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: 10720|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。. D! O/ `6 O4 G+ a' w
netlogo自带的social science--traffic grid这一例子当中,
3 p% O9 Q7 R6 X% ]globals7 e2 x# V# E6 o9 D
[
  P) v4 N( ?* b0 E2 d  grid-x-inc               ;; the amount of patches in between two roads in the x direction. Y$ |3 p4 Q- U% V  s
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
9 V/ e+ s( h' x3 n  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
/ j6 _  m9 k; d8 g2 x                           ;; it is to accelerate or decelerate
. N1 ]9 v$ y1 X. Z& k& c  phase                    ;; keeps track of the phase+ W" V3 O. Q, C+ I; p5 V1 p
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
8 r! w( R& z3 h# L  current-light            ;; the currently selected light
) J, @7 L4 {* r* X  b% P* {) O' R0 E1 Z
  ;; patch agentsets
# T3 d" k7 s$ V/ b5 b) h- [4 U  intersections ;; agentset containing the patches that are intersections
1 D- L- H3 k% Z* j& Z. I  roads         ;; agentset containing the patches that are roads" K5 \( D/ p  g; G$ u
]
8 W3 l. D* ~4 t) g" X9 P6 r3 d
turtles-own
0 \% N7 X$ K! g& s[
0 w- S2 t( v& _6 \' F! [/ L/ t  speed     ;; the speed of the turtle
) V3 }/ A: W1 e- A" e  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
7 Q- B9 |0 ]: X. {  wait-time ;; the amount of time since the last time a turtle has moved
" e# m, I) ~8 m" t& q7 O( l]
& e1 b2 I' V$ n; Y
, X6 k* o# N& C1 [/ K) E, C* Upatches-own  }6 d$ Z9 p4 n: |8 k8 j& @: S
[
9 Z! r: I  u& Q, z" S  intersection?   ;; true if the patch is at the intersection of two roads
' `9 p; O& {- M! X+ T; t  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.) h2 v+ ^$ T9 f. ?2 T/ a8 ^% O1 Z
                  ;; false for a non-intersection patches.0 y( `+ V8 d  [8 \, w" {
  my-row          ;; the row of the intersection counting from the upper left corner of the
: _! `: Z3 z/ \$ [                  ;; world.  -1 for non-intersection patches.7 q# C$ i# {$ G
  my-column       ;; the column of the intersection counting from the upper left corner of the
7 Q% W1 H. s1 g                  ;; world.  -1 for non-intersection patches.0 L- a/ \! r) v8 z
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.; C6 c# m* H& a) e0 Q, w. q
  auto?           ;; whether or not this intersection will switch automatically.9 X+ D  O" y+ _' C9 R/ S6 M) \
                  ;; false for non-intersection patches.' b9 L9 w; U& g  d) J0 u0 B( W
]3 o5 e7 k( @' A+ G4 s" Y2 S
1 u( K6 }; P5 N( o6 n

: n# J1 o# L( z. G1 S;;;;;;;;;;;;;;;;;;;;;;
4 Q$ b& A+ h8 j' s;; Setup Procedures ;;% ?- `& t& d# x  R
;;;;;;;;;;;;;;;;;;;;;;4 t3 l. g. `* y# q, [9 n6 v
1 @4 [0 ?( n% [1 D8 O
;; Initialize the display by giving the global and patch variables initial values.
; Q/ u# p, H+ X$ O;; Create num-cars of turtles if there are enough road patches for one turtle to4 c* H+ D/ l/ u7 O/ L6 Z2 K
;; be created per road patch. Set up the plots.
7 U) }" S. A* g1 ]to setup7 T' z! w0 u6 B: _" ?
  ca
6 U: c3 _( O8 V) p- P: L  setup-globals5 O# J) k+ r& E$ `! O

