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: 8129|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。* n1 p: X" t: D" a
netlogo自带的social science--traffic grid这一例子当中,
. A9 U% L' A) {- m) uglobals' ], l5 m* {! E) [8 }* M2 N
[. ~  f5 G% J# \3 T2 I9 [
  grid-x-inc               ;; the amount of patches in between two roads in the x direction: Y1 e, d5 R( x: U4 q/ r
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
5 ~, f! o9 N: ?9 r. P  acceleration             ;; the constant that controls how much a car speeds up or slows down by if8 w- ]& B' G' j& ?2 s5 C0 {
                           ;; it is to accelerate or decelerate( e3 c  z9 I- J- F" u
  phase                    ;; keeps track of the phase
0 }4 L" G" j# k! w  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
0 ?9 G$ [- u  l# k, J  current-light            ;; the currently selected light
% M$ a7 ?, m" r( N! R6 L2 N6 V2 Z$ Y8 p
  ;; patch agentsets4 U1 ?3 C# @0 ^- f* B! C9 ]: u
  intersections ;; agentset containing the patches that are intersections% N6 s7 Z7 x7 v2 D
  roads         ;; agentset containing the patches that are roads$ V' u+ \: E/ B9 z6 l, }  W" \+ X
]
' Z4 q' y, r, z3 A
/ [( B8 z% t0 c* I4 `. nturtles-own/ p# F( L9 J; u/ K3 j" F7 |
[6 n+ ]6 W2 F: t( [6 V  m% B
  speed     ;; the speed of the turtle, S: @8 z2 e3 H9 v( @( R% S
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
6 ]4 A6 c) t' \  wait-time ;; the amount of time since the last time a turtle has moved
+ H% h9 x8 l5 A' t+ f3 Q; x]* ?9 r# G# F& ^" X3 R& G

6 y" ?+ X; O2 e! e0 n5 H3 N( f/ e; \patches-own
1 u3 q8 P$ W" f- B5 j: t[( B8 V7 s* G, f  F' \# Q) k1 e1 c
  intersection?   ;; true if the patch is at the intersection of two roads1 n$ Y' _4 u8 P2 h/ Q2 D* D0 X
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
" y. f3 e' K" l7 K, _                  ;; false for a non-intersection patches.  J; i# k5 X. ~# [- j
  my-row          ;; the row of the intersection counting from the upper left corner of the
8 s* d* u  W7 X; z                  ;; world.  -1 for non-intersection patches.& t7 T, M: V4 b' h' x' B. V- W9 d% ]4 |
  my-column       ;; the column of the intersection counting from the upper left corner of the
# R+ _! u/ h! n                  ;; world.  -1 for non-intersection patches.- [/ c' [' J# e% a' M/ z
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.' t- S3 u* I/ S+ Q
  auto?           ;; whether or not this intersection will switch automatically.
/ {5 x7 b; c- ]: L7 R4 v% m) E/ |                  ;; false for non-intersection patches.4 Y2 M& F) m2 N6 L
]
/ g1 w& K: ]3 H4 ]$ Q/ m7 V, z+ g2 B: M& ]1 [; _1 @. S; U

# @5 V( K3 J* N  };;;;;;;;;;;;;;;;;;;;;;0 `. W2 b' D. B7 ?; l# a
;; Setup Procedures ;;( h! _  s- W6 O8 K  T, E' T) W# }
;;;;;;;;;;;;;;;;;;;;;;
, V; c+ |# `) Z
( ~7 ]* V% |& l2 S;; Initialize the display by giving the global and patch variables initial values.! a$ F% _0 o6 ~! Y4 c- w
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 g. ~% B  N- Q3 Z;; be created per road patch. Set up the plots.
! @$ g) k6 P$ uto setup
! |" p- h$ f0 z" J& P  ca
, [& ?2 P/ Y+ J7 A9 y0 u7 O) {  setup-globals
. ~' F, F. c2 x5 c: }* E( f
4 f( T( m  G% S8 i' Z; I  ;; First we ask the patches to draw themselves and set up a few variables( P4 ~( x0 I$ e7 Z5 x
  setup-patches
) W3 j, N: ^+ G: E& m" p$ B- k  make-current one-of intersections
/ z* Y5 p, v& y  label-current
2 |: v# H; Y) j/ V; f+ x. z! P% Z7 e: p: y
  set-default-shape turtles "car"; @3 C; Q. T; p- Z% @5 A
+ |' e1 @2 C' y* |" s: m3 q/ j
  if (num-cars > count roads)) N9 N. P* x  I- l5 d
  [4 t2 q/ j, \& Z( u- n! l
    user-message (word "There are too many cars for the amount of "
8 \) `/ j& V0 m) m6 u9 l* A% h                       "road.  Either increase the amount of roads "
7 F; i. J# t8 y* A5 l# ]                       "by increasing the GRID-SIZE-X or "
3 w8 [: c# S$ {" N3 G) ~  D3 K* a                       "GRID-SIZE-Y sliders, or decrease the "
: I" v# X3 K" U4 ]  Z  S                       "number of cars by lowering the NUMBER slider.\n"
  o; I) b; ]$ B+ ]                       "The setup has stopped.")
: y- S6 Z  d3 K  K+ P  B) o" I8 \8 m# F( Z    stop
  R& r3 L3 ^: E2 V/ W7 F4 Y: i, z7 M6 A; Y  ]4 _/ R4 k6 [" s! L6 Z/ i5 S

