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: 10625|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。; _" x3 S+ d  c" U* a4 h  D
netlogo自带的social science--traffic grid这一例子当中,- V" g0 |7 x% l! x6 }' h
globals; N' I* u, e! b' |  y. Y# w2 p  ]
[
2 p- ^) E7 [- ]8 Q; B2 p8 m  grid-x-inc               ;; the amount of patches in between two roads in the x direction: |$ {2 P9 N: U9 x+ `
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
* ]% `9 L% d- n6 N. H7 f. c  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
  J  ^$ c3 o' j                           ;; it is to accelerate or decelerate* I6 E- I" ?6 K9 N
  phase                    ;; keeps track of the phase8 y, {* `9 \* `0 U. v9 R
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
7 w5 U3 `) G! @) p6 e  current-light            ;; the currently selected light* m0 U8 p9 p) m6 d# n
/ u3 M. m7 a" [" a3 k; _9 W/ E0 k
  ;; patch agentsets) V% N, @0 h, o
  intersections ;; agentset containing the patches that are intersections
0 q* r* s7 G/ o  P3 h0 P% A' o  roads         ;; agentset containing the patches that are roads
7 q" I% }0 {% U( ~# v9 q$ X) u( L]
6 z4 ~+ i6 Z: ^; T+ P( J$ l: w3 U' q. Q2 O- q+ R' e* k- S
turtles-own
5 c6 U& x9 M1 c5 u' i6 T& q[  w) u# P+ Q) j; t' l% z) H2 {7 M
  speed     ;; the speed of the turtle
, S# y5 l! C! H0 B' P  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
& |0 ?6 p# U1 ^" o  wait-time ;; the amount of time since the last time a turtle has moved4 _: e1 T" o; z; _) w9 u( z
]
+ U1 L. _- |& Q/ z7 F
3 P' i' L' b7 n3 v7 q1 spatches-own* q+ z' R" H2 w0 ~
[# a. @6 D3 ?. A8 e
  intersection?   ;; true if the patch is at the intersection of two roads
, v, \; M& j( h# A  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
7 H  R, P( e  q) Y# E1 l+ [- c% T/ E                  ;; false for a non-intersection patches.! R8 X; |$ W) _# e8 z) e1 H
  my-row          ;; the row of the intersection counting from the upper left corner of the0 M0 A+ e! l9 d. i- [, {- H3 l! E
                  ;; world.  -1 for non-intersection patches.
4 e/ Q% X6 q- K0 b0 X  my-column       ;; the column of the intersection counting from the upper left corner of the
9 p( I. H  F$ B! b  g4 u  y7 a                  ;; world.  -1 for non-intersection patches.
; Q0 z3 y- J. j* y  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.& `" z) Y- h) o3 G
  auto?           ;; whether or not this intersection will switch automatically.' O, Y3 }/ D& i3 ]
                  ;; false for non-intersection patches.6 v* z4 l7 A# \! m' e8 D8 C, I
]
/ V: M0 y+ _4 X: g" k& g3 c
6 z( m) r4 r7 G4 V) J4 g! y
) v- f, ?. T! x3 s6 x1 A, Y$ N9 S+ b;;;;;;;;;;;;;;;;;;;;;;
( {1 u. l3 l& ?3 w;; Setup Procedures ;;
" I) t( m. d8 ~' l! O;;;;;;;;;;;;;;;;;;;;;;
# I; b) q4 l7 I3 f- o/ {
6 B' _7 d5 ^* V;; Initialize the display by giving the global and patch variables initial values.( j  ^7 ]( B* |( y
;; Create num-cars of turtles if there are enough road patches for one turtle to
0 _- ?) v0 u" @3 Z4 L0 ^;; be created per road patch. Set up the plots.
# H* c1 [0 y' i7 I6 |/ Ato setup3 h0 X& {9 v- ?. |4 U8 r* x, y8 B8 s
  ca. w( S4 y' ^6 h% V" z2 P* ~
  setup-globals& e1 m) F. j, g
: d' q3 u; c% Y8 H% ]6 ], M
  ;; First we ask the patches to draw themselves and set up a few variables
6 E0 Q7 T. i; V2 U' S0 J9 Z) ]/ i  setup-patches2 ]+ N3 ]- y) _0 A4 B. Q, ~
  make-current one-of intersections
1 h5 ^! y& z# a  label-current
2 o1 w' a  z. \
/ E7 V2 H* J+ w  set-default-shape turtles "car"5 {# c4 `, y* u1 S6 N% W) @

