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: 9162|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。4 `% [; h/ s" e% R. {: [
netlogo自带的social science--traffic grid这一例子当中,
; A6 \+ ?# c! {globals
  v( G" i% P5 d  d) J[
+ d* v8 |( ]" n  y6 \' }6 T  grid-x-inc               ;; the amount of patches in between two roads in the x direction
! V0 Y: _* m) h* X5 z  grid-y-inc               ;; the amount of patches in between two roads in the y direction
3 r3 N$ N5 C" ]5 ?  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
$ ~: S/ l# m4 w                           ;; it is to accelerate or decelerate
3 D$ w: N0 n. L) W  phase                    ;; keeps track of the phase
2 p' i$ Z  _3 E! c  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure3 J' i3 C) F# g1 N
  current-light            ;; the currently selected light/ P8 j3 a' V/ h( |
2 p: s' l1 {& d1 w" ~
  ;; patch agentsets
$ S) h% j6 f4 b! c1 C" S  intersections ;; agentset containing the patches that are intersections2 i" d7 u! A% M1 X, V
  roads         ;; agentset containing the patches that are roads
9 ]5 ]: S+ t- _! R]7 R. L  q& o: w; U

2 p# v, `& x+ Vturtles-own* U  s+ o$ F' c5 Y4 }: V5 {9 z
[
: s4 l( T2 s( P6 ]# {  speed     ;; the speed of the turtle. h6 P2 p. f$ A! P2 V. o9 V
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right+ C8 f; i5 n" l
  wait-time ;; the amount of time since the last time a turtle has moved
' d+ |  f' N4 H$ u5 T+ s) |]4 x5 Y" p& i8 K  B7 U

; A0 o4 i( q* T, J% Tpatches-own/ i0 g- Z# ?4 m* o  @1 W' v
[
8 r  c0 q: |- C) H! Y  intersection?   ;; true if the patch is at the intersection of two roads% @: J$ H) S/ I/ r) ]# O/ Q
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.1 ]$ T+ Z0 A" l% a
                  ;; false for a non-intersection patches.0 F& a8 |& Z4 U* \7 d( N& @
  my-row          ;; the row of the intersection counting from the upper left corner of the
" S* B6 P0 {! S4 |6 v                  ;; world.  -1 for non-intersection patches.1 w9 ^- [  q, w- Z  a
  my-column       ;; the column of the intersection counting from the upper left corner of the* w$ k& m, w" S
                  ;; world.  -1 for non-intersection patches.$ E# ]. }3 K# z  [( g# o
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
$ K) m5 Q# |( `0 V7 |2 p  auto?           ;; whether or not this intersection will switch automatically.' Z7 {& u" r2 @4 e$ I* Y+ G/ O
                  ;; false for non-intersection patches.
3 q+ D) W8 M* D7 ?7 y: P& P+ O3 M]
" m9 V# @% p" M3 J2 i1 u8 U
5 B, G8 ?$ C, L1 a/ m8 m% s/ `* Y, B, P
;;;;;;;;;;;;;;;;;;;;;;; g) g( ?+ t  m$ e# Z' f
;; Setup Procedures ;;" E" ]; \! Z9 G2 V4 N8 G; x, ~
;;;;;;;;;;;;;;;;;;;;;;: l+ C, l  Y: h$ G+ u
: X3 N; U) P/ k! S" |# d
;; Initialize the display by giving the global and patch variables initial values.
; c* k( j+ D: {' W$ w: L;; Create num-cars of turtles if there are enough road patches for one turtle to! L3 J  q# j. E
;; be created per road patch. Set up the plots.
5 A7 F) c5 H8 c: J0 qto setup! n/ U3 g. O! m- e6 S6 _
  ca  Y/ R( [" k  e: f% H' ?5 j
  setup-globals1 Y: b; ^! `0 Z' y& ^. B

7 E# O9 r9 d, l! k% n4 T  ;; First we ask the patches to draw themselves and set up a few variables
7 v& ^3 z  P8 V9 _5 _  b; C  setup-patches
7 q4 \2 |% l& z9 |* [  make-current one-of intersections8 C  s5 k, ^: F' s
  label-current5 v$ t8 a0 w- q1 M& G

