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: 12085|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。1 o* a4 ]! \7 f( z7 Y
netlogo自带的social science--traffic grid这一例子当中,
8 H& _, ]' F3 l" J  r# G, V" u/ ^globals
) ~; m$ j' b8 F7 l  Q/ W. P[5 T7 p) L7 x/ u6 j8 p
  grid-x-inc               ;; the amount of patches in between two roads in the x direction: d. n0 n; \6 P) k5 V; X
  grid-y-inc               ;; the amount of patches in between two roads in the y direction+ M$ ?; H; q+ p  O
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if3 i& m) H1 h, R6 M# f# C- ^% s: e
                           ;; it is to accelerate or decelerate* U2 S; X3 Q; n
  phase                    ;; keeps track of the phase) W8 G, Z, @3 H/ x" Q/ l1 }, v/ k$ G
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
$ }) M0 J% v5 _9 t  current-light            ;; the currently selected light6 x5 K$ M4 {$ t! c2 M
0 b* U. s; v2 N! G
  ;; patch agentsets
+ ]- @* e' R7 y' k1 j7 G* {  intersections ;; agentset containing the patches that are intersections
& N* T& @( J& S8 |/ J7 }- ]/ {3 t  roads         ;; agentset containing the patches that are roads
8 d1 s+ W, ^9 t% g% K1 K]+ Z' E; J7 Y: i+ E# ^5 E' x
2 E! K# `1 I. G
turtles-own
* h2 i. o+ K/ F8 ?) t[$ I. \: Q0 P' n/ }8 ~
  speed     ;; the speed of the turtle7 ]' c* N: K5 @. y1 e, T
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
+ |" c0 P6 c2 E" a  wait-time ;; the amount of time since the last time a turtle has moved
! x0 r7 s6 C! K8 n; L; p/ []
9 I. C6 f+ c% U3 y% [& _
4 J" |- q) Y; _, y# c' ~" d! J" gpatches-own
9 b0 A' |8 v1 y* M( D$ T! L- V[; q4 ?" N/ y7 K7 J3 `: b
  intersection?   ;; true if the patch is at the intersection of two roads
5 M8 [9 w: Q1 g9 P( G8 i  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
( ?9 Y  k3 B+ X# b                  ;; false for a non-intersection patches.: @7 P6 b8 u3 u3 D, @
  my-row          ;; the row of the intersection counting from the upper left corner of the( y9 G! t$ I6 x
                  ;; world.  -1 for non-intersection patches.
% z( B) j; Z( B- J# r  my-column       ;; the column of the intersection counting from the upper left corner of the
/ C" L! e" O! v" i! C  K1 P                  ;; world.  -1 for non-intersection patches.
! I( F# l3 c! Z5 \# B& Q6 a+ G  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.7 D3 m* ?  s) U( y/ b, T2 B5 `
  auto?           ;; whether or not this intersection will switch automatically.
  w/ I$ p% T/ G# i                  ;; false for non-intersection patches.; k; [- s$ J+ D
]
' U% _; {4 M7 d" ]! ]2 T; \" K1 K6 p+ l  f$ R: x. ]: @
* U6 j- q9 B3 x5 ]8 d
;;;;;;;;;;;;;;;;;;;;;;9 N) H: ]2 S- a7 [. }6 D: ~
;; Setup Procedures ;;
8 ^2 L6 x  g/ E5 U0 V2 D;;;;;;;;;;;;;;;;;;;;;;. o' h( J$ W4 }$ u% |

