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: 10918|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 Y8 R+ l' d& d  L6 R% i; X; Inetlogo自带的social science--traffic grid这一例子当中,% M5 M* {  |3 r1 k# J
globals3 c7 B  ?6 ^+ F
[
) F+ p  w4 [3 Y* U9 |  E  J& ]  grid-x-inc               ;; the amount of patches in between two roads in the x direction% R/ g; F2 K' B" ?- k
  grid-y-inc               ;; the amount of patches in between two roads in the y direction; K, y. S6 Y! z7 `) a
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
8 D* c+ u+ B( C                           ;; it is to accelerate or decelerate
0 C9 }0 t9 j2 S5 f7 b0 J/ P  phase                    ;; keeps track of the phase: V( Z/ i/ N9 V+ z5 f
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
9 M& P+ E# D* C2 ~* @  current-light            ;; the currently selected light
" s* X+ }( ?9 N* ]3 l! a! z: X6 H, S% n& O
  ;; patch agentsets
; k* r1 l* H/ I! v; w$ m3 r( i  intersections ;; agentset containing the patches that are intersections  {$ v& m/ Z3 a8 I! l+ Y7 |3 ~
  roads         ;; agentset containing the patches that are roads
2 j) q2 f/ c2 h& l7 n, j]0 E7 E, h( k" _* q
# o7 u4 A; T- Q
turtles-own
- M7 i/ h4 h6 {2 K7 T; @% L2 j* `[
8 K- D9 r6 y3 J2 ~3 V( A4 P* X( M+ ^) B  speed     ;; the speed of the turtle8 i0 c* y; C1 T. [
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
: R) M! M, m0 V  wait-time ;; the amount of time since the last time a turtle has moved
5 M( Q7 q9 g, w]5 b& V2 O% \, J$ f' I
% e/ p8 W! `3 b$ a0 z
patches-own/ k( l' P) d- c; U0 F9 b
[  {1 G  F7 n' p3 x: p! f: |' e0 R+ y5 h
  intersection?   ;; true if the patch is at the intersection of two roads
0 a# E1 r4 v: C+ n: w% f  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
2 z# @% x, b) G. ?& B: b                  ;; false for a non-intersection patches.
% T3 @( O4 n9 \: G- T  my-row          ;; the row of the intersection counting from the upper left corner of the5 g7 T  U2 u) R) i3 o* U" T
                  ;; world.  -1 for non-intersection patches.1 w! k5 q- C& b  e. s
  my-column       ;; the column of the intersection counting from the upper left corner of the
* S/ @2 y# _% G6 g  F' y  d( }; A                  ;; world.  -1 for non-intersection patches.# b, R$ d: M0 \9 D
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.; |* w2 E' [2 Q* {$ `, V3 |9 u
  auto?           ;; whether or not this intersection will switch automatically.8 ^" d9 x1 t$ _+ u9 \/ T8 L; h
                  ;; false for non-intersection patches.4 h( E0 }* y0 P" n( G
]/ c( Y6 q# @3 {) ?* H2 C
5 Z" q8 w- |' |3 _. D0 x, W0 ]) ]

1 P8 ^: i, Y; z;;;;;;;;;;;;;;;;;;;;;;9 D! j* e; R0 H, z6 y7 \* @5 m% P# x
;; Setup Procedures ;;
* G" O" J% h1 \5 j: Y;;;;;;;;;;;;;;;;;;;;;;! p* C  V  B4 R; `4 `) ~
( i4 A# G* g' O1 f- E3 s' i
;; Initialize the display by giving the global and patch variables initial values.
$ A& A. L+ p2 @, r;; Create num-cars of turtles if there are enough road patches for one turtle to
# \3 C* q/ ~- L1 Y;; be created per road patch. Set up the plots.8 C4 V5 m# N& N
to setup
  u% _/ i% z% ~% R! M  ca
1 q+ \# E8 {! O6 ]* y  setup-globals
6 M3 @) A2 W% `" I2 b0 e" {" h
4 G2 e" h' ?0 c$ X# H+ t3 C) L  ;; First we ask the patches to draw themselves and set up a few variables
6 ]" m* }, ?4 p( T& h8 ?  setup-patches
0 Q/ W+ L' b- e- Z: `' I, \  make-current one-of intersections
% k* l1 m5 G5 [  label-current
0 e! e' Z% K& ^1 \  D8 I9 c# c, E2 N6 J
  set-default-shape turtles "car"
, E4 x5 J1 ?7 }8 u5 t" p( I) \5 C8 O% t; I7 s
  if (num-cars > count roads)
3 [& K9 Y% f) H- j4 p  [
; h3 Y5 f$ L0 s    user-message (word "There are too many cars for the amount of "
$ V# w5 t, \5 G! J6 x                       "road.  Either increase the amount of roads "
3 }* `/ Q) _2 ]& F# ?$ o; k; `1 Z                       "by increasing the GRID-SIZE-X or "! z/ }, B" M0 z- y# C2 v% J
                       "GRID-SIZE-Y sliders, or decrease the "" u' h3 M& B* k& G
                       "number of cars by lowering the NUMBER slider.\n"
