& {
  roads         ;; agentset containing the patches that are roads/ x% R1 u. l0 b1 [2 R7 `+ l
]
5 F8 S" t4 e, B' K! e, P$ b7 e8 |. x' i" |( b, ~' y
turtles-own
2 [' U# N3 G0 t1 ]' F[
- b9 x( g% o7 m: a) k2 t  speed     ;; the speed of the turtle; n- U8 R! ?  ]! `7 t
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
& f2 u- J0 o& F- Q* ], a$ P  wait-time ;; the amount of time since the last time a turtle has moved$ K& O( q" e. U( b$ t
]. ?4 U: ?& L  ]7 }1 l  o( i  a
1 W: ~/ x0 Y( j  U
patches-own+ A4 [2 {) `" `: l" y* j
[3 u# p# a: V0 v  n3 _& n
  intersection?   ;; true if the patch is at the intersection of two roads3 A: s& m9 }( J3 J9 P
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
# }5 h( t: y4 C/ Q% d' F. K& ?- V                  ;; false for a non-intersection patches.5 N" S! ?! e3 Q  y
  my-row          ;; the row of the intersection counting from the upper left corner of the
: b! e4 m* j& A9 _+ N' Q                  ;; world.  -1 for non-intersection patches.% H+ T+ u1 V7 ]6 |3 P
  my-column       ;; the column of the intersection counting from the upper left corner of the" G* B  `. `( I7 ^8 |
                  ;; world.  -1 for non-intersection patches.& }& e4 W/ |- k: w
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
/ H& r0 H$ B2 j4 D# J9 `  auto?           ;; whether or not this intersection will switch automatically.: Z) u  {+ H  S0 R5 _9 |6 G
                  ;; false for non-intersection patches.
! E; O3 T9 u' ?" h& ?2 ?# K]
7 F  ]/ k! R8 i3 b7 t  Q% p7 T) ^/ l, t+ v2 D1 a

3 \4 O% T$ l7 x9 z( ?. V;;;;;;;;;;;;;;;;;;;;;;. y6 N: G9 V, k
;; Setup Procedures ;;
2 V, \/ w0 F2 j! y  j+ r% s;;;;;;;;;;;;;;;;;;;;;;; d9 K  n% C- b* k

$ y2 C5 D- b3 I% l;; Initialize the display by giving the global and patch variables initial values.
) K3 P4 ]( I8 i% ~1 S1 s;; Create num-cars of turtles if there are enough road patches for one turtle to
  g9 r# _, h: X+ C;; be created per road patch. Set up the plots.
: h/ ^( J. Y( a, R8 r; rto setup
/ X( F5 b( `! _9 v( B6 [# X2 W$ {  ca
- ]% S  C7 r5 }! H( |. f  setup-globals& e" e9 I' K7 Y2 i9 F9 y0 ~

/ @+ k' K/ _  c$ H" {' U! f3 d3 u  ;; First we ask the patches to draw themselves and set up a few variables5 n7 B4 j& v6 D- `7 n9 v
  setup-patches
/ |6 a, P9 L5 M& b) H0 e  make-current one-of intersections
6 N4 W, B/ F; z1 R  T  label-current6 S: g# ~- p  h% ^' e8 B/ I  P

6 a! k, m$ g- j0 \9 {7 o  set-default-shape turtles "car"5 }) {# `; |3 `. I( K" O8 V
# H/ M/ L0 {2 M0 u- t
  if (num-cars > count roads): W5 t4 \1 Y1 I# V
  [. C3 c' O. j1 x/ b( m. y) \4 s
    user-message (word "There are too many cars for the amount of ", _1 `  @3 k( m4 G! h" K+ q
                       "road.  Either increase the amount of roads "5 M1 ?( s, c+ J' b
                       "by increasing the GRID-SIZE-X or "1 D# Q( h" }2 Y: k$ k1 U8 Z  K) ]
                       "GRID-SIZE-Y sliders, or decrease the "+ ~" M! v3 m$ k4 [' \
                       "number of cars by lowering the NUMBER slider.\n"0 k! Y# D+ y' `# O1 i
                       "The setup has stopped.")
: z, [% e: t: S/ x* ?2 V# j    stop
& ~0 [; s8 u1 |' u# w" U  ]4 C* c# @9 I% e/ X