4 y1 a! C$ h! R( Y  if (num-cars > count roads)
* K; y5 t% w* A. o, ^& o  [
: e7 j" v, s8 t# D& k    user-message (word "There are too many cars for the amount of "
3 C4 ]7 f% s' f! x# B                       "road.  Either increase the amount of roads "
" P! \9 i( C3 y! F, s/ m                       "by increasing the GRID-SIZE-X or "
! X( z' ]. f% d/ j- n! f                       "GRID-SIZE-Y sliders, or decrease the "
1 R' v  D5 s( H                       "number of cars by lowering the NUMBER slider.\n"
2 g' C# s$ \) ^2 @# z% r                       "The setup has stopped."); i$ L0 u8 T" [  G
    stop
' A* k5 e. B8 N7 ?( T6 I  ]
3 D" N# j$ S1 C/ Z, v+ b" s% u# ?. N# N3 Z: Z) ~
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 D* R: J! t% O# @/ F  crt num-cars( W, d, M8 C; L
  [/ W; U( N4 }5 f8 t3 @1 g
    setup-cars
. c2 \: F0 f  e+ u& X' D    set-car-color
2 I- }, A/ B- w/ N1 ]    record-data
8 a/ s3 k, |. t- D  ]: R# N% e. n" h0 R) B

' a$ u6 V" {# }* A  ;; give the turtles an initial speed
" y6 F% H' h: ?  ask turtles [ set-car-speed ]: f6 _2 E" t2 n0 U9 S4 p( L

, q7 U# `# k9 Z  reset-ticks4 x, I& A* s0 V* H8 t$ _
end( P. I" Z6 }: q: j- j+ D

* ]& w- }4 ~( G5 q$ p: e* Z- W;; Initialize the global variables to appropriate values
# R+ S8 L$ |' {" v- `. Nto setup-globals* X  N7 r7 e+ ?2 z% o4 ^
  set current-light nobody ;; just for now, since there are no lights yet
7 v  A" [2 j. o7 y  W  set phase 0
8 U5 U! s. F4 E+ W: ^% b  set num-cars-stopped 0
' [- P( i8 g! X  l' c1 O  set grid-x-inc world-width / grid-size-x
/ e2 P5 T! L- t4 J0 g/ ?  set grid-y-inc world-height / grid-size-y
2 [% a6 N4 _0 P) w9 O6 f; X/ \- u
* Q& x+ b# C- d( f  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' }' R0 T( `, f; ^" S( b6 k
  set acceleration 0.099. ]- {3 o4 J, H4 J% e8 W. R* n
end
+ n$ M: B/ C2 \2 b, j+ l" j" U+ r9 o1 j! S) T" }. c6 B1 h
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,) V9 u; d/ O9 l! s
;; and initialize the traffic lights to one setting' M. k! d- p& w* m  Q$ C
to setup-patches
; g& G% W' K8 `' D  ;; initialize the patch-owned variables and color the patches to a base-color9 w; b' a" H" N6 [3 M; b
  ask patches6 p0 e" W% K6 Y& H
  [
; r5 d5 O! `: f7 P4 c3 I! r    set intersection? false
$ R$ Q) u: e# L- n9 M    set auto? false
- G: B7 _2 h$ v8 q# h    set green-light-up? true
; f# b$ c3 O3 I1 M" `    set my-row -1# {8 \6 y, z0 O8 G% I% ~: M% E
    set my-column -1* Y* t5 {, I0 h. _
    set my-phase -1# O4 [8 g; q6 s" U2 }
    set pcolor brown + 3
9 m& C2 b% ]9 E0 ]2 w, K& ~3 O  ]
# a3 P9 a7 k/ q! U/ R) a5 C8 C" h' s& r( y! i' |5 P# B
  ;; initialize the global variables that hold patch agentsets
/ F  ]8 J$ w0 }- Q$ l3 w1 e: P0 s  set roads patches with! S' V" j! g5 _) V+ f! ]
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 @4 h; k6 e$ A    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- _7 a& S2 Z" B8 Y9 Y
  set intersections roads with
0 }  @# b( ^4 l' A  @    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, x' H! U( M3 o/ c6 w: G$ ~# Q$ v1 W    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 L% Q  F% G' n/ g2 |; Z: g& a* t9 [6 r# Z& O
  ask roads [ set pcolor white ]
6 a1 h" A3 M5 Y4 }( R    setup-intersections2 V+ t% y* G" a  ]' |- _
end% y$ f  v& n& S, p
其中定义道路的句子,如下所示,是什么意思啊?% I( m3 ?+ S: Y4 l9 ^, }) Q  E) I
set roads patches with' `0 o6 T0 S, `$ }2 F7 f
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ L4 Z8 l0 p. u# w
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 B* z' h  |5 l& L+ e5 n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, 2026-6-16 21:53 , Processed in 0.012937 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