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: 7940|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。. q# w3 |1 S( g" T  X1 p. n. l
netlogo自带的social science--traffic grid这一例子当中,7 `7 a, T6 Z1 a) v2 x9 P
globals
( T' i8 }8 I' F[6 U7 h* j) r8 {+ M0 p
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
1 B) k1 V# c$ J) G: R( K  grid-y-inc               ;; the amount of patches in between two roads in the y direction
1 N4 b8 {; k& `5 ?% i1 [; S  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
4 ]$ B# O) g2 U8 |! y                           ;; it is to accelerate or decelerate
, q6 ?+ T: g& i% I  phase                    ;; keeps track of the phase
2 N+ q$ w. q( M: v: A: t; {. y) U' ^  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
' G# u8 ^! [+ o) J) j  current-light            ;; the currently selected light
/ b$ [) ]+ X! Y2 l
+ q9 n9 d3 S5 l3 |$ O" X$ Y  ;; patch agentsets
/ \" Z) |% {4 @- F) u  intersections ;; agentset containing the patches that are intersections
( _2 |+ _! Q, m! E  roads         ;; agentset containing the patches that are roads
# z. e1 V/ K" p0 Z# J* `6 ]]) J  n' e0 I, [( X8 z

: [( U: J1 H8 _; U% L# L3 {turtles-own8 @7 f9 c6 q( T' w) w# x
[
; ^1 c8 ~, o) [; ^0 L6 a  speed     ;; the speed of the turtle
% ~6 R5 c7 n5 b1 k: T% W5 r( a( Y  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
- \# Y7 |# A2 m% B  G. p  wait-time ;; the amount of time since the last time a turtle has moved+ l- Q# d. E* c' m* [7 i5 [* H
]/ n, V( z/ M1 f3 y
- Y0 L% O- x, `* B3 g% G
patches-own
9 r8 l: {0 i2 d2 v# h& W# I& r  \[/ U# N: `, [8 A' \3 A% a( \
  intersection?   ;; true if the patch is at the intersection of two roads4 W8 y$ Y4 L3 I7 E4 h& H; O& W4 k5 z
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.9 a& y, ]) M( c: M+ w; C
                  ;; false for a non-intersection patches.* `$ R0 W+ x7 Y* r0 F
  my-row          ;; the row of the intersection counting from the upper left corner of the
9 A- K, ^3 d# h0 y9 u, B* ~+ Y' p$ K                  ;; world.  -1 for non-intersection patches.
8 i, P" U+ e$ f+ h1 l! g  my-column       ;; the column of the intersection counting from the upper left corner of the% K5 T7 s& S) S( m' q' X; [& q
                  ;; world.  -1 for non-intersection patches.# b& o1 m# i5 S2 i2 T
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.8 B) K: a, c" o" e! L, C
  auto?           ;; whether or not this intersection will switch automatically.
) K# Y$ f& t3 W9 c6 h& }                  ;; false for non-intersection patches.! V8 e  Q5 z0 [3 G3 I8 x4 Z0 t0 Q/ I; A7 C
]( J# ~% |! F3 r/ M9 U& S% o
; V/ Z$ h8 Z0 s3 Y4 v6 x' V4 f

! y8 f9 y) @/ W) R' e7 w;;;;;;;;;;;;;;;;;;;;;;5 h( n# M5 E- w+ d4 `/ {
;; Setup Procedures ;;! Q* I, s! Q: I) p) `  m. R5 c( [
;;;;;;;;;;;;;;;;;;;;;;
3 l) t1 F, C/ _. u7 F* F! N
7 @. S3 {% u* T* l' }4 M;; Initialize the display by giving the global and patch variables initial values.
4 t! `/ G* S/ e+ I; e5 r;; Create num-cars of turtles if there are enough road patches for one turtle to
7 o7 q% [& G# M5 R;; be created per road patch. Set up the plots.; W' c! Q5 e; y; q$ `6 S0 V
to setup
4 U2 o0 E9 ]3 k( @# J8 `  ca3 e4 E! |; u1 |
  setup-globals. \7 [. U$ g4 K9 L$ q

