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: 11769|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。& ^* i. @: Q, Z6 R' q7 z5 _" a
netlogo自带的social science--traffic grid这一例子当中,! o1 M4 g& T6 b8 _" v3 Z
globals
$ ^% u. ]" ]+ G9 h) ]3 ^[
. b! [+ @- ?& b6 M  w$ N+ Z  grid-x-inc               ;; the amount of patches in between two roads in the x direction
# y% ?: n1 _6 \* W* w  grid-y-inc               ;; the amount of patches in between two roads in the y direction1 P" G6 z0 ^$ P/ P" Y2 X
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if! O/ v. j8 g" S. L4 s4 E
                           ;; it is to accelerate or decelerate
2 c  j; @# |4 a& W8 U  phase                    ;; keeps track of the phase
! w, F/ p5 S* p: ^" v, p, r  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
9 B. \- M8 o* G; e3 t# k8 D. ]  current-light            ;; the currently selected light
/ V. k9 l. u* r! @
5 [# k8 e* b! e, l- |" Z  ;; patch agentsets
* @. g# ]6 {' Z; Q' {5 B+ ^) H5 ^  intersections ;; agentset containing the patches that are intersections' n2 Z( w" F0 Y- |
  roads         ;; agentset containing the patches that are roads/ o0 G* l4 _+ k, K
]2 C9 P$ K! Q8 M( r. W$ M4 s+ |9 h, M

" j4 f* W# G; I8 ^3 b  z& s. Xturtles-own. I* }% S9 R+ Z
[
2 l* O4 Q9 ]' m4 s: e5 Z: Q; ?  speed     ;; the speed of the turtle
2 }6 N5 `4 z7 j, z  up-car?   ;; true if the turtle moves downwards and false if it moves to the right# ?; U& g3 V( v  w
  wait-time ;; the amount of time since the last time a turtle has moved4 D2 d6 y6 ~" L3 u
]! |2 O. H2 V' n5 r9 x! g# `% M

; f1 R3 d; O- q- j8 Tpatches-own9 D& S0 @0 T; k& S& G
[
; Q' z( B! A9 C  K  intersection?   ;; true if the patch is at the intersection of two roads
$ j  K% b6 p! N3 `( w  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.+ }+ Q& \: s' D, Y
                  ;; false for a non-intersection patches.
& ~; z3 R& r; Q0 L$ H. h7 D7 |  ]  my-row          ;; the row of the intersection counting from the upper left corner of the
1 a% Y( a8 X3 q                  ;; world.  -1 for non-intersection patches.* M3 `6 V) Q& F6 {
  my-column       ;; the column of the intersection counting from the upper left corner of the, G8 V- Z9 P( C
                  ;; world.  -1 for non-intersection patches.- }7 p& b3 c& x% f+ h
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
+ r6 \' [4 W* b/ Y3 c# |  auto?           ;; whether or not this intersection will switch automatically.# l6 p- x& A+ p4 ~
                  ;; false for non-intersection patches.
) Z3 p. H0 h* N" G+ p]0 e8 t; F+ R2 E
! B2 P0 ]! K9 o5 A

  y* y+ F; i5 L;;;;;;;;;;;;;;;;;;;;;;' v2 V" |; `6 U' @
;; Setup Procedures ;;0 d8 G( N6 _# |" L5 J
;;;;;;;;;;;;;;;;;;;;;;
3 a. C: Z- A+ C, L7 ^3 C" k
) G) D$ [" S) o$ i;; Initialize the display by giving the global and patch variables initial values.7 N1 u! N" W) _, O
;; Create num-cars of turtles if there are enough road patches for one turtle to& M2 `" I+ s* h
;; be created per road patch. Set up the plots.! [" `& P' K) _1 f) e* i% e, \6 X% w
to setup2 A3 |. X! }7 b/ U* Y# G2 R2 @4 a
  ca
( ^; }  X! _/ P0 |  setup-globals0 t* d, S) g) n) R4 Q, x
; `& m5 y- ]) g0 z  o
  ;; First we ask the patches to draw themselves and set up a few variables9 ]0 p; m) f% M, |2 F4 e
  setup-patches
+ y2 S  t, w$ i( U  make-current one-of intersections
' t8 v% k& z6 a, v9 d  label-current
% q5 K# g7 L' e7 t$ I8 N- Y4 |
5 z& q: r* D' J  set-default-shape turtles "car"% J/ ?! W" {7 o6 g, |
* W) w# ~# P' W  G# f0 R8 W4 c1 @
  if (num-cars > count roads)
9 d: N, B/ s0 `+ P  [5 c7 Z: U0 t, L$ n6 s
    user-message (word "There are too many cars for the amount of "7 U3 w! A0 p! I7 ^; h+ y, b6 Z
                       "road.  Either increase the amount of roads "
( Q6 P2 {# W5 i5 N                       "by increasing the GRID-SIZE-X or "
2 N/ D/ [5 H6 p( }                       "GRID-SIZE-Y sliders, or decrease the "
# A- {& X7 b& Q                       "number of cars by lowering the NUMBER slider.\n"# ]" v. B7 Q. z( I' y9 j! g
                       "The setup has stopped.")$ r0 A4 t$ K* z$ i7 G3 }+ o4 h3 v3 }; W
    stop+ l4 L8 w# x0 o0 d
  ]
, l( ~' m$ T/ w6 f" _: z1 ?8 {7 a# s; Y+ Q; I( I
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 u' V9 Y$ }* R
  crt num-cars
3 c0 S0 e9 v( \3 I  [/ N% `6 h* c( e
    setup-cars
; @3 t, F9 L) o. k    set-car-color& y  {8 F# ^: E& V
    record-data6 j9 Z" b  C9 W1 {
  ]
: u- ^0 ]& N, x) Y% G% Z3 \5 [6 G( T9 e, u. d% k
  ;; give the turtles an initial speed
3 }3 s+ R& X- L- ]  ask turtles [ set-car-speed ]* b8 V+ H- M6 i0 n1 }) X3 \
& E' Y7 S* A0 E' R9 L
  reset-ticks
0 Z! A5 F! \. v9 x# f# q8 O: i( iend+ B* d8 c- P  F7 ~