3 a4 [* g  \" L' X4 ^) E7 j  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 T, ~" E9 I, l- s; f; D& k
  crt num-cars
, E, Q! e+ K& y  [
: `% c3 `, K1 s- z# F: c7 J# m8 S    setup-cars
9 x5 |' {7 D. l$ C) H    set-car-color
! p7 O; f9 z8 b4 r    record-data" o) t; r: X( e2 h% {
  ]
/ _7 s) `5 o3 o0 e0 \' w( p2 M5 Q/ J3 o: c* _7 G" f- q
  ;; give the turtles an initial speed
) {- Q+ y3 ]; I$ z9 o# }  V9 W  ask turtles [ set-car-speed ]
, S5 L9 [- C3 d5 i! A
6 A: r& d6 a+ T+ `  k; T# g  reset-ticks* _, `6 {/ x" u! m- \: [
end
: K3 {* a" E9 ^1 f& f. ?9 M" r3 y5 ~! w* y
;; Initialize the global variables to appropriate values
3 j# K6 N  R0 {' ?6 h4 ?( r. R% Oto setup-globals
4 ~9 R4 V$ y. ^  \" h" e  set current-light nobody ;; just for now, since there are no lights yet$ F+ G! p6 `- {% Z" ~2 k$ Z- J
  set phase 0
$ K2 c6 @$ `2 r% K  set num-cars-stopped 0, d$ \4 G5 S; E9 v
  set grid-x-inc world-width / grid-size-x8 q" ]- p- G5 ?$ A
  set grid-y-inc world-height / grid-size-y5 Z! R: y6 q2 o; c9 G. u

' ~) E% R- K/ O& f  x  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) Y" C3 C5 T& D! C$ f  set acceleration 0.099) K( s6 B! M5 E( b0 X+ |- s
end* Q5 G# [$ w5 c$ V* \# {$ a( [4 u! i

- q8 i7 {9 t" ]* P7 |( Q+ C, Q6 e. w;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 Y2 u+ b, m6 Q/ }  O; H: C;; and initialize the traffic lights to one setting
- q, q5 a8 K+ Ato setup-patches
* l' q3 F1 D: u  ;; initialize the patch-owned variables and color the patches to a base-color
1 e* Y( Z( L3 v9 {  ask patches
: U, k# A1 ?% B3 [  [" y/ [6 g/ E( q, I- |
    set intersection? false
0 Q% M; u  q; ?5 z5 _, J+ C    set auto? false( Y3 Z: U  v0 r: `. B
    set green-light-up? true# X8 f  i- B; M  u; S3 l0 J  b
    set my-row -15 p7 d$ |8 f9 y
    set my-column -1
9 F; }- i$ h$ V1 o- t6 j9 u    set my-phase -1
0 D& ~9 ?" Z8 i. Y+ L* u    set pcolor brown + 3/ B& O8 t9 X; I/ C; x/ e* q. v0 l
  ]' _! u& Y4 f/ y' M2 {# W# ]9 \5 Q6 W
' Z) ]: e; T$ h. r
  ;; initialize the global variables that hold patch agentsets+ ?$ K/ v6 Q2 g6 i! c
  set roads patches with; g* M# C0 f( K) l' o$ s
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 q$ Y- v' c" S6 p$ {    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) ]5 Y! k- j2 y0 [9 o+ ^  set intersections roads with0 X+ I7 q: y# d8 @0 o- N
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 o$ d  D" f- D) M& w
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) {2 I6 k3 K' m( S* r; H# {/ M
+ i  b$ H2 e, P' Y7 J5 w  ask roads [ set pcolor white ]0 S) q7 _5 t! E( a
    setup-intersections
3 s' y$ V" `- d9 lend
- u, x* u/ V6 J其中定义道路的句子,如下所示,是什么意思啊?1 F5 e0 }& ^6 K
set roads patches with
- h2 v% ]4 x% B' ^* N* j    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ {* |5 r/ H4 T6 g. d/ B0 ]; P    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 F& T2 ]$ h3 I8 C% ^  @/ 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, 2025-12-18 06:46 , Processed in 3.146537 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