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: 10556|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。' M3 r7 n2 x7 E" C3 i% L) R2 o
netlogo自带的social science--traffic grid这一例子当中,
3 {1 [! b2 d5 \1 d) c' w. tglobals( a9 h% g, ]. l3 Y$ i+ i2 y/ ]
[
: g+ t7 ^. R& ]1 g: G" ?  grid-x-inc               ;; the amount of patches in between two roads in the x direction# j& S% M9 F+ n% l" \- Q  p$ L
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
7 f: i& c) o& B  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
/ J1 |: M4 d2 p7 ]                           ;; it is to accelerate or decelerate
6 p1 q# M2 i% R; V1 w" t  phase                    ;; keeps track of the phase
. E" O/ x1 r% r: E  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
3 i, Z' k  o. z6 c: c  current-light            ;; the currently selected light
; u5 n4 O  T) P( _0 M/ F* ^( r* Y# u& ?& f9 c7 l
  ;; patch agentsets! H, G, q+ l! o) y+ p: G
  intersections ;; agentset containing the patches that are intersections$ S1 J8 ?9 ~- A' f
  roads         ;; agentset containing the patches that are roads1 _4 p* M1 l1 ]; L" h. y! A
]
- z+ M! M% B  ^1 c$ ]
* ?0 _6 _& Q( p! r) n- ~" T8 ?turtles-own
# @0 K" k# D3 i0 H$ u[% l$ d( {5 ]3 B5 D
  speed     ;; the speed of the turtle2 S$ w4 m' }( j3 M9 |  W0 }
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right# b5 r0 p+ E6 x# V
  wait-time ;; the amount of time since the last time a turtle has moved$ O. n4 D: m8 t- K8 M
]
8 K. k3 k& G9 J4 S! B  r7 f" r9 Z) D* G9 ]- O# _/ h
patches-own
$ t3 a: E7 P+ {" F[
$ J( t/ ?6 p! J  intersection?   ;; true if the patch is at the intersection of two roads
" ?) p/ e$ B) m; Q  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
9 j* I' ^3 X! d2 j0 D. D                  ;; false for a non-intersection patches.+ A- h/ `0 F+ W  w$ k! N
  my-row          ;; the row of the intersection counting from the upper left corner of the+ N1 k! A+ n; X; N# V+ z
                  ;; world.  -1 for non-intersection patches.
) O$ q0 W' ~# b, ?( m! |0 |1 @  my-column       ;; the column of the intersection counting from the upper left corner of the
4 c3 ^7 y; Q4 z  w  Y) E# J4 P- H0 o                  ;; world.  -1 for non-intersection patches.
' B6 E* c% E$ b  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
6 p9 b) c+ D5 b" d0 `  auto?           ;; whether or not this intersection will switch automatically.
( M6 e& U2 \( v$ m( d8 J& y" R$ i                  ;; false for non-intersection patches.
' A6 L( m+ F. I& V# D]
& a& e& \( e4 M& O# o5 q- {2 v! S, _+ O6 {5 s
" u: m( b; g- z3 c
;;;;;;;;;;;;;;;;;;;;;;
- O; \% V' k- ^" H* e;; Setup Procedures ;;3 y7 E9 s$ W% ^# N
;;;;;;;;;;;;;;;;;;;;;;
; l$ {1 _+ f- w$ b4 v  H) B8 Q& i% _1 d! P* p
;; Initialize the display by giving the global and patch variables initial values.
% T0 W6 Y: i: d;; Create num-cars of turtles if there are enough road patches for one turtle to
1 {8 w& @+ t3 K$ ];; be created per road patch. Set up the plots.
- S3 E1 }* j: H0 g! i# bto setup
- p, F6 q- e3 B* _; u" C& A" e  ca
% C1 T" F  k3 d# t+ [  setup-globals
% G7 S6 G9 H8 D+ Y, c* b* d' Z
7 R" Y$ a' U' y# R  ;; First we ask the patches to draw themselves and set up a few variables1 _9 V. o1 F* W  A
  setup-patches) c. t8 x3 i+ X
  make-current one-of intersections- D; x* i/ a% K% X
  label-current
( S* r& l* ^1 F5 x4 j4 j! q1 V$ |) f6 G* I( P' K, A' Y
  set-default-shape turtles "car"
% y$ P+ A' y6 D# O  L3 E
/ W3 _, P2 D3 j' `3 f* G& {  if (num-cars > count roads)# _) `4 b+ K8 u; |+ e
  [
, d. v1 z# B5 v1 x    user-message (word "There are too many cars for the amount of "
$ l  Q$ w0 u/ Z                       "road.  Either increase the amount of roads "+ a1 V: f2 S* o5 w3 L; r
                       "by increasing the GRID-SIZE-X or "; g- N4 c9 t6 ]9 n" p1 r3 H
                       "GRID-SIZE-Y sliders, or decrease the "
& ^$ Z* _9 m9 O5 o/ E                       "number of cars by lowering the NUMBER slider.\n"& A- I* }+ L" v- ~" P( P
                       "The setup has stopped.")
; D9 G8 h) H$ I, W* x) ~+ y    stop- R4 S+ w" Y) v
  ]
, s' X& C  s5 o) k# B' j) J4 l$ t1 `: z! z) T& O
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
! ~% W, g: K3 u- I3 T  crt num-cars
4 O! t, s$ B' O  [
2 ~5 z" b0 y2 U. s8 ^    setup-cars
! G: `6 @; y# C    set-car-color! i' l5 ]4 F$ A! X' C( x
    record-data% g% B8 R/ I, k
  ]; x8 L8 A+ J+ {: ?% h$ _  B, f
* T% ~8 c* q' o2 `" ]
  ;; give the turtles an initial speed
8 D0 r& n- B" R5 `" S! Z9 a  ask turtles [ set-car-speed ]& c% y" X% V" v* m: F/ b# Y- O4 T: ^

