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: 8070|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。# _* T# {" O8 l1 B9 `
netlogo自带的social science--traffic grid这一例子当中,& [8 g6 b0 k  o$ \
globals0 C( ^/ j8 j% o
[
) g2 E+ W. u0 K) _$ A$ w" L7 d  grid-x-inc               ;; the amount of patches in between two roads in the x direction3 x9 e! E$ K' f' |7 T
  grid-y-inc               ;; the amount of patches in between two roads in the y direction2 V! N: d  @4 i4 ~7 d( g" A9 ?
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if) b  H- _9 a* |' f3 E
                           ;; it is to accelerate or decelerate3 s% \) G# C! M+ R/ B
  phase                    ;; keeps track of the phase
4 B1 E1 Q' w* O# t+ p  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure/ R" y9 M" ~' M) \9 f
  current-light            ;; the currently selected light3 D+ ^. ^8 e5 X/ m
8 V( ]: ]1 `$ \' d
  ;; patch agentsets3 j7 E: A' W3 E# V) E) v6 x" P* G
  intersections ;; agentset containing the patches that are intersections
  U$ d$ L5 q* ?  H/ b. L! E  roads         ;; agentset containing the patches that are roads
# A- j; j5 E* q  L8 R' }]# T0 V0 J9 \$ U

3 d* S; f, h6 \$ S8 J# ~6 d" }' nturtles-own$ R5 |3 G, q* y4 [9 Q4 L; r
[: g/ @, w6 O3 D' M. J0 [4 S
  speed     ;; the speed of the turtle
. E1 S1 T- F1 x9 Y5 D, b: q  up-car?   ;; true if the turtle moves downwards and false if it moves to the right) I" H9 I7 O5 V9 p4 P4 w% X/ K
  wait-time ;; the amount of time since the last time a turtle has moved
5 s7 {: y, g$ T]
* e# d- }% h2 g! D
1 Z/ c9 M5 R" O3 X+ fpatches-own
+ v: q9 N2 M; M, }1 Z9 h% D8 \1 k[6 N( K3 h; s8 Y( y" I" T* |3 M! R
  intersection?   ;; true if the patch is at the intersection of two roads
2 j& Y) L6 w* [: c0 s) V# O& l  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
! y8 q* m4 r2 Y) k3 c, W                  ;; false for a non-intersection patches.
7 y" O1 L# _$ T. K3 v" r- J% X  my-row          ;; the row of the intersection counting from the upper left corner of the9 h9 g& T9 I9 p5 h. J# Q, k
                  ;; world.  -1 for non-intersection patches.6 i9 m; U! X# q. ^. P
  my-column       ;; the column of the intersection counting from the upper left corner of the
/ A! q; |+ K6 a2 n- ^" e9 O: Z                  ;; world.  -1 for non-intersection patches.
2 ?4 J" E$ X& G+ f2 r! s5 H' _  _  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
) V& y+ b/ U; G2 K  auto?           ;; whether or not this intersection will switch automatically.
, l1 Q. c2 T( b! Z3 ?) X                  ;; false for non-intersection patches.: J+ M. [4 ^# s) W- q9 \! U
]
; K' o/ R0 @; A/ Q# x) u* N( J5 `% t) W2 w
+ O2 i* b2 _' B, S9 g+ g; _7 J
;;;;;;;;;;;;;;;;;;;;;;+ b  x+ @" G2 r! D2 u% h; |
;; Setup Procedures ;;7 O# ^) T0 Y1 v8 i
;;;;;;;;;;;;;;;;;;;;;;
  D5 p% W) V( [8 s( \
' q% G% `7 r' a. O) O. j;; Initialize the display by giving the global and patch variables initial values.
$ h' h& i& K4 H- t2 N;; Create num-cars of turtles if there are enough road patches for one turtle to
1 ?- _& b+ A8 K# U: w7 o. |;; be created per road patch. Set up the plots.3 O  ^: t" k; X
to setup7 Q+ X  F! R9 V% b/ L
  ca
4 H) o5 Q1 R& K" i  W1 ~  ]/ ~  setup-globals- P- I  U7 b8 v  K; E  s/ N9 `
( A9 K; T3 x' |
  ;; First we ask the patches to draw themselves and set up a few variables8 [0 E% k) E: U# B* M, h& z, N
  setup-patches' `9 H% ~& a" I) q4 P3 p
  make-current one-of intersections% F( R+ m) l1 R4 [% T4 n
  label-current' [4 j' A3 f# |8 T

4 e7 }8 [5 E. ?2 ^. Z8 r0 Z6 l  set-default-shape turtles "car"% O9 A3 I& l+ I' w: \

