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: 8762|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。6 P6 M6 f2 w6 L& w# ]
netlogo自带的social science--traffic grid这一例子当中,$ m# @9 A7 k6 |
globals
! t1 D8 |! _9 k[* f; I) v9 e/ `$ h0 }+ N
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
; P, a* U, q; N2 ]7 z: r  grid-y-inc               ;; the amount of patches in between two roads in the y direction9 I/ S5 @0 C# L8 n4 Y0 E! }; A0 f3 |
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if3 v. }; y. B5 \) W0 ]( x, \
                           ;; it is to accelerate or decelerate4 a+ S* G3 K$ W' @7 s
  phase                    ;; keeps track of the phase
# j0 G/ Z8 |) C& o( G6 C- z  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure6 ?5 n1 U2 }& _4 g# k) o
  current-light            ;; the currently selected light. O3 p9 F% ^% h2 s. J( V! ?

4 |7 g8 T3 l/ t3 s  \  ;; patch agentsets6 O8 `& s  K; b) C+ N# Y$ {
  intersections ;; agentset containing the patches that are intersections5 W# F7 r' o; T  W. A3 m
  roads         ;; agentset containing the patches that are roads0 S3 }% d% ?$ [7 s7 O$ t; U
]' B4 q- e6 \2 P/ h3 N4 H7 v2 c

' P4 |% z  f/ f7 Q, {turtles-own; G8 i4 Y% R9 ?6 o/ Y. H# b; d
[
2 h6 a1 s& w' J) Z1 h7 {) P4 |  speed     ;; the speed of the turtle4 W7 B3 F) p+ u' K2 P& E
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
( a4 |8 ?9 c8 K. S; K0 F0 P  wait-time ;; the amount of time since the last time a turtle has moved
! `2 P3 Q# p& n. O  x" [8 []$ {/ F! L0 @" h) O( b( [

- C0 B* q6 F( v, c( ~patches-own- l* B, R# z! Q( M2 m: Z5 B3 @: C' l
[- |. v: L  {, [- S$ i+ d( e
  intersection?   ;; true if the patch is at the intersection of two roads
, t" u. t1 Z4 ^0 u1 `$ ?  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.- c( M: ]* j5 M+ k1 f
                  ;; false for a non-intersection patches.
5 m1 n1 o7 O( z2 P! [  my-row          ;; the row of the intersection counting from the upper left corner of the
: y; p( u$ N" ^  J6 w( m" e0 m& r                  ;; world.  -1 for non-intersection patches.
- U4 _8 T" R, ]+ C& q7 k& Y  my-column       ;; the column of the intersection counting from the upper left corner of the2 }4 p" y" `/ ]5 W
                  ;; world.  -1 for non-intersection patches.
: R: i% E" T# E, e& [: P  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
! H" O, c2 g2 t0 s  auto?           ;; whether or not this intersection will switch automatically.
; v; `- d6 Y' Q& p) ^                  ;; false for non-intersection patches.
6 @8 h4 W% r! g5 Z( a& U# ]]" f5 G; m! ?1 f9 v* c: R: q! s3 E

7 F6 |( j' g% p. z" g2 Q: W( a0 r% V* @# O. h5 B* V
;;;;;;;;;;;;;;;;;;;;;;3 R8 ?% Q/ ~6 Q9 R) |
;; Setup Procedures ;;
' ^" i' M8 L. e0 y# n/ D, r;;;;;;;;;;;;;;;;;;;;;;
% x( }7 v+ z# t) `
9 Y1 c2 P9 |! B* \;; Initialize the display by giving the global and patch variables initial values.
: H5 B2 c: x+ q, X* s" Y;; Create num-cars of turtles if there are enough road patches for one turtle to+ y7 k. F! R- [9 m2 |
;; be created per road patch. Set up the plots.
3 Y# t# y# \( g8 n* r9 W0 K8 h3 Dto setup0 R5 c9 `# P; {* `7 k
  ca
; D1 x2 W( b9 Y4 x1 }# V, W  setup-globals
- n: @* {" G' U$ c2 l( n6 @- |% w# H! a
  ;; First we ask the patches to draw themselves and set up a few variables3 q7 ~9 X% i& x$ d4 E% p! A
  setup-patches
/ o) M% h3 B$ w. U- _8 Y2 C  make-current one-of intersections
6 y# I0 T( A9 e$ M+ O" b  label-current6 s4 ]$ v3 }* I9 p+ T7 O! s+ K

