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: 7576|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。
. J5 P! g' z7 B( R9 Q5 r' s7 mnetlogo自带的social science--traffic grid这一例子当中,0 A; ?% c5 j! {6 ~4 ?
globals! l! N1 r: c3 o! |
[' H, [9 U9 u) R+ W' z6 R, Y
  grid-x-inc               ;; the amount of patches in between two roads in the x direction* C5 ]( ]$ x, j# |: R8 y
  grid-y-inc               ;; the amount of patches in between two roads in the y direction! @& F2 f( X: A" p) P
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
" V5 d, D9 Y9 q$ k                           ;; it is to accelerate or decelerate
. P# @- I- P/ z  phase                    ;; keeps track of the phase) Q. ^3 O5 X, D; T
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
; \) H6 a* R! M) W' w) F- U  U  current-light            ;; the currently selected light' N) Z8 d% e+ x3 F4 r+ M
/ \( h- C9 c. X# F! N
  ;; patch agentsets0 x* Q! V. {, h/ b  T5 B0 _+ o
  intersections ;; agentset containing the patches that are intersections& T5 B2 Y( N- w8 W+ J9 M+ r/ S7 K
  roads         ;; agentset containing the patches that are roads) k) u' X+ W' ^' @
]9 c, A- J. a8 I. Y2 N: W4 _
  P, ^- D9 Z/ O* D! g3 Y
turtles-own
+ j, i; ~& W2 O- S7 n2 L" B[
. P  y0 R! O7 h  speed     ;; the speed of the turtle
3 Q, j, x" K, k5 S  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
2 g0 }5 a' r; Z& Y. f  wait-time ;; the amount of time since the last time a turtle has moved. Z8 h0 _9 Z7 f3 k+ I
]
: Q5 F4 @5 V+ l4 z+ o$ L# D4 K; }) q
patches-own+ e- a; \4 R: k0 L) J- u4 F  S) r& |
[
" w, c: S: Y: B  intersection?   ;; true if the patch is at the intersection of two roads
3 b  }8 d$ m) E, _  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
8 C- Q5 Q. I$ O. L3 A' h                  ;; false for a non-intersection patches.
& U  f, Q* {* ^* x  my-row          ;; the row of the intersection counting from the upper left corner of the4 H- B% V* }: [
                  ;; world.  -1 for non-intersection patches.
2 ]% ?* P. S4 Z3 N- w  my-column       ;; the column of the intersection counting from the upper left corner of the; ?! i, h$ Z* B
                  ;; world.  -1 for non-intersection patches.) Y3 m# `1 \$ S4 s
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.* A! x' i' ?, s6 s4 K5 s: P6 f
  auto?           ;; whether or not this intersection will switch automatically.
# |/ k3 g- M- S, e  j* R                  ;; false for non-intersection patches.2 O3 i: H# K5 {9 {! ]
]/ F3 f4 F7 s9 H7 a

8 L# s# \- T% `0 c. q, k( F  l0 ]7 }. v) d& {* n
;;;;;;;;;;;;;;;;;;;;;;
+ I% Q9 m% n. u( p2 x" ^# c;; Setup Procedures ;;4 w( s. f) z/ u0 e( e0 b
;;;;;;;;;;;;;;;;;;;;;;
: Y! f; J9 ~& L; e0 O0 T* }7 K
  r. t8 E# p( c4 s4 K;; Initialize the display by giving the global and patch variables initial values.
" e  z) c. U) q2 h+ f;; Create num-cars of turtles if there are enough road patches for one turtle to
' a# L, l) B: x8 X( I( ^;; be created per road patch. Set up the plots.
; @/ m6 P! N8 r; Y6 d2 s  u* Nto setup" m! D' E& y0 Q* g
  ca0 n5 s3 d  R7 j- A0 |$ l' c9 f
  setup-globals: ~3 t8 S- G2 g) m7 `0 q8 }

* ^1 l' s( ]& X' ^! [  ;; First we ask the patches to draw themselves and set up a few variables2 [4 }2 b9 T6 Z$ A/ @* D. [' T
  setup-patches' _4 ^! j: y0 B/ U6 C
  make-current one-of intersections
% f, m5 Q8 s3 G3 _: @5 r  label-current
  J0 I+ p8 K# L/ b) t6 F
, ~) e3 d  A" b) W/ P  set-default-shape turtles "car": U$ B4 Q* x0 B  C: U

