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: 9727|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。6 F8 l2 B- }' T& t5 i
netlogo自带的social science--traffic grid这一例子当中,
7 E+ s4 Z8 {- ^( \- Z& G  A0 G+ Tglobals
7 Z1 @" O2 T$ M% i' [9 l[0 X, _% ?, w  ]$ c: Z
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
" W  n, g& K* J5 J! S  grid-y-inc               ;; the amount of patches in between two roads in the y direction
& b4 E- j4 I1 N- ?- d  acceleration             ;; the constant that controls how much a car speeds up or slows down by if- c# G: J9 l6 ]3 ^) M1 }& N2 |
                           ;; it is to accelerate or decelerate' B4 J( I$ Y6 m, M. w" d/ B
  phase                    ;; keeps track of the phase
0 c# Y  n+ d0 s9 R, r6 l1 C6 g4 z1 F  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure; J1 @( s/ \* E/ ]% _
  current-light            ;; the currently selected light
$ b) k8 W3 k. C* e& w2 C5 H+ j5 |+ @' _0 Z; s! O8 W: |
  ;; patch agentsets; f( m% k) e4 ~6 D
  intersections ;; agentset containing the patches that are intersections
4 w0 v4 i8 h# V" U1 z' X# H  roads         ;; agentset containing the patches that are roads
- s/ N9 f' k! T]- O) X2 ]; \* W5 w- o' [5 P1 q/ {9 N

- J/ E8 g3 ?5 xturtles-own0 o! l7 b' V, D
[* M$ z. }% u0 g1 ?' U# r9 X
  speed     ;; the speed of the turtle- V3 c! v' M4 d; L
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
) J3 R8 t( N9 m  wait-time ;; the amount of time since the last time a turtle has moved4 U( Z6 g# ~! r! M1 t- G  f
]8 Y5 B& B* A9 j8 s1 k5 u

, q! F0 K) P  e- o& [, lpatches-own" O- @- m( \; _- G1 V7 |
[4 s2 r$ n) L5 ]2 \& G9 o/ I
  intersection?   ;; true if the patch is at the intersection of two roads
4 o, B! _7 m% ?0 t# Y6 u2 K7 f( `  green-light-up? ;; true if the green light is above the intersection.  otherwise, false., b# n7 E$ G9 h% i+ c. T9 a/ m) ^+ d3 j
                  ;; false for a non-intersection patches.. Y2 B% }$ j1 \% o" Z
  my-row          ;; the row of the intersection counting from the upper left corner of the
0 t2 `; Y% X! Q: [9 f                  ;; world.  -1 for non-intersection patches.
( s, Z* L# F' Z# s  my-column       ;; the column of the intersection counting from the upper left corner of the% b/ u4 L/ Y# k) @9 E
                  ;; world.  -1 for non-intersection patches., k' {7 l1 N/ ^" E. e2 O# o( J- ?
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.6 d5 s1 x, M# Q1 E/ A1 g' s; F$ o
  auto?           ;; whether or not this intersection will switch automatically./ c( t" E* a  e4 [; d
                  ;; false for non-intersection patches.
: q: H: z7 ~5 K. r7 {]3 z& H& M  R+ ~: t/ J* p7 B

- C  p6 B4 h7 y" t, b$ p1 S+ P0 v9 x6 n% B+ D
;;;;;;;;;;;;;;;;;;;;;;; B; v7 w: U% l& ?$ F
;; Setup Procedures ;;
) a0 V9 u! g- z: s) c. \* C;;;;;;;;;;;;;;;;;;;;;;
0 g# J; b8 O; A9 I" z) x
) B0 |8 k& b7 u! j% H;; Initialize the display by giving the global and patch variables initial values.
# C: y/ y7 ?3 H3 P" d- e2 u% ]  W;; Create num-cars of turtles if there are enough road patches for one turtle to& G3 L6 d* i1 m$ Z
;; be created per road patch. Set up the plots.$ K5 ?. g+ g. `) F
to setup
" Z" b8 o' ]3 A# r6 @  ca
- z% K! f* W& O) e  setup-globals6 g# K% e3 ?( g; |+ H8 v
6 h2 B" Q! d% `& m( V
  ;; First we ask the patches to draw themselves and set up a few variables
8 ^2 @# h$ F" n$ Y" w: F! a" q' ]  setup-patches% c0 }. K" w* C1 r; g: U
  make-current one-of intersections( d( \% r* n$ l; a
  label-current- j* f0 }) ], o- p
. A, Z8 G7 A: I2 _" R2 p! b
  set-default-shape turtles "car"" r" P  l( X1 F% u, H
' L5 j( r2 F- Y; g
  if (num-cars > count roads)
, _' r" }* Z% X; E9 P. F& [  [/ b2 }/ K2 V8 ?5 l" K, k2 s
    user-message (word "There are too many cars for the amount of "
3 A+ i% I; R1 x" v/ F( K$ v                       "road.  Either increase the amount of roads "
- z' v2 l# t: n! m3 I% M7 ^- T) ]$ L8 ]2 h                       "by increasing the GRID-SIZE-X or "
/ `, c. Y) Z6 L( v6 o                       "GRID-SIZE-Y sliders, or decrease the "
: N0 R+ i2 Y1 l5 {8 L/ }8 Y, a% Z                       "number of cars by lowering the NUMBER slider.\n"
% G* x  l; P. @                       "The setup has stopped.")" ]  i; ]* V4 Y9 i! L$ z- k$ h
    stop
" l( l- K, f) V$ l" j  ]
* L- r9 K1 {8 k! a
& i8 b' Y9 r/ M. G7 y  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# C' w8 `( N2 F) `/ I  crt num-cars. {8 D" }) m+ Q3 H
  [8 L: {3 x4 f4 s4 l; L7 R
    setup-cars' ]! D; y6 b! j: N( {
    set-car-color
. l; I$ m- M% i1 i6 i    record-data
6 d6 z  s  {6 l  h; X9 {) Q  ]( V! I+ ?( E! X8 `* u  O& B& Y
, q7 a8 z+ ?6 ?
  ;; give the turtles an initial speed
; _! P0 l9 p3 B- c* e2 R) {, K  ask turtles [ set-car-speed ]5 R* I# W, Z) @6 J) ]9 Y