$ V* u" z* d) ~" h+ H( y;; Initialize the display by giving the global and patch variables initial values.5 G/ U$ ]5 Y7 p+ H2 ~: v  m+ k
;; Create num-cars of turtles if there are enough road patches for one turtle to
/ I' N6 H- Q0 z;; be created per road patch. Set up the plots.6 i$ @+ f. J/ a5 n% a% K
to setup
4 d1 v& q8 h! ^! S  ca
0 R2 i' L2 ~' p. m) m  setup-globals
9 C  y- P0 _! f( ]5 j
3 d( k, d* ^( I' x, O  W  ;; First we ask the patches to draw themselves and set up a few variables, N2 f3 z1 D% J, X0 ?
  setup-patches! e& y7 ]( c9 t
  make-current one-of intersections
) z1 T" a+ O  {0 ^( }% c  label-current
* `7 @( K1 g5 r; N- g5 M9 ~$ E6 Y: ]) g2 `5 ]
  set-default-shape turtles "car"
5 Q/ {3 W* A7 d8 Z/ v2 D$ |- |( `$ [
  if (num-cars > count roads)4 G, n( w) D: a: P+ p( w
  [  X2 \  S) I( a' S
    user-message (word "There are too many cars for the amount of "; q, f6 G# s4 q$ e% H  U, O) e
                       "road.  Either increase the amount of roads ": N8 k4 l  d2 O& q- \' u' f2 O
                       "by increasing the GRID-SIZE-X or "
& Q# R: v, D$ v+ z: d9 G; n; t* ?                       "GRID-SIZE-Y sliders, or decrease the "
% ^$ I/ G. l# B' W/ e) N+ z! a- m                       "number of cars by lowering the NUMBER slider.\n"3 ]1 E/ y% d9 y. Z) R- ^/ Z
                       "The setup has stopped.")
1 v( m! t6 e! {' n+ A: G# j8 I- L    stop' l# @2 U8 l0 k9 c
  ]
6 u/ W& V8 l8 A# l7 O
: t$ {: j( \$ j  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. I& |0 g; g5 x- H# j  crt num-cars
' ]; _0 Y& ]. y: w* j2 e, Z: K  [; ]) A# I! z6 a2 }) j% c
    setup-cars; g2 E7 ^0 Z9 n6 \% t
    set-car-color, |- M2 v" {1 H. k- W  n% c. e9 L& n
    record-data: P" V# ?+ C) q
  ]
! q8 n; j( V. |# d5 H8 W  S
2 w4 a9 y' R% h$ _  ;; give the turtles an initial speed
1 _2 U- `% _7 v3 G: S  ask turtles [ set-car-speed ]! Y- V3 @! m$ d, e& B

8 W; e$ Q- f  G1 {/ c# {  reset-ticks' \- }5 g7 D" Z: W1 `! |0 ]
end
/ }. l# D4 C( Y% }( t# d3 p3 x3 }: k* K$ s
;; Initialize the global variables to appropriate values$ E: S% P5 Q7 H8 w" h$ b2 x
to setup-globals
; A8 O, d8 W$ E$ J( O7 N3 Z# m  set current-light nobody ;; just for now, since there are no lights yet
1 k% A5 F/ R/ N) c$ J  set phase 0
: n& z! R6 {* w8 n/ B  set num-cars-stopped 0: p1 p% N4 m5 v
  set grid-x-inc world-width / grid-size-x6 _; U5 H5 I- ~* E+ {
  set grid-y-inc world-height / grid-size-y  f. x4 \3 p0 k  q2 b  k+ ]1 @5 A7 v1 |- f5 d

4 P- H6 H& c% x/ x  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 _. c& ?( _& _% x, M  R  h9 v& `
  set acceleration 0.0997 s1 G4 B5 f- u% u2 D
end" V( p- y( F. ?" W$ R& }
# [! @7 d0 r7 w/ q$ w
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* ]) o; h1 [/ q4 A9 B% a$ ~8 R) U
;; and initialize the traffic lights to one setting: C% k) j4 N) ~7 g: ]" G4 t
to setup-patches  T2 `8 S6 t' Q
  ;; initialize the patch-owned variables and color the patches to a base-color* T0 X$ d) b% q7 T: I
  ask patches' c" i& A9 V) Q! ^- A0 d$ Y
  [
0 Q# l9 c9 D6 E. l  i    set intersection? false0 O/ L/ S1 c% E+ r/ H9 N. k
    set auto? false! K0 [% G1 s7 G7 i- Y  ?
    set green-light-up? true: m2 w, }9 h6 G( j6 |1 O
    set my-row -1( J, E! j7 b0 A# r: \
    set my-column -1# E3 S+ U; _& o2 l! K) @# o
    set my-phase -1
5 j- U! c- g0 I! \+ z    set pcolor brown + 3
/ [' Q( c( v) d! h6 `  ]% e4 ?- I8 b0 p
" ?6 R: P, Q% o% ?
  ;; initialize the global variables that hold patch agentsets
5 C5 Z* Q- `) ?3 H  set roads patches with
) G* s# H! J; u' C4 }3 o9 P  z& w. M    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' @& Z5 V  z8 C4 A
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' P5 w9 f- ~6 l0 R
  set intersections roads with
' q9 U- g' c8 T; i" y* _5 U" X    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 m7 q2 b* d/ \. ^& D+ Q    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]  P  N7 i4 O: j% E

: D$ f3 @: D! G5 i  ask roads [ set pcolor white ]
1 X4 l# j  l- D* i# W    setup-intersections4 [% t" Z2 V( X3 u6 [, V' ]5 \
end
) j; ~* R8 t' Y- f! g, P+ q: ^" k其中定义道路的句子,如下所示,是什么意思啊?* E/ U' ~0 x) p- k( ?' v* t2 C
set roads patches with% c! S4 c- t* m! R& Y# y
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: @: c+ b2 H1 r8 p/ X1 P, i' Q8 L    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( ?3 [! K7 l# n* P2 h' ]6 F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, 2026-9-3 01:02 , Processed in 0.017078 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