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: 10262|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。
9 N( ?+ j5 C* W. X% z# Inetlogo自带的social science--traffic grid这一例子当中,
% W+ B  g5 Q+ u1 Yglobals
/ A) K+ \2 y2 s[
6 A7 I) L: N' I  grid-x-inc               ;; the amount of patches in between two roads in the x direction6 R1 i1 S* v0 m
  grid-y-inc               ;; the amount of patches in between two roads in the y direction1 a/ i$ ~! l7 e9 a; J
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if5 S3 `% y- }  e% i7 H: {
                           ;; it is to accelerate or decelerate
' X, o( a" n+ _) n- q2 j  phase                    ;; keeps track of the phase
/ L# s4 z0 R" ?: I$ w2 k5 S  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure7 C  |# R0 G) q( N: B. V
  current-light            ;; the currently selected light
& }2 L, W) L: O9 I3 x# P
/ N( f; o. _& n: a4 y0 F  ;; patch agentsets7 n  Z1 M6 C( c
  intersections ;; agentset containing the patches that are intersections
: P) [2 y8 u# [/ P; S  roads         ;; agentset containing the patches that are roads; D3 F' P3 g( [! V3 y7 z; n! a
]
4 k4 v% Z& y3 X5 [
: W$ G) n; n7 Q4 U/ P- ^4 c# d. T3 tturtles-own% b$ v4 B- O/ F$ m/ n( n) Q
[7 ~" f2 L) k/ b. w( P
  speed     ;; the speed of the turtle. }; k; U' X; v  s& Y) U
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right. x3 i/ C2 i& W0 I
  wait-time ;; the amount of time since the last time a turtle has moved: ?! J& |4 d- C3 D) v: m
]$ ^5 F; Y4 _! n& x

, x+ `/ ]( B% I' N4 w; @. kpatches-own4 {1 h2 S' l  \7 R) H
[2 b; N$ n4 m1 A7 g1 g3 W; p
  intersection?   ;; true if the patch is at the intersection of two roads) g$ m. I1 r0 @" V) r
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.6 |- p5 m3 {6 ]: \5 Y
                  ;; false for a non-intersection patches.0 _4 L  y+ P: G. @+ l
  my-row          ;; the row of the intersection counting from the upper left corner of the9 V( q+ Z, P# [, D* I/ X1 T* H
                  ;; world.  -1 for non-intersection patches.+ J" ]3 K$ i" b* a& J! [/ K
  my-column       ;; the column of the intersection counting from the upper left corner of the: H6 T0 }* ]& E7 b" f7 W& S& F
                  ;; world.  -1 for non-intersection patches.% L7 K7 `1 e: |" k5 v+ ]
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.' ?) K9 Z2 l# b1 y
  auto?           ;; whether or not this intersection will switch automatically.
' _6 S( F5 J% Y9 C                  ;; false for non-intersection patches.
: i% [; R7 `9 }/ y" Y8 [0 w1 |]6 C. k# _& h( z0 r- l6 o

9 j1 e! ^* P6 Z" v7 j, \: w- {3 z8 A0 k$ r
;;;;;;;;;;;;;;;;;;;;;;6 |% B" }; F/ m% P) W2 G
;; Setup Procedures ;;
1 A9 N/ Z1 q2 X( A, R+ \;;;;;;;;;;;;;;;;;;;;;;6 z1 l1 f( y6 _4 Q

( g2 q+ Q) @) G' p, t+ Z;; Initialize the display by giving the global and patch variables initial values.
4 I- o9 L3 Y8 H! g2 r' X;; Create num-cars of turtles if there are enough road patches for one turtle to( p8 z, ]" B$ r
;; be created per road patch. Set up the plots.
4 r3 v; E# P4 s# k' Oto setup# t8 h7 z( }! A
  ca
& k; e5 F2 b7 b9 K: r4 C  setup-globals3 B9 `- S8 e# `) W