, h0 M) n* I7 D5 ?# @' _, S6 D;; Initialize the global variables to appropriate values0 v6 v. A8 x! v+ z2 V5 T
to setup-globals
: a7 K3 _% ?* m# D  set current-light nobody ;; just for now, since there are no lights yet
7 d0 o) s$ Q' s5 U$ C) ~& A  set phase 0
# ?4 Y* P8 O4 D  set num-cars-stopped 0
2 I  C4 t0 S# {" B- X4 O  set grid-x-inc world-width / grid-size-x2 _# E  G+ M6 L5 I  |+ i, F
  set grid-y-inc world-height / grid-size-y
4 j4 d* m" \. ?  X6 K" L
' o' A. B9 V- U9 [  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary" x3 p+ P/ ?) q
  set acceleration 0.0998 \) z' h- T+ t8 Y% x$ [
end
. e: H( ?9 K# p# Y# `- n+ Q5 G
  H5 {' y6 X4 J* H# @6 e6 L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% c6 e5 V4 X+ p% ?5 P% F;; and initialize the traffic lights to one setting' o. |- Q" R! H6 W5 H
to setup-patches
1 i* m- A; @9 B' ~  ;; initialize the patch-owned variables and color the patches to a base-color1 c5 y9 u: B# V, @" v4 q
  ask patches
5 ]1 G& E+ l4 k: l3 i  [
1 d: k, _( J0 j2 s8 A    set intersection? false& ~' I9 {2 c$ l+ U% t* w1 `8 Q
    set auto? false
, m, f4 ?  ]! {% L4 q/ I% b. l    set green-light-up? true
# P4 Z8 ?0 ~+ q4 i    set my-row -1+ }% A2 z" Y/ b
    set my-column -10 }: n1 d6 j9 _' Z0 F9 L0 o
    set my-phase -1: r3 R( Z( m- h
    set pcolor brown + 3
# q) X, a/ ~. E" k7 q: ?0 N# n  c  ]% K. S9 B7 a$ f

  K* n2 m2 M& Q  ;; initialize the global variables that hold patch agentsets
! v1 t: f3 F- ?- H8 U. ]' _; x  set roads patches with
* k# R" n& d8 F% h" b6 d: G: q: g    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 x4 @( k, G" H# D% C    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- r$ Y0 T- k0 Y, |3 V! R# L7 X( r) r  set intersections roads with4 b5 u5 `; H/ C) u, ^7 A
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 E! d1 {( q; i    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 @: E2 u8 Q4 U+ G( a2 `
$ W5 P# j/ Q. {5 w  ask roads [ set pcolor white ]$ D0 D+ Y$ @- n% k/ O
    setup-intersections. [* p6 r1 t% g6 X1 e. g& A) J
end, i. ?+ n# z; j; ?( S$ }% P
其中定义道路的句子,如下所示,是什么意思啊?6 E" z9 x: T# R: B
set roads patches with- {3 y5 l- ^7 C) ~# v
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or  f" |; ~, y3 H% c6 A- R' ]6 x
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* f' z$ G9 Q' s! }  b* V; E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, 2026-8-15 15:06 , Processed in 0.014385 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