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: 10405|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。' V# \' S8 M7 r2 x, \, g: s
netlogo自带的social science--traffic grid这一例子当中,
! t; G2 v  T7 i$ U0 |! nglobals; b5 b: V- i) [! H$ x' n% [, K% w
[7 X/ [6 l9 m+ m8 b1 h& [
  grid-x-inc               ;; the amount of patches in between two roads in the x direction7 p" q4 l! e0 r% J. U, N7 _
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
4 i8 z! M1 }0 h  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
, u: e3 e; B" B: P# Z                           ;; it is to accelerate or decelerate. @* O& }; K" X. o) }7 o
  phase                    ;; keeps track of the phase
' _3 `# @) B( n6 |+ F# b  I  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure9 P- ]1 B/ `  F$ o  a8 i* v+ V/ Y
  current-light            ;; the currently selected light
/ C7 G- K8 N" g4 }, ]+ g) o2 k9 G& o& o5 }. r& n
  ;; patch agentsets
- [& L+ F3 d# u# |( q( N, Q$ b  intersections ;; agentset containing the patches that are intersections
; r' E5 @4 N% V+ j) f. n5 X' }  roads         ;; agentset containing the patches that are roads
1 m; @3 i1 J% z0 O]
8 H! w2 K3 P* B% G6 d
$ S7 H7 s  i5 a7 C1 }3 X$ M5 Q+ Iturtles-own. S, n% l3 r$ u" ]) `
[
/ t4 m5 W1 K% D' k  speed     ;; the speed of the turtle% Y; @9 s  G# W4 a
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
4 Q( _+ |& t) c# k) \7 ?  wait-time ;; the amount of time since the last time a turtle has moved
" B5 J1 {7 f2 m: ]2 z! b5 R]/ s( \& u2 f. w3 N0 }1 d* T, f

+ V. j6 c# `7 {) B" W: wpatches-own, T5 l6 B, q& L4 C0 H& }* t" }
[2 F% A, b" X. m' g& v5 g  l
  intersection?   ;; true if the patch is at the intersection of two roads( C2 X+ T$ j# H- I' g5 X& I
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.$ ~9 i" [) n( n9 s0 T
                  ;; false for a non-intersection patches.
/ v  W2 e) C6 X  my-row          ;; the row of the intersection counting from the upper left corner of the4 _1 ^3 f' J) G  O) d* I, U
                  ;; world.  -1 for non-intersection patches.
0 y) Z# R  U  `9 @- }  my-column       ;; the column of the intersection counting from the upper left corner of the
* c. H; ~. |' }$ w2 ]$ o) y                  ;; world.  -1 for non-intersection patches.. _* H6 j5 p5 i. b9 ?
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
( @8 l0 L. z+ H% [  auto?           ;; whether or not this intersection will switch automatically.
5 T4 a# U+ U6 m/ K8 c7 _                  ;; false for non-intersection patches.. |* y! b' J  h( H& g! z
]
. R; B" ^7 j& F* O$ |2 P7 ?. I! s8 x" x7 {& B* g, T: e$ d

4 m5 |0 p9 l+ C+ @;;;;;;;;;;;;;;;;;;;;;;
8 f" }4 E+ K  Z& l1 T$ v1 w;; Setup Procedures ;;
" f/ Q2 t5 @8 l& S;;;;;;;;;;;;;;;;;;;;;;
( f/ |6 n. b! d( W- l8 B( f' X& ^' T
;; Initialize the display by giving the global and patch variables initial values.
. {( w/ y6 `0 K; o- |;; Create num-cars of turtles if there are enough road patches for one turtle to5 G5 @4 M( ^# m7 b1 I. g4 `/ J2 b
;; be created per road patch. Set up the plots./ w3 W$ \& p" O7 H; R
to setup
; z" ?9 b: }+ S" v5 y- N; }9 b* S  ca3 a3 @+ k. P4 T  d; y
  setup-globals& q+ ]$ p7 u' g* k  @  J

3 a9 |. y1 K* s0 \3 p  ;; First we ask the patches to draw themselves and set up a few variables$ h) l( z; I" Y- ?/ L3 r  E+ E8 f5 s
  setup-patches
1 I0 e  R4 F+ p  X; r& S9 n) C" D+ A  make-current one-of intersections
1 N! @7 Q, a/ T7 Z5 j  label-current0 V3 }: e3 F0 l0 S, `" i