3 x1 |' L$ R' X- l  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ S4 s# ?% r# h  x. \. B  crt num-cars# g' w/ ?1 F9 S/ w9 g7 {  B1 b
  [) K- e& l, l9 |6 l
    setup-cars+ K/ M9 y5 r: \1 [+ p* E& C
    set-car-color2 V( A. Z! z; ]) ]
    record-data2 I) J& R2 c$ Y% {# \
  ]
+ p2 n) v* w0 Q% \- Q2 P
# |+ w) G9 `( B$ h4 l0 h3 c  ;; give the turtles an initial speed" i! ~( [9 O5 Y  s
  ask turtles [ set-car-speed ]
) s# F/ j0 J6 G- w! d1 F& R. _
6 P4 f$ _, _/ r  reset-ticks- U$ @) s4 M+ E7 Y
end
+ G0 w; ^+ u" w9 z. v6 J+ v: q: q8 L. |
;; Initialize the global variables to appropriate values
& v5 o: G7 l$ p+ I# kto setup-globals3 M9 _2 R( E# Q4 X
  set current-light nobody ;; just for now, since there are no lights yet$ M3 Q! s1 q7 p! e
  set phase 0
( d( q% y8 u9 K0 |% k( I" r  set num-cars-stopped 0
) W' x" a! {' U% ~* d9 ?' z  set grid-x-inc world-width / grid-size-x
4 h2 U9 ^) S0 b  set grid-y-inc world-height / grid-size-y
; R7 Y0 ]) t3 @. J2 Q- U0 T" y  x# T' y0 O! D
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary) V2 E* r* n9 U% k5 g" U9 C
  set acceleration 0.0997 _  D0 Z/ E, O3 Q
end5 Z5 \" k% M4 ^/ p# Z* R7 i
- U1 ^- z. M. F3 v! }: K
;; Make the patches have appropriate colors, set up the roads and intersections agentsets," D2 ^) J! K- E2 N- i
;; and initialize the traffic lights to one setting
7 G+ M! g2 X. P0 S' @2 l) Lto setup-patches
# v4 [2 `3 _2 |% C. G. S0 ]  ;; initialize the patch-owned variables and color the patches to a base-color  S' V8 W% f, m' |1 Z% M9 z
  ask patches! I- h& r$ h& B. y
  [# {3 o& B0 d4 x( I3 h" I
    set intersection? false
8 O2 x: S' q1 D% f+ u1 J) z) W6 w    set auto? false
* s# D3 B0 |0 t8 E; I8 F    set green-light-up? true+ D: L+ j5 @- V* G$ ?
    set my-row -1- c7 o+ G: {: V
    set my-column -1, y- N$ N" ~; C, g! r
    set my-phase -1
/ m5 G8 Q4 o4 X% ]/ @& i% u    set pcolor brown + 3
9 I3 i# |0 e6 D" z% }0 F3 b2 L* \  ]
& {  j2 j# c5 E) w" d6 P5 P  B6 Q  V, n( ^
  ;; initialize the global variables that hold patch agentsets. o$ }- v" }; h5 c% D  ?. N; T
  set roads patches with
- R6 S4 U. r% }& D1 w    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 C+ D# S; z7 \4 `- B  |
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 t9 k  q2 U* h$ \* j' ]
  set intersections roads with5 K- q) X; l$ ~9 U: ~2 j5 `- x
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ Z# J+ V' s0 _( N7 g# G    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 U3 ~2 }6 h  o( P! u  R6 l

7 G7 b7 X3 c5 j1 e( ~7 \7 r  ask roads [ set pcolor white ]
+ E1 U) K$ ~) H. W, M    setup-intersections
. B1 T3 I6 R- Z! F; g8 g1 f6 lend: x. a7 U0 y0 A; `
其中定义道路的句子,如下所示,是什么意思啊?2 u% L1 c8 V7 h4 S" q0 T+ f
set roads patches with
6 D3 g) R1 O( G# D    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 z7 b% O9 M; z3 {! \. m  h
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) U2 y' C+ g9 q  E$ T6 x  Z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, 2026-2-2 02:38 , Processed in 0.015047 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