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: 8715|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。$ @- X6 f6 c* ~9 K8 @5 N8 n* b: f
netlogo自带的social science--traffic grid这一例子当中,
% w4 ?3 E' K- d2 [! I+ s& uglobals
/ t3 L& r) T6 D' ]; w, \3 S[- c, H8 K: ]$ d" B( f
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
3 p- m( a5 v5 l5 |% ^+ i! ]  grid-y-inc               ;; the amount of patches in between two roads in the y direction' Z/ P1 I, {# q! l  z, K. N9 [
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if" y  r. o. h0 r5 z5 C8 u2 `9 w
                           ;; it is to accelerate or decelerate" b. s) x- e5 F% b6 C$ I
  phase                    ;; keeps track of the phase
4 D3 u' e- ^4 r; Z. R* t  B. d  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure+ x  ~0 v0 e3 U8 P4 A, a9 G) s
  current-light            ;; the currently selected light: p" S$ i' t  R1 g( j  |
1 T8 I% s: N1 U9 o6 v9 Y) `4 U
  ;; patch agentsets
. ]4 Z% \0 o  |# ~  intersections ;; agentset containing the patches that are intersections
- h5 [( x- r( i2 {& n$ J. a  roads         ;; agentset containing the patches that are roads
+ E2 [; I7 P2 z& q, ~9 |]- T7 X; t2 @5 }, a8 X0 F
5 `  A; S3 c- M8 N* _( I; `
turtles-own! P0 l1 p% h# P0 J
[
' s1 C+ e+ z- _% U4 P& o  speed     ;; the speed of the turtle( d2 B: |+ p; n/ r7 j! {
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
' V& B5 l! W: _7 j/ Q3 f6 k  wait-time ;; the amount of time since the last time a turtle has moved
% e0 X. V- e- L/ m0 A( x]
) P; P2 c: P# f. D% k! b" u& }7 V* N+ I7 c" _! U7 C2 Z! I( Y
patches-own
8 I/ k" r7 R" }* x9 n[
8 h) o* Z% A0 c8 |  intersection?   ;; true if the patch is at the intersection of two roads$ r2 o' R, \: W) M3 }
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
. F3 j6 o  [1 `8 f4 ?  D) p! r* C3 d                  ;; false for a non-intersection patches.$ W0 a* M* r( g" p3 X1 _/ X
  my-row          ;; the row of the intersection counting from the upper left corner of the* \% M/ k6 s! _- F+ \- o! s
                  ;; world.  -1 for non-intersection patches.
4 o( K+ `$ U, C# N5 @; D  my-column       ;; the column of the intersection counting from the upper left corner of the3 _5 D% k( Q9 I. M
                  ;; world.  -1 for non-intersection patches.7 S; s& C9 A5 Q+ P$ G8 I$ q
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
  d7 O4 W% z1 v2 u  auto?           ;; whether or not this intersection will switch automatically.
/ `3 i, c! C! r5 L                  ;; false for non-intersection patches.2 @# ?8 D/ h  y& h% C
]
/ [2 b3 {5 H8 i: |; z; {# a! [4 Y2 y/ Y- s3 K3 |$ z

, x" K" R7 D  ~- F9 C( o;;;;;;;;;;;;;;;;;;;;;;
; d4 _3 s! W: s( p4 o* A. Y( X% ?/ S;; Setup Procedures ;;
( |6 i! M2 O! b$ Q1 Q& {;;;;;;;;;;;;;;;;;;;;;;
/ g2 `1 x2 s* S1 Q5 F5 f4 f0 g
* s8 j0 V7 J' L+ w;; Initialize the display by giving the global and patch variables initial values.