" Q1 [; d# ~! M) W  reset-ticks( @- @2 l# S# V+ k
end; ?" V7 w7 \/ y, ]2 _

' c; q6 Q. a( P2 }2 E- L" J$ U;; Initialize the global variables to appropriate values
& k6 i) X) e: ]8 Y5 |( l8 R; \2 Nto setup-globals& t0 m2 X% ~! M" K6 n! O# n4 M" R
  set current-light nobody ;; just for now, since there are no lights yet6 ]& O9 c) X! l- e6 i9 N0 O6 n+ ]
  set phase 0
" v5 t: `" Q! y3 g2 o! {1 K  set num-cars-stopped 0
4 @* Y- \3 K, }' t1 N  b0 ?  set grid-x-inc world-width / grid-size-x' s8 m) }8 k' B4 t$ X- o% i( B& ?
  set grid-y-inc world-height / grid-size-y
$ {, c) F& a& S6 J, w
: E/ E5 w$ |* V7 F0 Y6 a  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) T- I, [" c+ y  set acceleration 0.0996 I8 x- I# b7 y
end
; O/ q9 C4 }* D  `  r1 m, j) |
1 k0 {. m6 O; M* e- v/ O;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ K: F" o" o7 Q# I
;; and initialize the traffic lights to one setting
# P2 N* s' x5 {6 S  M; Mto setup-patches
/ i6 r  M, n% W8 D# P- ^/ D  ;; initialize the patch-owned variables and color the patches to a base-color5 [/ t' |2 |. K: Y5 M7 ]
  ask patches
6 V- r0 L) l9 G/ T  W  [, q; r- G/ |5 e' }3 f
    set intersection? false
! D& G2 d  q; \    set auto? false" K! J, @) `5 Y
    set green-light-up? true) C5 X; x9 G3 `  ~6 W4 ]
    set my-row -1* L6 x8 C% a: s3 b' E# K
    set my-column -13 _- M6 I8 y+ z2 n( C6 p7 |
    set my-phase -1
  k: m$ q2 d% @# Y; P' g: x! K    set pcolor brown + 3  o) r* ?. I& h  Q0 u
  ]
. t$ d& V0 P; _$ a  G5 H* U, }3 b; L0 l" m3 t% @" t) W' n
  ;; initialize the global variables that hold patch agentsets
! x& R' Q6 A* I3 t  set roads patches with
6 u$ V: g# {  H3 G- l, k: \    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) f/ O9 b0 A) _, ^, w3 O
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 h! [5 Y$ Y% N: R5 I% ]3 K  set intersections roads with
  m' ^! B0 E# V: i    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 O* h+ R: |; ]  p5 f    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 i' W2 K8 B. }" T* N8 Z
2 }0 Y; ?8 L3 \  C& y  ask roads [ set pcolor white ]
  f  }2 L5 D# C- o8 r8 G    setup-intersections; G+ X" G9 U; j- I, L$ s
end
2 G& D8 W% [' q6 |其中定义道路的句子,如下所示,是什么意思啊?
0 M: i) v# n" { set roads patches with; h$ W: W. s4 h7 ^* M9 h8 t9 N1 r
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 l6 U6 p' d8 u, G( ~" x
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 z. W! p9 \$ O, Y; }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, 2026-4-28 13:08 , Processed in 0.016344 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