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: 8185|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。& M# U& D) _7 ?' J
netlogo自带的social science--traffic grid这一例子当中,' q( T( t% }% e0 O2 V
globals$ b; j0 M  l5 @1 l/ p
[+ Q0 R. }. e" I2 l
  grid-x-inc               ;; the amount of patches in between two roads in the x direction. o& s1 L2 x1 s5 }5 u0 U' Q
  grid-y-inc               ;; the amount of patches in between two roads in the y direction3 y7 r! V1 y, L7 h% I2 _& l% K* y
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
/ y/ u3 ~( c2 H9 K+ T$ H7 m- g                           ;; it is to accelerate or decelerate4 `# d! T+ g( g" d0 u* ?
  phase                    ;; keeps track of the phase
& Y+ M- u4 s# q  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
5 g9 D6 \5 _; i( }& {& _  current-light            ;; the currently selected light
+ c' m& M0 \- L; m3 J) T7 |+ V& t$ T
  ;; patch agentsets) V4 w  o( W5 ~' b! W: p9 t4 @: Q  ?
  intersections ;; agentset containing the patches that are intersections* [5 F( s) Q& G
  roads         ;; agentset containing the patches that are roads
1 k! v& i( H4 o. X+ Z7 t]
. v2 B* a8 r& p7 y6 o# C& x9 u) h; R% ~4 ~0 |2 ^
turtles-own2 i8 P( B. R6 T% R
[
7 R7 y: o; o* T3 b( N! O  speed     ;; the speed of the turtle
4 ~6 ]) _; U5 \! ]# @: o5 z& _$ d  up-car?   ;; true if the turtle moves downwards and false if it moves to the right) H+ S3 T* r. R. M$ Q/ \" J9 T
  wait-time ;; the amount of time since the last time a turtle has moved
" A  `* @* Q6 C& V]( C$ H4 P$ E8 t+ {6 j) X
5 C$ e9 H- |: [$ F& S6 F
patches-own
* \# G; P9 k/ D9 e[' U3 b% `; j% g- [5 O# p
  intersection?   ;; true if the patch is at the intersection of two roads
- E& g5 @" Y/ O; A( E9 J, i  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.% o" u. a9 P* r5 ^& ^5 _
                  ;; false for a non-intersection patches.
# G4 I7 L5 z1 S( f4 b# L. L  my-row          ;; the row of the intersection counting from the upper left corner of the
6 U3 y3 d1 w* d: X9 e  x% P- |/ S                  ;; world.  -1 for non-intersection patches.
  S/ h4 M/ J% P, X  b; ~( J7 S$ i  my-column       ;; the column of the intersection counting from the upper left corner of the
( @7 I# a4 Y& Q0 ?+ H3 S5 I! o                  ;; world.  -1 for non-intersection patches.
1 l. K! C' _# [, K  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
9 ~3 h% j0 i; b9 `: n3 B0 W$ [) q4 g  auto?           ;; whether or not this intersection will switch automatically.
9 G  {5 W  |8 G' \! U0 U9 }                  ;; false for non-intersection patches.9 F) H" I: A" ?2 b
]: N$ y: h* m% U/ r! Q
( T3 L4 Y0 w: P7 `3 ~7 }  ]
# z: T. V/ z& V0 {0 \- w1 M
;;;;;;;;;;;;;;;;;;;;;;& K2 V( f+ @$ t) n9 o
;; Setup Procedures ;;0 J: z8 d. x9 e
;;;;;;;;;;;;;;;;;;;;;;! [# e, q, }( r1 V

( X2 ^9 D- }  h;; Initialize the display by giving the global and patch variables initial values.. S1 `$ w( w1 J+ f9 S8 ^! J
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 P; L2 \" H9 Z9 b; C+ s;; be created per road patch. Set up the plots.
# i( E% h$ b9 q% dto setup
; _0 n0 u9 C# Z  g% A6 e' z% P  ca2 \; R$ P* C8 F; Q. ]! A
  setup-globals0 N7 h& w4 A- Y( ^! R' e/ a