: R+ Q8 j: V# `- U$ j;; Create num-cars of turtles if there are enough road patches for one turtle to
$ t6 m; K: F( ?) A;; be created per road patch. Set up the plots.. d0 F8 @" g- `  \* b
to setup0 j) z; i* W6 J; m
  ca
  F" a8 \; z4 Q, m' G$ {9 B; Y  B8 }9 F  setup-globals
* G4 ?4 x+ A2 R8 s
+ y8 q6 g6 F6 s5 d, Q  ;; First we ask the patches to draw themselves and set up a few variables+ C2 f; E$ H2 y: t8 N
  setup-patches: j9 S, H" N* A! X' I1 o$ @
  make-current one-of intersections
5 }* {3 h6 [. t. v+ w+ `1 T3 `  label-current1 C- f, i$ b, ^& u! i7 B
3 _3 Q/ v3 d7 Q' w4 _7 i* O
  set-default-shape turtles "car"
: w/ n! ]+ G  R8 i9 t2 o! V9 {# U& R' t% F
  if (num-cars > count roads)
# j# Y1 L" l9 l- B9 r# j  [
9 N2 o  \, }5 _    user-message (word "There are too many cars for the amount of "! k2 l, k- w3 H! s4 O1 D& u
                       "road.  Either increase the amount of roads "( X6 X& Q& s  n" j; m7 P; C% W2 C
                       "by increasing the GRID-SIZE-X or "% {! s: o' V/ R9 R  a- R, r
                       "GRID-SIZE-Y sliders, or decrease the "
: U* V. T6 {/ {% d                       "number of cars by lowering the NUMBER slider.\n"
2 I. t) o' k  ?. b' b                       "The setup has stopped."). Y9 X- g/ L; j6 F: M
    stop
, o7 H9 V9 _# z; f$ Q  ]
- B5 J. j9 Y9 s4 k4 a4 y' q
- d/ c0 B) v8 t  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) m/ M9 p9 y  r
  crt num-cars9 Q* l- k8 k) z
  [/ ]2 q1 p# c3 d5 i
    setup-cars
4 r  I8 o0 m$ F2 ]- {4 R, g8 q    set-car-color
2 U% E8 F6 R! \  C* |    record-data5 p4 s0 B- c$ Y0 o
  ]: t7 G8 `' t. a0 X! ?, M. r2 `' d& t
$ E1 G- o& _1 n# R! {+ a
  ;; give the turtles an initial speed$ O7 l9 @) z6 V; H# O% u; U
  ask turtles [ set-car-speed ]
. s: }  M, \, z$ A* U( V6 T" G0 V6 \+ Q; g6 s
  reset-ticks6 r7 W" t+ B+ f( o! E
end
- b( W2 d/ K6 c7 v9 p: o1 Y/ \2 b% |9 Z8 m6 Y
;; Initialize the global variables to appropriate values
; I4 v% E: w4 e1 j& F( Kto setup-globals4 o/ g* F) s) H" r
  set current-light nobody ;; just for now, since there are no lights yet! s* V# @- c4 u
  set phase 0
" I/ X% l; E1 t, T7 V2 Q" z5 O( ^  set num-cars-stopped 06 y6 c6 ^7 L% q
  set grid-x-inc world-width / grid-size-x( Z; v- b+ ]( _& J* ]
  set grid-y-inc world-height / grid-size-y
/ O# D3 A1 [0 u7 Y* q" @$ F, r/ O# V! y7 O
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% ~4 P5 D, T( J7 \& y" Z  set acceleration 0.099( K/ R: A. ]7 R1 e2 n  ]
end6 E1 g8 Q. u" ^4 S$ ]% q4 \
1 }4 M/ K2 a6 y6 U) W
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 U, w2 v' Z7 m) j& U;; and initialize the traffic lights to one setting
8 J0 f; k% Q2 g: n4 w7 b# Lto setup-patches
5 J  n' O0 R; @  y, R  ;; initialize the patch-owned variables and color the patches to a base-color
& ?2 X, F1 F6 V9 d  ask patches. k* V% m. V. d
  [$ \6 X2 I/ V* g) g/ B
    set intersection? false* s8 t2 V' H4 {& e7 Y
    set auto? false: `" r$ _- l3 q$ N
    set green-light-up? true
0 P$ K% s$ ^2 s, z7 N    set my-row -11 n6 ~4 K. c2 H: {% i
    set my-column -1
  R- W$ O+ d4 |1 J3 Q0 b$ h. a    set my-phase -1, o) _# |6 U% `  e2 D5 x
    set pcolor brown + 35 w& B, C$ T* J. `1 t) o0 _
  ]
' F, q0 Z5 K, x
8 h1 T- D$ o" h8 ]  ;; initialize the global variables that hold patch agentsets! |# s. ]5 P% Z: P! @
  set roads patches with) ~; C/ G, K: {% X; U' X9 x
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- v4 M8 m$ ^/ S; c: E6 D$ B
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# n# b1 Z5 w; {* }
  set intersections roads with
  a! r5 E# p1 e! L) ^$ R    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( d  j4 T. H+ s1 F. h. k  v
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' x0 m3 @; o; N8 f7 t# S' x* s$ M4 @, R: R8 f9 _
  ask roads [ set pcolor white ]4 K  x, h: s. \# X$ l
    setup-intersections
9 k% n, a( E4 I' Fend
8 Y" ]+ {7 @! M, _* }其中定义道路的句子,如下所示,是什么意思啊?
( i7 U1 w) G: U5 j% F set roads patches with
4 a$ [: m# `  z9 r    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* A/ R  g6 K( o
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& O( R! r/ O% ?* P) Q3 H' y" z- }
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, 2026-3-6 03:48 , Processed in 0.013613 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