" C. x) ?8 C5 l, Q3 Q  ;; First we ask the patches to draw themselves and set up a few variables* ?8 W. ]' R+ k/ a3 ^# n  d% g! a
  setup-patches; R. ]# [: j. V8 D4 _* F9 O) C
  make-current one-of intersections2 w% s& H# F: X/ Q9 H2 \
  label-current
/ Z7 v, ^' p3 K2 I+ I) T8 ^% x% W, j) H  _. M7 r
  set-default-shape turtles "car"
1 n) c! ?' N7 `( ]! [
* ^2 B- o7 I4 B; r, a  if (num-cars > count roads)9 O- n. o) X# f9 ?
  [" R( [# F$ q" e2 A: r' C: i8 Q: y
    user-message (word "There are too many cars for the amount of "" X9 C" o! H& A/ q" F8 h
                       "road.  Either increase the amount of roads "3 J# L  @$ z% A9 l
                       "by increasing the GRID-SIZE-X or "5 W3 R2 F# x3 n; l1 C0 P3 P! S
                       "GRID-SIZE-Y sliders, or decrease the "
/ N  w" _' w* F9 f7 G  Q! i% [                       "number of cars by lowering the NUMBER slider.\n"0 r& r$ D4 b3 G+ }% L5 \, S4 K
                       "The setup has stopped.")/ ~+ ]- I3 Y& b! z
    stop
2 I) @$ z* ~* L" B: O8 E$ k: g  ]
+ y  O8 c5 P0 x9 v1 c$ n2 N" y) }) d( J* f* U. h8 `
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. _$ r# Z* P5 E! d  O  @% f: U  crt num-cars
& U4 Z1 z# H/ F0 e* j! s1 x  [* l) M! Q1 b2 Q; J2 w- M6 e
    setup-cars. t: W, b% `3 g+ o
    set-car-color- n9 {1 u9 K9 O9 k# W( S& m3 V& \; ]+ F
    record-data
2 L( S/ u6 i; b& ^/ p0 w1 l  ]
8 _9 _- M* Z0 P2 C( b
* ]- }$ C( O4 @% O# I! W  ;; give the turtles an initial speed
+ w, s1 G2 r5 E0 ]# [0 a( ]# S1 h  ask turtles [ set-car-speed ]/ v6 n2 F/ x0 w8 E* K

4 t" E9 r: N! Y2 L; L  reset-ticks: O( ?# o. M1 \) ], b, ~* C3 G* s
end
. }$ O- k! ~+ _0 W1 Q, |; m" F+ K9 ~) q% E  W
;; Initialize the global variables to appropriate values" a( g( I( O6 m& b+ W# t+ ?
to setup-globals! v) V( U! N- C: o. ~
  set current-light nobody ;; just for now, since there are no lights yet" j4 l" h- ?* ?) `7 Y
  set phase 02 Q$ a2 y& K, S. u0 _/ g2 n
  set num-cars-stopped 0$ _( Z7 c4 B2 r, v4 ~
  set grid-x-inc world-width / grid-size-x
6 Y+ ]  ^! ]* L+ F* i  set grid-y-inc world-height / grid-size-y+ k. J% k, A! W+ v/ \8 u4 q

# L+ H$ v7 R0 P2 M0 ^! Q, d  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
8 ^6 U* }& x7 `$ I! Q7 T! i  set acceleration 0.0999 e9 \' c$ @, W+ ^
end
, Z- D  J2 e6 B- t5 G+ j( j' o. n9 }
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 e* f6 i* Q9 h6 Q5 I- d/ w
;; and initialize the traffic lights to one setting
9 f7 C- n* U' s% {# V$ k$ Gto setup-patches" U: y+ F; N1 k1 N
  ;; initialize the patch-owned variables and color the patches to a base-color; g9 E9 R0 _5 H( w
  ask patches
* h- c+ H9 ^4 t9 k/ w  [' |: M- i; C( u3 L4 b) m# E
    set intersection? false( B& _' H  i6 h% m$ W
    set auto? false9 v( h& K3 A* B* Z7 {
    set green-light-up? true( ^# a' s) m! {+ K/ K) i: R4 W; a
    set my-row -12 u  [( r! c+ l3 T0 v& J% y- q
    set my-column -1
. b; O; h6 E2 u3 B( V& j5 W- P# ~    set my-phase -15 }) `, U& B7 z6 ~& ?5 M5 `( r. }
    set pcolor brown + 3$ p! G$ Y: s# \2 d
  ]9 N4 d% P- V' k, P+ Y

5 {# I( z" [* }4 i$ |8 ^( U- l  ;; initialize the global variables that hold patch agentsets
3 b6 g5 _5 n" t  set roads patches with
3 T+ S3 V6 O. t+ L6 V    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ d& X& u$ g: R( _3 K
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 b  m: Z5 d. M6 b4 h  set intersections roads with
6 j! H$ N8 N3 K3 ?    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 B6 v7 P8 X) \0 }    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ j7 d' u% i& T% G' z+ q) g) B7 x9 a6 l8 R0 z% t
  ask roads [ set pcolor white ]
% \  m: U: j" m' Q    setup-intersections3 S* z& n+ e5 @
end! z7 u. }) \  m6 D5 Q7 }
其中定义道路的句子,如下所示,是什么意思啊?  ?# C1 y. \8 k& y) H
set roads patches with
1 f/ }- [7 F  h- x5 u$ P    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 D# Z* Z  d2 H  e" V    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" H& Y) y. q  p  \& \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, 2026-5-26 23:15 , Processed in 0.014045 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