0 i- I1 S! j4 m7 a& w  ;; First we ask the patches to draw themselves and set up a few variables) Q3 P' ]+ f2 s
  setup-patches; K2 S; Z$ g( ~' z# q  u7 C
  make-current one-of intersections* \4 M% S1 @8 q7 E5 G
  label-current
* l* m$ \) G6 C4 i& w" s6 m7 e3 w0 h; [
  set-default-shape turtles "car"9 B1 Z2 g8 l/ K  C6 x; u* I- O# q
/ E1 x9 f( n4 M0 N2 f
  if (num-cars > count roads)) d6 J+ }5 X0 ~; W! O
  [
# _6 N- G6 C! Y; f% ^" M. {    user-message (word "There are too many cars for the amount of "
* g. K% D6 Z3 q+ U                       "road.  Either increase the amount of roads "
( Y, e& \. V, y, r                       "by increasing the GRID-SIZE-X or "1 Y/ D- |* F! {- k1 q( x
                       "GRID-SIZE-Y sliders, or decrease the "
0 g. \8 P& h) P& c0 ^5 l                       "number of cars by lowering the NUMBER slider.\n"% X$ ?3 N* M  `) y, G9 t
                       "The setup has stopped.")
9 C# h& i- Q" Q    stop3 _' o+ c3 u- Q6 E) f# F" M
  ]" l+ @4 |( h. @0 I+ K; O

9 }: B  A  v: Z% m% p$ f  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ J5 q7 P+ }6 _  crt num-cars
, F  f& D" g" m  [
6 i# t$ `9 p; q8 {7 e- }" ^/ R! t    setup-cars% A8 Q2 ~$ G  P8 w
    set-car-color8 t; g$ Q" F) B$ x+ f
    record-data
' b  K/ D5 w: Y/ S) s3 V  ]: x0 n# j/ _1 A$ l# [2 a

( h; m7 X6 p5 r' D$ [& w  ;; give the turtles an initial speed
3 w/ M9 {6 f/ U, m  ask turtles [ set-car-speed ]
) t0 S+ X, {3 Z6 T: d
, p+ j! x; Z/ i, W. b# |  reset-ticks
7 o* I; E& t5 z4 U1 }end
9 _* Y' @" Y, z$ m% o8 _2 Q6 d2 }4 w
;; Initialize the global variables to appropriate values& Q& ?0 i9 W# M$ p. U* i
to setup-globals
* j$ E% r$ {6 ?7 x8 R  G  set current-light nobody ;; just for now, since there are no lights yet; O9 U& c% F: K0 i" e9 f
  set phase 0
* J* a/ R- s; f  C5 U- L( B  set num-cars-stopped 0
- m" }% t# l. L( B) `/ L  set grid-x-inc world-width / grid-size-x
& T6 ?4 n5 V# F# V) V5 L  set grid-y-inc world-height / grid-size-y$ K  V1 w8 G; U" g( w! M' \' D

6 \* i7 A, o# a+ ^. r8 k! B+ g4 O  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# G; p4 ?$ L" B3 t( ?  set acceleration 0.099
4 B; k9 g$ _& @- {# J+ ^end
8 Z$ Z5 Y0 O0 F' K. a  Z1 \5 L/ P+ L8 \
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! ]: t: h& X  S, _7 s9 v1 Y9 }
;; and initialize the traffic lights to one setting
' S: D6 {$ L" d8 I% _' pto setup-patches
/ C' v( \' A* ^& j8 R5 p8 h5 ]  ;; initialize the patch-owned variables and color the patches to a base-color6 f. w: @5 {/ Z- }- P
  ask patches
0 E( t8 k! S, W  [
% V& V) H  S% T    set intersection? false
# n- I- ]$ W3 e: L    set auto? false# o: W0 p% w5 b, ?& H/ r5 I
    set green-light-up? true
% u+ F& y2 w1 d  T" x    set my-row -13 H- C. j6 x7 t( j" h  y& I  p" j+ b
    set my-column -1
: A1 B% f3 _  k    set my-phase -1( I% a. }$ R* k# Q3 @8 E
    set pcolor brown + 3
2 \; b1 S* P; K9 g$ e2 a  ]4 a4 {* N4 ]( s8 {, }

8 Q; t1 d& I# y6 P' M' V- c  ;; initialize the global variables that hold patch agentsets2 K, O( f8 I& I1 F  m" L4 i# K
  set roads patches with
& q6 r, \' }3 a. Q  p2 g2 B    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 X: O, h) w  h5 g3 j$ q6 Y
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 n' Q8 V1 ^' l0 R3 K+ u  u8 U+ a
  set intersections roads with9 }, Q" X# k* {+ j( X) d+ Z) [& J
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( t( X- U, A; F# o3 {
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. T/ I4 [( ~% ~# j1 u

5 m" H  O. V1 l  ask roads [ set pcolor white ]& U# @8 T8 ]) @  e" j
    setup-intersections$ H+ u7 K  c1 ]. u/ T6 j
end2 V& D" Q& K) `; q; `$ T
其中定义道路的句子,如下所示,是什么意思啊?
# F; s  j# `5 q; H  z! ~ set roads patches with
+ v8 I8 d- j- t& o0 v    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; b  }+ g# ]' P1 q
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 P# K5 _2 V% D9 T- F# g; Y# q2 M
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, 2026-1-24 03:05 , Processed in 0.017348 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