' i1 x1 o+ {4 E  ;; First we ask the patches to draw themselves and set up a few variables
/ y) R2 n+ ]/ W* F4 q% N  setup-patches3 u, h4 ~" V1 I! W- K5 I
  make-current one-of intersections
6 D$ H& o/ q# d. n1 ?  label-current
  g) \# L$ u& T/ b/ P6 k. p" Z
- w( K5 F  E5 U0 C  set-default-shape turtles "car"7 m# A: J# n# \0 H7 R) Y% E7 ~
9 m/ t1 Z6 v7 T7 r1 q
  if (num-cars > count roads)
8 p/ Y* R' ~4 u& T  [- ]. @6 f& X& x2 t7 s4 y$ N
    user-message (word "There are too many cars for the amount of "
' t- n4 Z' o: I: ]* Z" P                       "road.  Either increase the amount of roads "
8 v, Q) T8 j" u1 \                       "by increasing the GRID-SIZE-X or "
7 o- V* g/ {' I+ A                       "GRID-SIZE-Y sliders, or decrease the "% _! Z" j$ k  ~1 B+ v$ C
                       "number of cars by lowering the NUMBER slider.\n"  x6 A& f6 e1 _. h0 t
                       "The setup has stopped.")
8 v* G! Z  J/ E* J  Q6 ^    stop
- k! D( j5 ~- J% `  ]" A$ ]& z. R5 _! Q& V% ~0 g
& Q+ X3 ~; I" f5 @, ^. r
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ S4 X. M$ `, V2 s' S9 Z  crt num-cars
3 h* @# X0 c2 Q  \- c) Z3 x  [. Z. q+ N/ u) Z+ P0 ]/ K
    setup-cars) J' l- D$ ~% ~- j! G
    set-car-color
, J. V& v! z# j' Z+ C3 U, m    record-data
$ A0 f9 c3 B& v- _  t# t: l  ]; k9 L: H7 P0 G( M& z1 q) G$ U

9 z4 X# v9 ~' c6 D; n! ^  ;; give the turtles an initial speed) z4 N8 r1 V* ?( t/ P
  ask turtles [ set-car-speed ]( g; [. \8 H# b# P
) G7 e$ [) A5 b7 b8 }
  reset-ticks
2 K, p' S# k. ]end8 m6 i/ m! K9 p

! X: M3 v8 a2 v' L& D# M;; Initialize the global variables to appropriate values9 {* ?+ T8 n* Y0 h/ o! M
to setup-globals
! v) Q: L! F9 j; G  set current-light nobody ;; just for now, since there are no lights yet
6 c% V8 q! |0 [2 M4 S  set phase 0
5 K* m( g$ X1 Z* z0 ?$ C' w- ^. I  set num-cars-stopped 0
, t* w; z6 ]) }) `$ m2 b  set grid-x-inc world-width / grid-size-x
- W/ v/ x! L& Z3 s& v  set grid-y-inc world-height / grid-size-y6 V1 B" \; S2 l" b) E" {

. q! k1 l% }7 o% h- q  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 j! E( L# Z6 d0 e  S  set acceleration 0.099
" `* X8 G! A: s* R; P  p, rend
! S9 T3 Z- }+ b) Y, w  @
' G, ?$ W* F& g! w;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
  a" o8 D* W( m% c0 b* f3 @;; and initialize the traffic lights to one setting
6 \7 i% E- B& c* \/ i" Yto setup-patches
* G9 @2 g( L# Z4 X% \2 s  ;; initialize the patch-owned variables and color the patches to a base-color
( W, R  f) `! V& K" d$ Q$ v: a  ask patches
  q9 E1 E/ I& u# j5 {  [9 G: s9 I* w) X/ R
    set intersection? false
# x  A. M' G( B2 \( ?7 b    set auto? false
  R6 w% E. Y5 R& ^    set green-light-up? true* w0 y% v+ t3 i% B& P" I! m( W
    set my-row -1
- u+ c& q3 U& G2 R, }% U1 T5 C1 R    set my-column -1" b& ~. b! U( p
    set my-phase -1# c& h! L  v; f. u
    set pcolor brown + 3
* `- b; e- L" V  ]% H. Z- k% O; H! K, c  [

  x2 \+ `4 V2 s* p0 C/ U, ?7 y  ;; initialize the global variables that hold patch agentsets' z% {: x5 H7 ]3 r' u0 E" k
  set roads patches with9 {' q7 g1 y# O- j( ^$ y
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) M" J1 q0 }4 o( _
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 Q9 ~5 R/ X  G  b
  set intersections roads with
+ Y- x2 o. h% I: I5 T    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) n6 T) o8 Q3 y) t  I: {
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: b8 S+ {+ D" _$ o
* g& {  f- J+ |+ i
  ask roads [ set pcolor white ]
. D6 j* l- P* s1 ?7 i1 m    setup-intersections
+ z" s8 F! J8 [1 D; [0 Kend7 D( H4 R% S8 S/ x$ z
其中定义道路的句子,如下所示,是什么意思啊?, O' L& F$ U7 A! c+ Z- [1 b
set roads patches with
* T6 ^* }. u5 b0 A' U    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 Q3 P( x( ?* j6 a3 }+ {    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# D, Y9 [! @2 Q
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, 2026-6-22 08:03 , Processed in 0.014906 second(s), 15 queries .

Powered by Discuz! X3.4 Licensed

© 2001-2017 Comsenz Inc.

快速回复 返回顶部 返回列表