# Q" y+ e) s9 h/ ^                       "The setup has stopped.")
8 Q( y* o$ l0 i- W8 Q4 `    stop
& p8 Z/ `( \1 F  ]
% a9 q1 S' s  U$ V, w' @
  s' X( H! w8 B2 J# `- o. g- u5 @, V  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
) D/ A# a) n( @( m/ s  crt num-cars2 c* p/ }+ }7 w
  [
7 P+ g+ [' E8 b, O- ~2 h$ O    setup-cars
" A4 x" V% I( j6 f    set-car-color
- I6 {) Q3 `1 g- g/ G9 z% W    record-data! Z& b/ ~+ d3 u
  ]5 d9 b, d4 o8 r6 s
& e7 ]: z2 h/ s: f
  ;; give the turtles an initial speed
. Y/ ?; T& \+ a. Z3 m' k8 U  ask turtles [ set-car-speed ]' F; |% ?/ q8 k( f
2 Q5 Q2 N: P" O  h, n* |  A
  reset-ticks. A; H* V+ ?) U, W- J
end+ D3 m5 a4 K- ~( P5 A
" X2 H9 Y5 d7 z- p
;; Initialize the global variables to appropriate values
# N/ j- T7 P. Z9 wto setup-globals" \& h, }, b, M! Y' @0 R
  set current-light nobody ;; just for now, since there are no lights yet+ |& b- `8 ~" ~6 {
  set phase 0. D$ B6 _4 }3 p1 G6 @4 `
  set num-cars-stopped 0
  [: R& j7 O: S/ X( Z' k( \  set grid-x-inc world-width / grid-size-x
0 ~; F3 I" v, q7 P  set grid-y-inc world-height / grid-size-y' k+ A/ ?$ ^$ Q0 B, F! R
3 k* V* F6 e. q' S. ]; \
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 `) I3 B1 w9 {4 I( f, ^% F  set acceleration 0.099
' T* b' n. ?" V. u2 w& F! cend
* W5 {" `$ {& Y4 l6 N3 P6 r' ~5 x* M1 a
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 ?, c- w1 E, C2 d9 j6 d- u;; and initialize the traffic lights to one setting7 p- V" v6 ~* B. l& I2 L
to setup-patches: R% d* u% O- a  m: h: ~
  ;; initialize the patch-owned variables and color the patches to a base-color
  V8 x. m1 \+ K, K8 b* F6 x  ask patches/ |8 M% U9 W& t: }
  [
( U7 P' Y2 \) R* l6 O    set intersection? false! V! k' C% I8 I
    set auto? false
& ~* c. k9 J6 K0 r    set green-light-up? true
; ]4 t1 ~/ i9 H0 E3 u    set my-row -1! c( P1 A$ L% B$ X; t) `
    set my-column -11 C' O7 ]  y3 P9 Q+ ~
    set my-phase -1
& b2 ?0 i: l# w2 O    set pcolor brown + 3
% u7 t6 s" d6 v/ E! k, p. I  ], G+ A! ^$ [8 p! B, v9 r; N( T

2 H4 j7 a6 p: R1 C5 {  ;; initialize the global variables that hold patch agentsets
  e7 D5 v' e6 ^/ Y$ O( S, ~  set roads patches with
  j5 E% u- y) A- o    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) B' c* W1 M8 B; |, k) r' N
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 ^% _+ i1 Y# y# o% O& C( h% f  set intersections roads with0 L0 S8 _5 e; c! Y: f8 e3 ~" a
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 x% i" H1 [# n" W1 ?* [; G    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 ~+ o1 Y: C/ ~0 j  i- D3 G5 ]5 x: S4 \! i7 r$ K6 `
  ask roads [ set pcolor white ]
5 n6 g; h8 I4 S6 m" k    setup-intersections, ^8 d9 r5 e0 F1 @# Q% R" u
end; h! k' h8 B/ }! |: [% G
其中定义道路的句子,如下所示,是什么意思啊?4 ~3 d- I3 q" I# y. r6 k9 z4 ^
set roads patches with  `: U8 v3 s, Q2 d* N
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 L. z0 g/ Q8 B8 N2 i    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 ~+ ~# S. }9 e/ [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, 2026-7-4 11:00 , Processed in 0.013440 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