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: 9281|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。0 N3 g* b. v# E/ _
netlogo自带的social science--traffic grid这一例子当中,! C" q- W2 e7 G; ^
globals
' N. `; T0 \) p1 O[
% m$ q0 Z: c& D! F1 F# e$ f) j  grid-x-inc               ;; the amount of patches in between two roads in the x direction# z# W1 L+ X# k6 G* M
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
8 {3 M4 j! N' f  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
, ^$ x4 S8 k! i* y; d1 p- T                           ;; it is to accelerate or decelerate
1 F1 ]3 ^! @3 y' e: v3 U+ R6 }  phase                    ;; keeps track of the phase
) k2 C- P4 m* b6 Z8 Y! L$ U: v  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
% }) x! j; C6 E0 k9 V$ Z$ p% r. b/ q  current-light            ;; the currently selected light: N7 v. l) N) B1 i4 }* y5 ^1 r

# J# s2 o8 m) w7 u' x  ;; patch agentsets
5 E: m5 b* h% Q% N! y: D) l+ o  intersections ;; agentset containing the patches that are intersections
/ s/ Y1 C6 L' g0 i- I& E) n  roads         ;; agentset containing the patches that are roads
# I3 p) m* F2 _/ I]
3 y! q# z4 @9 m3 |8 U- J. _6 W% a, ^
turtles-own- u$ s# e4 T% V/ S/ F
[' }8 [( s' }- O( k- ^) O) J5 x
  speed     ;; the speed of the turtle- T  A: h" s4 Q
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right  B4 ?6 J: i3 e+ t- }. \+ S
  wait-time ;; the amount of time since the last time a turtle has moved
- A  @% s. S0 X. G1 M  I9 q: H]( `% O# b+ ^  L- G3 p; [! _

+ I# _! l6 E+ G0 d# m" c0 ~8 A. ipatches-own7 E# i( D9 E+ X8 E. |# a8 P, j. W
[, W. f& h" u) X7 Q5 Q4 t
  intersection?   ;; true if the patch is at the intersection of two roads
" _) g7 Y+ o6 S" F+ }  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.! B: P+ A1 g; ~# I- B' b3 X
                  ;; false for a non-intersection patches.8 W; U% h2 ~9 m! b# R+ t
  my-row          ;; the row of the intersection counting from the upper left corner of the
( @9 m: i- W& F. `  S( M2 i5 M                  ;; world.  -1 for non-intersection patches.& {" L# ^; T, E9 u, U- m
  my-column       ;; the column of the intersection counting from the upper left corner of the
7 l* Y8 v% ^5 F4 }: {/ e                  ;; world.  -1 for non-intersection patches.- m8 q  j) B3 U, ]' u
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.( d$ B0 c3 [% j" T% e: l
  auto?           ;; whether or not this intersection will switch automatically.
" b. R# @6 w3 P  s" V                  ;; false for non-intersection patches.* u/ I* E; Z" y2 B
]5 ], }$ P7 N! Q! J
6 J# v. m( E2 w# m! a( ]
6 `3 |/ {  E( p6 b1 e% P
;;;;;;;;;;;;;;;;;;;;;;- o4 v" {5 i  b# S( z( o/ A9 _
;; Setup Procedures ;;
  ]! h1 x' f7 e! ^: l;;;;;;;;;;;;;;;;;;;;;;
$ I* V/ R( D/ Z; o0 v  P5 d) t( q1 N/ V/ m0 D. [
;; Initialize the display by giving the global and patch variables initial values.
; S& H& \& V" S. B" a+ {;; Create num-cars of turtles if there are enough road patches for one turtle to# I& u1 O& R7 {! D" ~6 i7 U
;; be created per road patch. Set up the plots.
0 P: b8 N% ~' {% w6 R4 cto setup, Q# W/ d: |8 R7 I/ N8 h# Y
  ca  X$ [2 h8 k- l+ B4 q
  setup-globals
1 h# f! W, ]: |3 g+ d7 _! s  k& e
0 H- Q. I. t# n0 x+ e) F, U  ;; First we ask the patches to draw themselves and set up a few variables
. L& P4 Y( P3 y) D) ~  setup-patches3 ~# L6 F9 _: @- ~6 X3 l0 Z
  make-current one-of intersections
$ ]1 Q7 U3 A/ i6 n" b6 s  label-current
' I8 N, I4 g, u. S: W! o
6 F1 B" O1 ?, F  set-default-shape turtles "car"
' U3 h1 s" [7 N$ d" W
, x, S. ^( }& n  f* R" R: u6 ~2 S% j  if (num-cars > count roads)7 @' k1 c) o. _4 [: {# d# O* r
  [( r' R: i$ i2 {: z5 V, q
    user-message (word "There are too many cars for the amount of "& P2 S% k  w" g: H
                       "road.  Either increase the amount of roads "; C* R9 ?# L3 p0 _2 S( J
                       "by increasing the GRID-SIZE-X or "
6 s4 u8 b) c# d5 D. H. _/ P, ^                       "GRID-SIZE-Y sliders, or decrease the "
: ?9 [) j" Z* A' r1 d2 Q6 J; _                       "number of cars by lowering the NUMBER slider.\n"
$ F& L+ o* q; A0 Z$ u                       "The setup has stopped.")$ z" \% N1 h& w9 W, N7 U) l. m
    stop3 ~# @, I0 f" e0 x
  ]
! T# S- X0 @' Y8 n
( P9 E# _$ n' C& ~2 d: A. ?: H" P  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( L1 p4 \  q! h& y; X4 B( G  crt num-cars5 A9 \8 Q- A/ ^
  [  _& |; M5 b% g3 _
    setup-cars& d5 }( j' ?* [" X
    set-car-color$ i( j8 L* Y4 d5 Y
    record-data' V& {1 [% ]* ?" I. |
  ]
1 l5 y3 N+ `7 _  W3 G" l7 w: b' P
+ q# [! n5 v9 y2 U# k2 x! y  ;; give the turtles an initial speed
5 s6 O+ J. g/ M4 s  ask turtles [ set-car-speed ]
. u0 P, K! G* j  y* P9 M0 q1 }6 F
  reset-ticks1 G. w9 n7 d4 Y  N: g7 k" t
end% @7 @7 c; r; {

