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: 8434|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。) v) U1 a+ ]5 n, T7 a
netlogo自带的social science--traffic grid这一例子当中,
6 D% v0 R0 x+ _globals
# _% Q/ N. c1 Z. R: O- V; a[
; M# g+ `+ t* |0 Q  grid-x-inc               ;; the amount of patches in between two roads in the x direction
6 U7 b2 f% i4 S4 I  grid-y-inc               ;; the amount of patches in between two roads in the y direction! D8 L3 s/ P  O+ V" e8 r
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if; ]& w" u( k9 Q$ ^3 S- {: r
                           ;; it is to accelerate or decelerate. o% ^8 o+ \- x1 Q" P5 ]
  phase                    ;; keeps track of the phase% t" \9 h+ @7 F! D4 s
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure1 R! H7 z( ]( ^4 b6 F. V! h
  current-light            ;; the currently selected light
. ?# Q9 j8 [: D5 a& O' m" l, C0 ~! D. o& F* f. p* @
  ;; patch agentsets
3 p7 m* l& x* q* E  intersections ;; agentset containing the patches that are intersections
- l) K7 {  \7 g7 H$ @; {  roads         ;; agentset containing the patches that are roads0 K3 N/ ?5 h8 j- N" X- O/ Z8 l
]
, i, D  Z# Y2 W
/ i8 w$ I; t8 Wturtles-own
; N3 E0 P0 L  d[+ I" a4 N1 N; s/ P8 P: x8 O
  speed     ;; the speed of the turtle
# v6 p) \7 U* d9 E  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
6 N3 R8 C7 _$ g  wait-time ;; the amount of time since the last time a turtle has moved$ l! j) W9 d; h+ S" A6 v0 h" p# E7 F
]7 g0 q; M! n6 p* u6 Z
! ]# N5 j" R, P6 d6 L0 M2 y: _% S8 `
patches-own' i& n* G" F4 V$ @- a3 `
[5 |! C' A3 W& b" ?7 s, t/ O0 ]% F& A
  intersection?   ;; true if the patch is at the intersection of two roads+ n( N5 H" J" W3 r3 o' T+ z
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
/ ~+ `) [! C  {6 F. r- L0 z                  ;; false for a non-intersection patches.
7 F6 a* ~" w9 B; m  my-row          ;; the row of the intersection counting from the upper left corner of the
. F# M, `$ p/ D1 x                  ;; world.  -1 for non-intersection patches.
0 F0 }4 [$ R. I- P7 X  my-column       ;; the column of the intersection counting from the upper left corner of the
2 s( B, D8 ?  `' l! k! w! H5 S                  ;; world.  -1 for non-intersection patches.2 l: {: `" h! Z& m5 i- Z
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.1 f3 g7 a5 q5 C/ J7 @0 Z
  auto?           ;; whether or not this intersection will switch automatically.; h8 l3 M4 O1 M$ P* @' M
                  ;; false for non-intersection patches.! h3 d5 O5 n$ O/ @: D
]
) b6 P0 f/ F/ d" F' f0 g; T. w1 n( u& m; ^/ a( T, _2 g

* `" _% r, P2 M;;;;;;;;;;;;;;;;;;;;;;/ m8 [7 Q7 L. l( J! x  H
;; Setup Procedures ;;7 o5 `& S% D4 |5 u  E
;;;;;;;;;;;;;;;;;;;;;;3 `+ e! M5 ^: h: H& H% C" L' U
, |9 O; p# w* i1 t
;; Initialize the display by giving the global and patch variables initial values.
# E$ y7 F& m& w/ V3 o;; Create num-cars of turtles if there are enough road patches for one turtle to7 K# u+ U$ l9 \+ Q, `
;; be created per road patch. Set up the plots.
. p3 w: v0 P4 l) B3 b# ?: d- ?to setup! w0 m: V( u/ ~. h
  ca
: w) _" j, J' S: k; S+ f  setup-globals
# A2 p$ H$ W4 a4 [$ o5 v: l$ N! c0 \0 W  o: n3 C* y
  ;; First we ask the patches to draw themselves and set up a few variables
% G4 \& o! u: O  \) t6 B$ W  setup-patches
+ C) A1 F* s& l3 H0 {- L  make-current one-of intersections5 J7 s; ]+ Z. e" }
  label-current- V0 L6 `7 e9 U) ~: i
3 N2 m* g! B1 \- x1 F
  set-default-shape turtles "car"
& V" l; v5 u& K1 A
) U* Z! {1 _, @. e, \  if (num-cars > count roads)
' t4 K& \5 I! `: L  [
" r4 n* }/ c* z3 z  O    user-message (word "There are too many cars for the amount of "
" k5 ]. c/ I, E2 n* K' s9 a! ^                       "road.  Either increase the amount of roads "  L, d, k; {- Q* z: K! y
                       "by increasing the GRID-SIZE-X or "
, q) ^- H3 o  D7 `                       "GRID-SIZE-Y sliders, or decrease the "
& ~* [7 F" o2 z- A% H" P  ~6 g                       "number of cars by lowering the NUMBER slider.\n"
' T" H- b* A3 B' n  p& u                       "The setup has stopped.")
5 a4 p0 G2 H$ V% g1 x$ c3 Y# W    stop" G) m, {7 V6 f% L1 y
  ]/ r& h3 i& C7 q& `: L

