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: 8127|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# ^/ `, g3 H+ c& g$ j& c
netlogo自带的social science--traffic grid这一例子当中,, K: d3 ]$ G' l" s/ t! w4 x
globals
, F  {$ I/ I: d6 Z[3 \0 e! X; ]* x( T, t# _
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
* [5 m7 A9 B7 U# X  grid-y-inc               ;; the amount of patches in between two roads in the y direction
" Z0 e9 g; h0 V+ H. z  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
$ s7 \* o( G" p+ S$ m$ X0 Q' ?' I                           ;; it is to accelerate or decelerate1 x9 @5 `/ {; z- q% k- b5 f
  phase                    ;; keeps track of the phase, x% Q0 `, o! f. h# @0 c
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
( q% v) x5 L& x5 K  current-light            ;; the currently selected light! G" Q# T7 @9 w" x+ N
+ M$ f1 S% ?3 A3 u
  ;; patch agentsets3 d2 G$ V& f# ]' z2 J5 Z4 v
  intersections ;; agentset containing the patches that are intersections
5 g9 [* G9 l/ j7 e/ c. M  roads         ;; agentset containing the patches that are roads) v7 R6 {" o8 f
]
% ?8 W' n  G- I; a* z: g9 K$ I9 O8 G0 t1 W* G1 G9 d# u7 y
turtles-own  H) f4 o4 E' g
[
. A( u- i$ n% c  W  speed     ;; the speed of the turtle
7 c! `: h7 K, k& |% b0 u5 i  up-car?   ;; true if the turtle moves downwards and false if it moves to the right- R; E! U& ^9 `( x2 [" Z$ }
  wait-time ;; the amount of time since the last time a turtle has moved
7 z3 G+ j9 m8 U; d]. T. Z' E: ?" S8 k- }* p; ?

, |+ t0 M6 ?! J" r' o) ypatches-own  C7 b" m# k3 V% T* [9 E( R
[
% G6 W" Z+ s" ~% k/ d* M& m5 M  intersection?   ;; true if the patch is at the intersection of two roads$ u6 c0 M# }2 p( ?- i
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.( `! X$ J  `9 Q  q
                  ;; false for a non-intersection patches.
/ G* ~6 E5 Z- o( c8 n  my-row          ;; the row of the intersection counting from the upper left corner of the- U; @( y) s% U, W3 i: L
                  ;; world.  -1 for non-intersection patches.
- d/ V* J$ s- |8 ~' `& Q  my-column       ;; the column of the intersection counting from the upper left corner of the2 G( T* J6 S9 A: I: u- z& [
                  ;; world.  -1 for non-intersection patches.
) V$ J5 v. N8 b& Y5 @! n! i" a  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.: L3 c( e6 z' W- C
  auto?           ;; whether or not this intersection will switch automatically." b) L1 c+ K$ ?0 |0 k0 e
                  ;; false for non-intersection patches.
- u; ?2 s  ~) {9 |8 n]
) }, z7 b* M& b7 j3 M# q9 q8 |1 v9 m5 w) V2 M2 P" C: s& f# ~  K# Z

: w2 V" u& ]; E;;;;;;;;;;;;;;;;;;;;;;* j* H' H. f! O% F$ `9 {+ m7 h4 t
;; Setup Procedures ;;& A* n% t* |+ y$ [6 v6 J
;;;;;;;;;;;;;;;;;;;;;;
/ Z3 m" ^( L  ]# H* j3 ]
( j2 K1 {# t- k9 \* s8 @' [;; Initialize the display by giving the global and patch variables initial values.
) d4 m8 A, N" S3 }8 B;; Create num-cars of turtles if there are enough road patches for one turtle to
& C. V6 x0 R  @;; be created per road patch. Set up the plots.. q& ?8 i. ]! K- j' Z
to setup
1 _! S8 B# I, @& J) l# F6 @) f  ca( t( j+ a% P( m7 W9 \: g
  setup-globals
5 H5 ^& k: t! ?5 @% |  ?
7 p7 x4 b* \- C7 W  M. l" t  ;; First we ask the patches to draw themselves and set up a few variables9 W  x" V9 g  J
  setup-patches
- l. o( w+ l6 r; T  make-current one-of intersections
# L7 C% K# G- w7 G+ B  label-current  w1 @" r, O% }1 `- p
" [' t2 v$ E- s1 P/ t. r
  set-default-shape turtles "car": F9 c( E3 S, @3 `: Z  E, w
( G; N7 |. W% D0 \
  if (num-cars > count roads)% h! z2 W$ W7 |1 I! J1 g
  [
; w. \! h) Y* I4 i3 ]    user-message (word "There are too many cars for the amount of "
1 G- V( m0 j3 l$ A- J                       "road.  Either increase the amount of roads "
5 ?5 {2 l1 c; s0 Q- O/ Y3 ]+ ~" j                       "by increasing the GRID-SIZE-X or "
- M( @# a( c" ^! P5 E                       "GRID-SIZE-Y sliders, or decrease the "
- n% ^8 Q4 L9 h7 a                       "number of cars by lowering the NUMBER slider.\n"% c: y5 Y( M' c0 B  n
                       "The setup has stopped.")8 D- Q! M$ C) @+ k4 Y( ?  S1 L4 x
    stop+ e: i0 G/ P3 e3 e
  ]( r5 d/ t6 z* F- @
# R# i( N# i1 ], h% A
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 N2 g8 d) {. m: @
  crt num-cars
- n( q" g8 G1 t5 H4 z% p$ a  [2 d! m& G# ]. b  c8 C
    setup-cars1 Z+ L6 I8 f* s6 ?. Q; h
    set-car-color' _; }: H; G9 J+ P' G
    record-data
8 j5 n- z4 L7 T0 \$ s/ U5 i7 ~$ Q: x  ]
5 ~" _7 R# c, g$ A8 ~" X( i/ g# Z6 B8 ~# Q) S
  ;; give the turtles an initial speed
: M$ D8 u# m/ f6 r' v2 t  ask turtles [ set-car-speed ]
; X# p6 v1 }! I* w4 v# A2 U" {8 h# O( _8 x) Q9 V, L7 [
  reset-ticks6 L8 T+ X* ^2 t) T5 s; e( Y) z
end% e( G/ d% h3 D* g1 N/ }6 [