' N" A) i6 R3 s% P* I. x( f;; Initialize the global variables to appropriate values/ F5 z5 P, b& k; ]
to setup-globals
: A3 f7 h: d& a  set current-light nobody ;; just for now, since there are no lights yet) ?% d# y( n, u0 V8 m. d
  set phase 04 Z  K! n( H1 M- ]7 E
  set num-cars-stopped 0, ?( C3 }9 t! v8 ^( i- w3 }
  set grid-x-inc world-width / grid-size-x
% T9 U( z; ~6 v: f9 N+ u. T  set grid-y-inc world-height / grid-size-y
" e4 ]- y- s& p9 ]; u7 J! i9 M, K: X- z  a4 l5 b
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( U  u6 I- K5 t) p1 s3 @! E+ v3 g
  set acceleration 0.0996 r" p/ m7 K* X- L
end
# `: c5 n9 f. P" y- c! _% T  e5 k% y2 Z: i  t
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, z3 J9 B; ^9 u- J; B
;; and initialize the traffic lights to one setting
  I  T8 `% I# A  D9 W8 `& ^to setup-patches, O! s$ e1 p) {+ s7 A$ I
  ;; initialize the patch-owned variables and color the patches to a base-color
/ R5 z3 h) ]1 W# f$ D  ask patches
+ N" v: [8 q, m3 ?  [3 {) @' J# y7 M7 C0 X$ a) R" X# ^% P
    set intersection? false
4 g; N" b( v3 v. P3 a! E. o    set auto? false
5 B9 M4 N- {4 ^- r3 T" U# M    set green-light-up? true- a# P- N0 d, c/ N. E+ C$ E' x
    set my-row -1
1 Q2 q# l" g0 P$ Z4 Y, B  x    set my-column -13 l: P" h* Z5 z
    set my-phase -1
! P8 F6 M- Z8 z1 A' r1 J; ^; _    set pcolor brown + 3
5 n/ f8 |" W0 }/ }( L, Y  ]
' {1 r* f2 [5 L
: R0 _0 B" {0 G; D' Y  ;; initialize the global variables that hold patch agentsets
0 ~4 s* @  q+ y2 V  set roads patches with
5 g7 K. `8 g* j- P# b3 i    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 e  _2 B# O& X& {! ?
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: x; ?0 L' w1 J" N1 ~; b; b- c  set intersections roads with; q' s: G+ X) Q* Q" b2 T5 S7 |  l- ^
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 S, D9 {1 J: x. D( \
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 B" M1 e" C3 K8 J0 J; r0 q3 ^" Z
  a' O8 O+ E7 P3 u' C  ask roads [ set pcolor white ]7 ]! Y% i5 m$ }, K& o8 F) o
    setup-intersections
* X/ E0 s% I, d9 Kend( o: r9 T# t: p7 c: a$ `! D' C
其中定义道路的句子,如下所示,是什么意思啊?$ Q/ z+ ~9 |" _4 I, z3 @
set roads patches with. n. I* {* {2 d# d( }0 V! I
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 U4 a6 u( M$ i$ h7 J    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! B$ M# h! w/ [8 d. D! X# S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, 2026-4-7 20:32 , Processed in 0.019696 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