- ?% z: D% I! J$ f  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 |! X* R* `% L- L  crt num-cars6 {+ {+ K4 _6 P5 s
  [8 m' D* Y. }- U( a# i7 J* A$ [1 y
    setup-cars
4 A9 s! ?! V! {: Z( F    set-car-color
* [7 L- B8 S) y* O8 W* }    record-data/ r% h: i4 H9 H( p3 H
  ]
+ N; v3 p6 s  Q! N' Q& f6 ?5 b" k$ p+ v. ]1 C; H: x, B$ P: t( |
  ;; give the turtles an initial speed$ s4 \9 W: A  t
  ask turtles [ set-car-speed ]
9 x) d5 H6 {6 N: m4 P* ]) E9 N! G. @
  reset-ticks( i" w8 b! f/ s: w2 }+ l
end
5 L4 _8 T$ z7 u' I% |
6 V# a2 K4 n6 G, f! e/ ~;; Initialize the global variables to appropriate values
+ h/ C# A) H, Pto setup-globals
6 R4 J2 ]( B: d( S. T  set current-light nobody ;; just for now, since there are no lights yet
9 @* z0 l6 e' ]' b9 ?! ]% {1 v  set phase 0; s2 M* c' @5 U3 k
  set num-cars-stopped 0
4 u  N5 p4 M1 ~: e5 [( d* W  set grid-x-inc world-width / grid-size-x
2 F0 c, K. e/ q+ }  set grid-y-inc world-height / grid-size-y( X) c+ h5 J- ~" Q2 @& N( R

2 Y/ Y4 e0 [% E/ ?: d" @  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary; v* U1 z" l3 I
  set acceleration 0.099+ _$ ^2 I$ g/ p4 ^4 s2 P
end& `& T' g9 G( n9 d
2 i; @' S1 T9 j& C+ b. R2 Q, V' _
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 O" V5 U. n3 Y$ K& ?  `! [;; and initialize the traffic lights to one setting2 K2 o2 m' H8 D1 s9 \7 C
to setup-patches: G3 h/ x; R/ u
  ;; initialize the patch-owned variables and color the patches to a base-color
9 W7 R0 V" L; k1 u* T  ask patches
% f3 ?) w* A) {- i, g! c# s  [7 [& X5 z) E1 p* C. ^
    set intersection? false
) W: ?$ R6 I& m    set auto? false% b! a. j- Q4 O6 ]/ H
    set green-light-up? true# Q0 y9 @6 X4 B1 b
    set my-row -1
, r4 N% {' [: |    set my-column -1
" j% F+ P+ R  |2 S& k    set my-phase -1
4 w4 t+ K6 G, h. D    set pcolor brown + 3; p3 Z6 M/ \  ^1 z$ N
  ]9 a$ v  C8 _; e! B$ }+ |" L* X* l5 B3 {

/ n! M  y9 u, d9 Y  ;; initialize the global variables that hold patch agentsets- K7 I" P+ x: H" g& m/ Z; p
  set roads patches with
# N# z. C" e# v% u; G3 c% y# y. _    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! r/ x# J5 L; |* Q+ N& i7 r    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 m, H& p% M$ j; k! R
  set intersections roads with: Y* P2 ?5 b# Z) {
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- N2 M4 e* b( d8 Q
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ r  |" Y( H* y& v
5 c2 |* o, G" |' g! c1 X' u9 D
  ask roads [ set pcolor white ]
) ?% e3 d+ X- B1 v' N4 t3 m    setup-intersections
: X- _( z# f- Jend8 S$ |- Q0 N1 G9 L, ^0 v' ~
其中定义道路的句子,如下所示,是什么意思啊?& d- F6 U0 p" z
set roads patches with
7 m6 C+ D: I4 \# x    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 E  r8 O/ v2 Q% t4 ~5 O
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 p8 ?& t0 i" x' v/ m1 z
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, 2026-2-18 00:20 , Processed in 0.014391 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