8 ?" O! U3 T" j2 B4 ]  q  reset-ticks- ]  Z. L+ T; [3 @# q5 Y3 g
end
  r! k4 \* D3 w; |- S3 ~2 @  ^1 J7 N7 Q, f# [' F1 K. k
;; Initialize the global variables to appropriate values
9 A+ q4 a7 T- Rto setup-globals- F8 }  I. h- b* }* I) y
  set current-light nobody ;; just for now, since there are no lights yet% @; ?7 I' t5 {- x2 H6 t
  set phase 0
8 p) t/ ]; o/ a* Y  set num-cars-stopped 0; x/ G5 a1 s' j- W: A/ t
  set grid-x-inc world-width / grid-size-x1 b) N3 Q% h0 Y+ F
  set grid-y-inc world-height / grid-size-y
+ I; v# a" C8 j) t3 ^8 `. d
; G* _1 t0 e, ?  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 g. K; ]/ k" @/ {: _1 C' J
  set acceleration 0.099# r* y% Y5 [/ g4 k( Z" V. ^- ]
end
" j; K) f: l$ E$ r% e% s
" G5 C- V& r3 H; }, L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,2 c8 \9 k7 j  ~# j$ u* ~* R( Y9 w
;; and initialize the traffic lights to one setting
' E2 }- \4 D, T- Jto setup-patches/ Z' Y+ C/ Q( V5 L- G+ u$ E$ j
  ;; initialize the patch-owned variables and color the patches to a base-color0 A( y" ?+ C0 k- ^
  ask patches. l& ]' I! Q1 v/ ^, R" F" b2 u
  [
  Z0 U' v8 s0 M5 v  r/ H- g    set intersection? false
* F8 H; Y4 W, h  i    set auto? false
. p6 r$ K7 r& H4 R6 T! F- B+ X    set green-light-up? true3 k$ D: [7 I6 ?( b) o" @' N
    set my-row -1
) v3 n+ i, K( B! W. w    set my-column -1
+ s/ |2 ^& D9 d5 N* R5 S    set my-phase -1& K) O. d9 w* `: A/ [  i
    set pcolor brown + 3
6 i5 s/ r% a5 ~3 u  ]
2 i* Y" ]; Z8 L
3 S$ X1 N2 p2 S' |  ;; initialize the global variables that hold patch agentsets- _1 e+ {- y  X: K' W# p, F* L
  set roads patches with
9 H, H2 g" S' \# ~# g5 t( g    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# j& I( X0 v5 N5 a7 h9 F( F. B8 ?9 p# z  F    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; }5 J* e6 e* y( J5 u8 K) w  set intersections roads with( Y2 ]: t+ ~; j" S: u
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 L8 S) E* C( H. h    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 U+ V- [6 v) A0 d0 J- G6 H; u  k7 ?# B4 D
  ask roads [ set pcolor white ]' R) w2 D( z% j+ c
    setup-intersections6 Z1 z+ }0 H* Q" j1 H
end
# s, s- j  ]* D$ @6 G- }其中定义道路的句子,如下所示,是什么意思啊?8 |% s3 Q' ?/ R  x. [* ]1 v
set roads patches with, o' `) j/ M; J
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 U. V4 X0 m9 W2 k, u    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 g! g+ [7 {* R
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, 2026-6-13 14:29 , Processed in 0.019220 second(s), 15 queries .

Powered by Discuz! X3.4 Licensed

© 2001-2017 Comsenz Inc.

快速回复 返回顶部 返回列表