# A. V' w) ]; w0 l' x% r3 Z  if (num-cars > count roads)2 K0 y7 @- c! z$ {
  [
6 |" f& t  G' M% M1 _* g. a$ u5 l! W    user-message (word "There are too many cars for the amount of "
/ l) z! v% C+ @                       "road.  Either increase the amount of roads "
; R8 o3 y5 w. m, y; f/ C6 H                       "by increasing the GRID-SIZE-X or "2 m" L! f. c/ f- L
                       "GRID-SIZE-Y sliders, or decrease the "
9 C7 M; s6 a# @2 }( l3 B/ p$ J                       "number of cars by lowering the NUMBER slider.\n"
' }- `' p8 M4 R+ w! r4 ]- D                       "The setup has stopped.")- R  L8 y/ A" W+ z6 x
    stop, ]! H. Q# J, U+ k+ Z
  ]3 m, M; T% `: a. e

( b+ r' G( k# T  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 I0 z4 U% f% K9 b4 B* a0 `6 |% R
  crt num-cars
4 ]+ @% j5 q) |  [
; V" x6 _4 e# c    setup-cars: i9 ~0 G' J& g# }4 @- C; K
    set-car-color
/ _( U# x6 ~) V" C    record-data& l9 g7 p' p. t6 _
  ]
: C: O1 g8 R* X& v. u. h2 Y$ ?0 @5 Q* [: Z" R2 |8 ^$ C
  ;; give the turtles an initial speed
; F1 N4 E8 c% C, n" G, v  g; Y  ask turtles [ set-car-speed ]
) O* \& m0 `# |7 O) p2 S/ F7 P7 m6 @) a/ U. X1 p
  reset-ticks2 F- v- I; D0 E6 F
end
, S2 m: L- Q! w. s, s' A/ A8 x; f1 K
! X+ B/ Y4 V5 J;; Initialize the global variables to appropriate values
& B  U8 p2 [; i; Oto setup-globals" ?: D# \& D) w# \4 H
  set current-light nobody ;; just for now, since there are no lights yet2 h8 b! ?. f) N% V2 D% O
  set phase 07 d. n  M% e( {) {
  set num-cars-stopped 0. u$ M( V8 F9 m6 c
  set grid-x-inc world-width / grid-size-x
; f! q# o3 O5 ?- x0 _/ |8 k1 j% ~  set grid-y-inc world-height / grid-size-y
1 B8 w- m7 Y! }0 a+ j9 w8 [
' e" k- E' P( Q: i! {. @& g; k4 [# F. _  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ o8 y: b# g9 H* |  U8 d5 L
  set acceleration 0.099
, {9 x; c3 s5 [9 D. J( ^end* C# i% n) R4 ~% q
, }  \- s( S& P7 L2 _
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 u6 r9 R5 v; a4 B;; and initialize the traffic lights to one setting3 Y4 [! O+ x- G% x8 ]9 _
to setup-patches( e- Z, C/ O2 I9 ^$ W5 H
  ;; initialize the patch-owned variables and color the patches to a base-color
: w, J) @' n& S5 s  ask patches8 X" ^  F! D6 u) j2 y
  [
1 i- F+ ?5 j  H2 N0 W5 o. _# ]$ d    set intersection? false
7 K! W7 D, Q1 N1 v3 J7 I! g2 c    set auto? false
7 L. Q2 @$ A3 w4 R    set green-light-up? true
: Z! K* T4 t( s" O6 z5 r    set my-row -1
0 v. D6 b% ?2 \1 n. S1 Y    set my-column -1. P$ H& v" K, u( ?' T' M
    set my-phase -1
# P! s' o$ K0 \8 ?5 Q  o    set pcolor brown + 3
: x$ E! B' n/ v: A& u& Y  ]
- f) K/ ]* N* \4 ?3 Y  C# i7 b
$ `! `" j: Y# B* b  ;; initialize the global variables that hold patch agentsets
3 @' b8 F8 W: X+ F) }  set roads patches with
( L1 ]4 Q3 ~4 Y. z    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 ~. I; m' n- W/ O( w: K
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ Z% P; r" J( N* g
  set intersections roads with9 h: r+ ~) J- M: e
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# X* P0 O* m& n) {
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 I1 j2 n1 x* u! c/ e$ R

; c' H: _! X  c5 L  ask roads [ set pcolor white ]
0 ?, z; T8 @+ i2 [" m! [/ }, S    setup-intersections! n0 p  y' G3 B3 u
end: t4 ?& K/ @5 T/ D1 a
其中定义道路的句子,如下所示,是什么意思啊?
; [; s$ G2 e% l) N& {, S set roads patches with) T# W+ a- W. P# i6 w- B
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: P! W( K8 r% g, I
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" p/ N/ v* ~7 `2 l- F8 j% j
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, 2025-12-27 12:35 , Processed in 0.014147 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