1 I+ y  G; w! m/ w  set-default-shape turtles "car"7 n3 K, d; R6 b2 i9 y% }
( b1 ~3 q2 Q- l: r& t3 `' T+ A5 s
  if (num-cars > count roads)
& l. F6 H/ c% q% V8 h  [
( O$ }/ v  W* ^$ v8 ~' s0 C8 d) {    user-message (word "There are too many cars for the amount of "
% s9 i7 c1 ~* M2 U  \  y$ U- a                       "road.  Either increase the amount of roads ", z! @+ s! z) K  n. e3 o( U
                       "by increasing the GRID-SIZE-X or "1 I+ U1 p) u3 u
                       "GRID-SIZE-Y sliders, or decrease the "4 B6 e  N$ c  O" W1 |1 o
                       "number of cars by lowering the NUMBER slider.\n"( W; z% c0 ]- O) o) o0 M+ Q
                       "The setup has stopped.")
$ j+ _7 L2 ]$ E+ N7 ]7 u    stop* V+ ]' o8 v9 ^; R6 P5 ]) d: U
  ]4 f, }) w: q4 Y0 i
( r5 j& ]) z/ O. }' v+ V
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 _% s8 F1 A4 U, \& C
  crt num-cars  E0 y5 a- W5 q" _
  [" t& X' C, H6 r+ X- S! T8 y
    setup-cars
) M! f0 W6 y; |0 `9 Y    set-car-color
' c6 y5 P" U: ~- I) Y& X    record-data0 m" U" F4 O. q' O6 j9 _
  ]+ z/ H% q0 D) C/ {
( ^& b8 G" d- ~" v. Y/ P6 g
  ;; give the turtles an initial speed
$ _# v& E1 g' g1 I# q  ask turtles [ set-car-speed ]" M: `& ^* o8 ?0 F/ U0 B
* i! ]8 |# t4 A, r% {
  reset-ticks8 }" t8 A7 H' u2 o/ f7 N# b
end
  F+ B9 ^* @+ {
, H; z( M6 Y( @+ G) q3 n" P;; Initialize the global variables to appropriate values
& m3 w3 h- |# q" ~" _to setup-globals% O% Y6 b" O; u0 N$ c' h2 i9 ^
  set current-light nobody ;; just for now, since there are no lights yet3 l6 M) j' {- C. \" r$ l7 X
  set phase 08 y9 {& K" u% K4 |# w
  set num-cars-stopped 0
( L8 b# V7 ^$ E' N. T  set grid-x-inc world-width / grid-size-x5 K" }* m1 I! f
  set grid-y-inc world-height / grid-size-y
2 j+ \9 |9 ~) {5 m; K
: T( X" D0 O- x! M4 R* N6 O  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
- q# s; _# _; Y; A! p  set acceleration 0.099
& L; a. Z- K/ U; |0 u, lend& n" R3 t8 ?$ s. p, h2 \; K$ h

0 ?7 q& A0 @! D% a0 R7 B2 r: k;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 R4 ^$ s" Q5 v. o( g# Y
;; and initialize the traffic lights to one setting* t7 x& G; d7 C& F" [/ y
to setup-patches8 }( Y! H2 w+ ^8 ^) ~* m2 ~
  ;; initialize the patch-owned variables and color the patches to a base-color2 \9 y) M7 F8 x0 Q7 k
  ask patches4 L' M1 s7 |1 U+ S
  [0 J; c0 q- X" L# [8 d8 r- c% A. u
    set intersection? false0 S# J6 ~5 r) S3 p9 \& n* N+ n
    set auto? false9 Q/ ?- T8 L& Y
    set green-light-up? true/ q7 e* f* R! m, j- G- n
    set my-row -1
6 T9 `6 A1 @- t, b/ j    set my-column -1& N; L* |  u- Q$ j& e
    set my-phase -1) K% A7 g: N6 w
    set pcolor brown + 34 g( T: [8 \. T' }! \
  ]
) w6 n  d/ g( B  j2 ?* y4 `8 P4 Q1 B) U: F9 L/ }. i; G# Z
  ;; initialize the global variables that hold patch agentsets
4 D( A3 h4 m5 H+ E8 s  set roads patches with
& T7 h2 b( s+ W, D3 v& y    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& t2 H; l! a  X4 i    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. k, F6 Z  u5 P6 j- [* G- M# c0 t8 h
  set intersections roads with
0 n$ T" ?: c- i8 o    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! \3 [& \; A; j. m8 n
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 D7 ^9 K! ?9 M" [4 i5 A5 O3 J2 F3 Z" A  H1 u6 g
  ask roads [ set pcolor white ]
3 L3 L, J' w+ m+ Q    setup-intersections% W* `) E7 R& w# \2 u
end' ]! v# v0 z( V' e
其中定义道路的句子,如下所示,是什么意思啊?
2 S4 r7 k2 I0 |- U5 M set roads patches with' M$ ]0 f" H% W
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# V  M$ X" }$ {% `- E0 R    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. u! R7 _, f+ P( L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, 2026-3-31 16:59 , Processed in 0.015894 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