  [/ ^0 H9 M$ T, q3 ~# T  set-default-shape turtles "car"
) m9 K# j7 s3 e) C0 ~9 }0 L$ _! Y+ F. J/ L* Z: n, S
  if (num-cars > count roads)
# h6 F, d: j# \. ?$ K4 \  [% n/ a3 u. Z7 {# w
    user-message (word "There are too many cars for the amount of "
" Z6 B0 {, k+ G, S( y                       "road.  Either increase the amount of roads ") j4 g. E) o4 Y& U0 u7 ]
                       "by increasing the GRID-SIZE-X or "
  M( d' T9 T* ?# U% A                       "GRID-SIZE-Y sliders, or decrease the "
/ [' Q& p$ E0 ?" C0 p4 Q                       "number of cars by lowering the NUMBER slider.\n"
0 x$ v7 ~" ~$ K0 ~) ]                       "The setup has stopped.")* Z: V9 }$ w% ]  \; z9 ?, z& Q
    stop( ^5 ?* u: C5 \. ]8 E2 M& u& I
  ]4 J! e0 }/ z& |$ h3 [8 G4 z
$ h, S5 ?8 z- P+ K7 k
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ U, X, B$ \. G% h5 Z: t  crt num-cars2 S# t' p, r+ l  B$ k
  [
4 E- \4 Q: g% k6 G/ N9 B    setup-cars
3 r6 h/ q# ^" [' J! m5 X    set-car-color
  p9 u8 Q" r8 f/ ?; D7 Z    record-data
3 ^  b* w2 P  n( }/ s  ]
& W6 _! j0 e0 c( K2 D2 O3 n- h! q+ k6 v/ E% O# r6 ?' S$ H4 D: S# g6 M
  ;; give the turtles an initial speed! ]8 q9 D6 U6 s. `. V
  ask turtles [ set-car-speed ]+ \2 n- n2 e6 ]! l" w2 W

/ P5 a, Q) e% m. J2 G  reset-ticks6 @8 `$ a; b- Z7 x# T& O$ B
end) R- Y9 R7 ^( O- O4 q' E, A

2 C& t  @, s/ y;; Initialize the global variables to appropriate values
/ E1 X, @! _' O5 j7 Gto setup-globals
3 h# S9 m4 _* ]1 v: Y  set current-light nobody ;; just for now, since there are no lights yet
' N$ N3 a- K5 d  e! g+ x  set phase 0
+ m5 @& d! @7 [6 j& a  set num-cars-stopped 0
% a( Z" _. M1 t- }  set grid-x-inc world-width / grid-size-x4 m! S4 H. c0 `3 V
  set grid-y-inc world-height / grid-size-y
/ C+ @6 h2 ~* O) q5 g* S
0 v% a$ ]. V- Z  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 R! W# @6 Q. T; f
  set acceleration 0.099! S8 W. X$ ^  ]$ V! E4 d
end
7 U7 i7 ~* V9 n2 H2 G$ v6 N8 M" T3 i% B' B5 `
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ S2 J6 [2 K5 x7 Z5 m: E' |;; and initialize the traffic lights to one setting: I" a$ |- t: D/ i: P6 \) A
to setup-patches
, O* L0 C2 d9 p6 X  E' q3 D  ;; initialize the patch-owned variables and color the patches to a base-color" E* D% Z# O: Z
  ask patches& \! _7 f# |. u5 `6 L( v- [( H3 l
  [% w- G# }8 Z# |- a! x- H: z' e& g
    set intersection? false! Z2 c2 I# H' E  E$ {
    set auto? false
7 B5 `3 [: x# `, w" k- U    set green-light-up? true0 E- y3 _% B5 a* t) U7 b) r
    set my-row -1
0 z# Z0 l5 p% e& G% I: g+ J" r    set my-column -1- l/ u: j* f  }6 c! B# o7 ~6 z
    set my-phase -12 ]+ ~, U$ K0 I. e2 f
    set pcolor brown + 3
) `3 v8 S6 P, N& ]  ]" a3 r; ^: P3 ?. K

8 a; S' `2 \/ I, [; W( o4 ]' u2 R3 V  ;; initialize the global variables that hold patch agentsets* h. o9 Y) C/ Q$ A0 d
  set roads patches with
8 Z3 ]1 s* N) H0 V1 k* D  r    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% V% o' g2 g" [/ {% o
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; d: o, X8 o. }' p% f6 r$ j- A. S  set intersections roads with" X8 b  O0 J/ {# h/ _+ G8 ^& |
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 G9 t/ q% G" \/ o    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 v; c/ n1 [6 \4 Q* W' X; k

, r/ o8 N. z- Y* R, t3 y& C  ask roads [ set pcolor white ]# y+ q3 V* l8 z3 G$ Q+ G5 \
    setup-intersections2 j. R  {$ F" k/ L8 h5 o
end7 G8 R' A" `0 `# O
其中定义道路的句子,如下所示,是什么意思啊?6 ^; C$ t5 `+ P) I
set roads patches with! t5 t3 c  _2 J! `
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( a( _* E5 \7 C. W4 ~# q% c    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 C# f1 i2 l5 q, w0 [2 `$ 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, 2026-3-8 10:46 , Processed in 0.014977 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