. a* m1 D7 G3 S  {4 W$ q5 L  if (num-cars > count roads)6 w# N+ ]0 R) l
  [, ]& K* b7 j( k/ J. X: t9 h; x
    user-message (word "There are too many cars for the amount of "
; |+ ~, @7 Y9 y; f. d                       "road.  Either increase the amount of roads "
( t- j# H1 ?+ k* f  H9 n0 h                       "by increasing the GRID-SIZE-X or "
8 T8 X) T7 U% E5 E                       "GRID-SIZE-Y sliders, or decrease the "4 O4 R* ^; q( s2 Q. ?
                       "number of cars by lowering the NUMBER slider.\n"
% I- H$ d7 Y( ]                       "The setup has stopped.")
- T  }% Y9 k, [% S    stop
# a& S# |; C1 l% i7 e' h4 i' ~  ]
  o7 N' [' F! N$ q: X% H
7 v8 Z1 o4 y/ B  N' D2 H/ [  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 ]! {) Q, u) ]- @
  crt num-cars
, z( d) b: P5 d6 S- x  [
1 X3 Z- ~: M8 b# f+ ]9 C" F    setup-cars: I# \. j* T! C4 R
    set-car-color
- B% j" y5 v# ?4 B; o7 Y0 S! D' }. I    record-data4 h1 E: `' K6 u5 g
  ]5 r, {' `0 _$ i: G7 K/ Q
, [4 A9 v; O& C5 ]6 t: m
  ;; give the turtles an initial speed
( b( s! l/ k4 u  ask turtles [ set-car-speed ]
( J& Z6 R' b4 W" h0 W$ y! [% r; S0 S- g9 Y% N* p5 t3 w/ P3 h+ y
  reset-ticks
, Q: F% @4 z" @1 yend
( {- ]# w% b. X9 v
) M& e* w! W: a3 J0 m;; Initialize the global variables to appropriate values
% K' f# b4 [6 ~) m# x; Kto setup-globals' |* A: U; z: X0 h
  set current-light nobody ;; just for now, since there are no lights yet
. _% S/ J/ D* t- c+ e  set phase 0
9 T. t+ c. H+ N0 o* p  set num-cars-stopped 0, r9 E2 X; c4 s- m
  set grid-x-inc world-width / grid-size-x$ @! v8 A0 f) d+ ~/ O3 F# N
  set grid-y-inc world-height / grid-size-y7 Z9 ^3 o/ a- F! y' L( V" V
! Y2 a- l9 r$ p
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; |# M' Y7 [7 _$ C2 F1 |7 ]+ [  set acceleration 0.099( k5 ~( V+ T$ d0 U. k5 c: a
end
& \$ b$ D% E7 U" l' v- s% R; t# U" y1 T
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 C4 J. _0 D1 V3 z;; and initialize the traffic lights to one setting
4 F! _3 a! W0 ~to setup-patches
+ y/ n% f: A( Q# v7 f* \  ;; initialize the patch-owned variables and color the patches to a base-color5 u; ]4 ]% N$ b8 u3 z/ |# i' a
  ask patches
+ y) C4 N: M/ p% p5 w  [7 i" B+ [/ q5 s! n4 _0 @( u
    set intersection? false
6 ~# g# k$ n. J5 s# l    set auto? false, s9 s; N8 i. h' d* P( Y# @5 ~) ^
    set green-light-up? true
0 {+ b. |, k, q3 N, d    set my-row -1
* a6 H0 F7 M- B  Y( l; \    set my-column -1* J* V/ i& P4 }0 w2 {8 z
    set my-phase -1
2 \! s6 G$ b- [9 _; y" q    set pcolor brown + 3
) }% v3 m1 h$ ^) [) L9 y/ ?  ]
! F( s, E$ q) i8 @& E3 \
1 `" e& s- m( m  ;; initialize the global variables that hold patch agentsets) c0 h; |$ X. x2 z
  set roads patches with2 N# q: l- p2 S  `, z& p: g# t
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 c# t/ P' p; w7 T
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 I4 L- i7 o; s2 f! {* v8 ~
  set intersections roads with
% e  t9 g, D3 Z; t1 Y" X4 x    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' |0 l( }' J. L. j7 H  |
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 V; F1 w6 V1 w( }1 H% E

% Y* t3 ]/ @6 Z# m! }' |- D# C. i% G  ask roads [ set pcolor white ]3 w. K0 K# k( B0 W8 e. l7 C
    setup-intersections
1 U6 A) ]/ E* ?2 D5 \$ K3 hend
9 O3 D- Z5 ~: M$ |3 g/ _2 w其中定义道路的句子,如下所示,是什么意思啊?
9 M: @: _6 W% q' w set roads patches with
9 l( l* `$ W& ~/ z5 d6 d    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" I& W3 W; ?/ J$ U
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 _% L; ^, O% N$ F- c6 ?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, 2026-1-30 10:47 , Processed in 0.016618 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