( L# e6 s) H2 @7 M5 _4 [;; Initialize the global variables to appropriate values
. {/ h, D! O) b0 {9 B+ ato setup-globals# J7 @  @' x0 d5 g5 U5 U& n* H
  set current-light nobody ;; just for now, since there are no lights yet
8 o0 U* ~& E0 |1 H  set phase 0+ }% r) @5 b: e3 r7 {+ i4 l6 a, f
  set num-cars-stopped 0
/ l- v  l+ k: I* W5 }  set grid-x-inc world-width / grid-size-x
, B' x. M3 }  ~" b5 [  set grid-y-inc world-height / grid-size-y
# x: j& l" V$ J- S0 O0 H$ `# M4 D3 A$ Z0 ~6 M
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
: V. s! W( n9 A) y. {& a+ _  set acceleration 0.099, n( y* k0 i8 t. ]
end
" h4 z) L2 g5 c$ w# V# Q0 E) l7 N' I
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,/ K: d! C5 X! ~7 A/ R" a" Q
;; and initialize the traffic lights to one setting$ d3 s! _2 x& ]
to setup-patches! C4 w7 V  ]  H- W2 P+ o4 k
  ;; initialize the patch-owned variables and color the patches to a base-color$ J* y6 p# H0 R. M; e
  ask patches; H+ S( U7 |  R1 i7 y) T5 D) V
  [
, L( Y# O. ^9 @1 i9 [    set intersection? false3 \& Y8 S" |! B8 m
    set auto? false+ k6 k; N! R, s; ~. H
    set green-light-up? true, f2 j. H: Q, S; K& i* x, l
    set my-row -1
! [5 t: F- f/ F. Y6 m; x    set my-column -1
& f) M; B+ O# A7 k' I- N    set my-phase -18 H2 F# X; `$ \
    set pcolor brown + 3  d* _$ ~7 r( `2 N( k
  ]
4 J+ H0 x$ [0 I2 l- V/ O0 ]0 }: R; ^9 d6 M, h4 r* k+ U
  ;; initialize the global variables that hold patch agentsets
) \, Q, [/ O4 V! z  set roads patches with
, A( G0 h* [$ [0 c    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* I# V2 y, R3 Q4 ?
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 E' h& X& U% D. a% @, u: r2 \
  set intersections roads with
$ K, w: e9 K% z    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 j! L+ Y8 |, [3 p+ T1 ~' Y$ ~( ?
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ k9 y' @2 }. y5 s  j
- @& y  ^/ T- ]- O3 w$ H  ask roads [ set pcolor white ]  C8 ^) l5 E3 R2 H( N. c' _
    setup-intersections, q' A8 x" G0 d. }- ^. F% ]( p1 u
end
* t- v& j8 S" R& D/ L) G  q其中定义道路的句子,如下所示,是什么意思啊?% s; D- n3 ]3 a. _3 F
set roads patches with
1 [) g$ j, T" v- b& z2 K3 r" |1 g    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, X# A& C) |% W  ]5 J7 m& }
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- Y. T; Z8 K. w
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, 2026-2-1 21:20 , Processed in 0.014822 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