+ N% D, q4 }7 `. ?- |& Y; i+ E/ R  ;; First we ask the patches to draw themselves and set up a few variables
& ^/ v; y5 \5 r( I. O- Y  setup-patches
. g  X7 b, @* t2 W6 F) A1 t* V  make-current one-of intersections
- J7 @2 K3 r- ^9 W, K6 s# q  label-current! K4 G+ m& Y0 I5 Y  \
% G0 y. D& Z2 A! B$ Z
  set-default-shape turtles "car"
7 D2 @& H+ y0 i2 g
! V7 x; |" g' i% Y/ x  if (num-cars > count roads)4 b: \" t( v, c! ^
  [+ w$ U3 Y: B2 n2 O) X* t5 q; Y. w
    user-message (word "There are too many cars for the amount of "
, P% C# ^2 z+ v" [& \  Y4 [2 x                       "road.  Either increase the amount of roads "9 X- u/ p; y+ q
                       "by increasing the GRID-SIZE-X or "
0 d3 D" Q7 u; Y8 n, d( n; p                       "GRID-SIZE-Y sliders, or decrease the "
8 j' E+ @( \  Q; r! y- {: R* _                       "number of cars by lowering the NUMBER slider.\n"8 a- |4 K$ `; d
                       "The setup has stopped.")! x8 K% M# q9 Q2 e# o; M
    stop- f# ^. [- T. i/ N. b% z5 E3 p
  ]
0 p/ Y) }; w) c: ^1 A9 V
2 E* ?* T4 y# ]! Y7 ~" M  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 H% |, m) R) O, x) ?2 [3 n
  crt num-cars
* X! E8 t( ]" p: z7 F/ u  [
: s, y5 u+ ?6 p. F    setup-cars
' y2 X- c: v8 Q, B    set-car-color3 P9 p. D$ q9 t& Y  R* ]
    record-data! U. _6 p, I! y2 ~# `( q9 z& a5 ]
  ]! n9 p2 o5 J/ y9 C% x

) A, y# S8 T  d; T& f  ;; give the turtles an initial speed7 _/ K* m6 L9 [7 J& U7 K* a3 k. h
  ask turtles [ set-car-speed ]
% N6 u+ g4 e0 i& E2 x9 s$ v7 r' |, i1 W" |0 k! w# e
  reset-ticks: A  B/ o( d+ W
end& j' h' _! y. d& Y( Z7 Z  {

9 C0 X) `# X# r# ^;; Initialize the global variables to appropriate values' J5 b& f7 Z7 P. `
to setup-globals* ~% z$ D6 D- ^3 h
  set current-light nobody ;; just for now, since there are no lights yet
2 J* u" p  M  `) o  set phase 0
8 j" _" n  q! [  d- W, m0 w9 q! c9 m  set num-cars-stopped 0
' P0 x$ x5 [$ E$ b; @2 L  c  set grid-x-inc world-width / grid-size-x
7 H# i8 ]* V, P% D  set grid-y-inc world-height / grid-size-y5 M% ~1 C/ ?2 K  I% _

' i. C, i5 h' P, e0 i$ D& w, F9 `  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* R) p9 E# P; b0 @. Z% W" p
  set acceleration 0.099# `8 j9 _+ `* i  E4 k7 y: Q' M/ F
end
8 L" h5 t7 F" x
: k4 I* _2 x  v% C% R2 I;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 P( |* Y) v* N7 `
;; and initialize the traffic lights to one setting# T. z4 D( ?& [+ z! D
to setup-patches+ _. w0 f( g1 P! q+ s+ j9 M: r* {
  ;; initialize the patch-owned variables and color the patches to a base-color% G2 e5 d5 d1 [: e1 \. m
  ask patches1 o1 I5 i1 ]7 j8 B, J7 A9 F
  [
6 K1 P# G1 f1 T" I8 m: _    set intersection? false
" Q0 N) c( b' X% I  `2 r* i. J; f    set auto? false, s4 W% K* h+ w" C8 B
    set green-light-up? true
/ O1 M: l# [9 F$ i' t2 r" U2 k    set my-row -12 h+ E6 W+ x: a& p/ @* Z
    set my-column -1+ y! j: D, d$ b; c5 t& g
    set my-phase -1
' |2 ?1 H" N( Q$ Z( }. F& L+ p    set pcolor brown + 3
: q  o8 a7 l$ i# O1 w  ]- D) z9 Y0 ~9 o' p) q, g! R. z
. Q) z% \0 e% K4 c
  ;; initialize the global variables that hold patch agentsets" }5 Y" `6 l$ N. g( B
  set roads patches with/ L! {" a7 i- ?0 `, p
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( k# P( M/ `; r) V, _    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# O4 C5 d2 r- o2 m
  set intersections roads with: G& K# F% [# _: W" i( P: W5 S
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( f$ A# V8 O  }* c0 s
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: f/ t" e! Y" s; ~' H6 A: ~, {' b  l& [( z& ^/ F0 o
  ask roads [ set pcolor white ]
: Y: [* r$ f' A! l+ w9 L* v    setup-intersections$ C# N2 |- z* \; N
end
. @0 v* o# V- ^+ ~其中定义道路的句子,如下所示,是什么意思啊?  R7 F. l" \# }! Z! e
set roads patches with
+ V* W  m& `3 e# E, |4 w    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 ^! W. r" v2 q2 H
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ d/ |; b" @) W" |8 R% F1 w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, 2026-2-5 13:57 , Processed in 0.015781 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