3 h! t- E  I8 P$ ^# H  set-default-shape turtles "car"
, H7 p- t( u$ q8 A* C! [- S
5 u* o8 n+ I; P6 x2 |2 W8 l! l  if (num-cars > count roads)3 l- f' j: o3 l  y+ u
  [: J! t( N. s2 Z. z
    user-message (word "There are too many cars for the amount of "
3 N0 U; _# O& k8 ?                       "road.  Either increase the amount of roads "
* V. @4 R$ D: ?% }* r/ T                       "by increasing the GRID-SIZE-X or "( e. @4 d8 W3 S& Y3 z/ v
                       "GRID-SIZE-Y sliders, or decrease the "7 z3 C* @$ A4 A! X
                       "number of cars by lowering the NUMBER slider.\n"1 y( K1 f# w8 B: j
                       "The setup has stopped.")0 @& I" k6 [- r$ p3 a3 e+ X
    stop0 |) Y. u7 H6 ^9 H5 {- a
  ]% @4 o' t2 d# L/ w, P
, \& l* Q/ y5 T6 x
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
) i& H5 K$ |' M  crt num-cars
1 e* U5 C8 [* P0 D; G1 @& X5 u9 l  [
# J1 |9 \8 ?% a& \# A4 W    setup-cars
8 {* d# Z! _, h3 \. w3 t; ^. k/ m    set-car-color
! N" g  Q- I; F# C1 F    record-data' l/ N2 C' c* b" t
  ]
8 T' e2 ^2 I' V" }
# A# G5 E$ j! z7 p. b  ;; give the turtles an initial speed- E2 q! A3 d& M+ ]/ L9 K# u5 s! ^
  ask turtles [ set-car-speed ]( R1 ^  d* Y0 `8 u+ M1 k

; x/ f( `& J3 c4 ?" X- W  reset-ticks5 M5 s& r6 t! N5 M# C
end3 K7 _3 W+ N+ p/ z# [* }
0 U; n9 z+ m" ^, U! p7 ^3 w6 @
;; Initialize the global variables to appropriate values
' N2 ]( M! |7 X0 a3 }9 dto setup-globals+ @, m, i* J  W! J8 X
  set current-light nobody ;; just for now, since there are no lights yet/ n, {4 A- F2 ~3 D/ L
  set phase 0
! Z" L; t& j" M% K( w0 S  set num-cars-stopped 0; \2 h) M# W9 t7 C5 A( r
  set grid-x-inc world-width / grid-size-x2 ~% p# ?! c& J& h3 O6 c2 a
  set grid-y-inc world-height / grid-size-y
8 g& I+ ~! ~# @! ]* \
0 e! n! E# I- m9 v  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 w( C6 k: N5 }" i% D
  set acceleration 0.099* G8 N7 b& g0 @4 N0 \3 {' y
end
" |& i0 C( e! T
* D  k$ D- s' l;; Make the patches have appropriate colors, set up the roads and intersections agentsets,' _0 W7 [! n( O0 N
;; and initialize the traffic lights to one setting
  m3 _5 K/ k; T& R  Xto setup-patches$ T+ O, S8 C% H1 n+ F
  ;; initialize the patch-owned variables and color the patches to a base-color
, Y3 k% m; y) L! D: b& ^- K) g/ m  ask patches
6 a% R- O; Y( [$ ^4 X0 [  [
& V( [3 r. L& Q3 G# g% i8 Y    set intersection? false
2 s0 d! }: z% f$ o# m) W4 U$ z" X    set auto? false
. N+ O1 O. t* }, s" F. R    set green-light-up? true
( |( v4 e: L( v& I# U/ m$ `    set my-row -1- o; I! m) y& l3 x
    set my-column -1/ e7 o  j/ z+ d1 _3 [1 x% I
    set my-phase -1
+ E# C  W" U$ x$ k    set pcolor brown + 3# s' ~( D0 D* a* m
  ]2 I9 M: _% \7 ^& x/ @
6 P* ?; O$ a5 r2 Y, F
  ;; initialize the global variables that hold patch agentsets0 F! ]& J9 h3 |" G2 J9 Q8 g2 I4 p2 U
  set roads patches with( G  M) x/ _5 P- S) S8 l
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 P# D. c; {- H4 I/ F% K    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, R2 V3 Z; d; L; t' X  set intersections roads with
. a" s2 c8 j& g9 w: S8 u3 q* M8 V    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 ]# Q# i" Z4 ^    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ l4 B  ~, Y7 T0 b9 ^
( c; i. A9 C) Z: ^) h5 D3 a
  ask roads [ set pcolor white ]. b  y5 ~  @/ l2 }2 m/ y
    setup-intersections
3 p; y. q( n8 o- p/ Aend) _9 P+ y. s/ o0 ]8 K
其中定义道路的句子,如下所示,是什么意思啊?
1 m9 q5 X. g; @# [6 U set roads patches with
, G% X. I0 _8 @1 n    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" E3 [* G% L7 H, T5 S
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ W0 o! ]5 L0 S( f6 w: b* F
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, 2026-6-4 10:01 , Processed in 0.014030 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