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: 9865|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。
3 N/ l( L3 ^3 f7 I! Anetlogo自带的social science--traffic grid这一例子当中,
9 T% }6 j1 [1 h1 aglobals$ O9 e, ]! g( C& K% }
[! _) m. r, N- B0 V7 v
  grid-x-inc               ;; the amount of patches in between two roads in the x direction! R( j: _# Y2 U- {& C  v! a& |
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
2 R2 U4 U& h; j, j  k  acceleration             ;; the constant that controls how much a car speeds up or slows down by if& T4 J) Z* Q+ S8 t  ?
                           ;; it is to accelerate or decelerate! f8 v) w" V0 f& }$ s1 V  r) g% K
  phase                    ;; keeps track of the phase
* D$ j6 J- z) m/ H; p$ x5 m! [  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure8 X! u8 ^# d& P5 G1 ]
  current-light            ;; the currently selected light8 M2 g- @( Q, c, i
# J$ G" B8 W- y3 O: {$ y7 [7 f% {
  ;; patch agentsets+ U/ G# q) y+ b
  intersections ;; agentset containing the patches that are intersections5 F" V1 @: i0 n( x7 _4 Y# y& ~
  roads         ;; agentset containing the patches that are roads
& e6 P& ^' ]& S4 i]
5 _  _& V5 y4 O, j+ `5 x5 o- R7 ?1 m- |- k2 E
turtles-own
3 q: ?) z$ R9 P[( ~# }- l% C2 Z
  speed     ;; the speed of the turtle
  L* `" b: T% N) x  up-car?   ;; true if the turtle moves downwards and false if it moves to the right# U1 O0 n% U- V* ^3 K
  wait-time ;; the amount of time since the last time a turtle has moved* f8 D7 j6 X8 E) m) j
]5 n2 m! |; T8 c+ n6 l( O
0 A. d1 @# ?: b- [5 G: q
patches-own
# ^/ c3 P$ t) Q% y( K) t: k7 y[
) ^+ q/ r: X5 H. h1 S/ P1 [  intersection?   ;; true if the patch is at the intersection of two roads
- q$ c0 J; T! l' j% ?) W; Z. M  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
* Y+ s9 p4 ?1 m5 p4 z                  ;; false for a non-intersection patches.
$ M7 l# n7 ]+ w" W6 r6 C' e, l  my-row          ;; the row of the intersection counting from the upper left corner of the! u; u4 Z5 {/ L) e
                  ;; world.  -1 for non-intersection patches.
. `7 i' D6 I# _( e- G( e  my-column       ;; the column of the intersection counting from the upper left corner of the( N" e0 M( K9 X; \# ~2 g2 B% v
                  ;; world.  -1 for non-intersection patches.
* X. H4 x" o9 x; Y0 x  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches./ K& C: n2 d) J& N& p
  auto?           ;; whether or not this intersection will switch automatically.) K& B5 t0 H: j
                  ;; false for non-intersection patches.
) a, s, A" T' s2 T]6 j, P6 `3 F: d3 P0 @5 X: D. m

% w8 b9 r+ j' u7 |7 ~  u- L
6 o, f- }% `* j: P" R$ o. X5 l;;;;;;;;;;;;;;;;;;;;;;
: ]+ ~  R; }# f* l% I) M;; Setup Procedures ;;
8 c8 i2 m7 I/ }) h' ]1 }  K;;;;;;;;;;;;;;;;;;;;;;
7 f' H, |2 C3 g* w2 {8 H( e4 |. o. _8 y( ^7 W* T5 o  ~: p
;; Initialize the display by giving the global and patch variables initial values.5 a3 y' H; B9 d7 X0 _1 X6 a) H
;; Create num-cars of turtles if there are enough road patches for one turtle to
$ s. v/ y' Q4 ^7 v3 _;; be created per road patch. Set up the plots./ B$ l5 }: f& ]: A
to setup
8 D% I, {, Z  c$ Q- b( I  ca# v, O( I- w* r! r! V. r/ c
  setup-globals
3 J: G4 u; y1 a, `3 v* T7 S) e
  ;; First we ask the patches to draw themselves and set up a few variables5 d# m  `, L' a" v6 M1 ^; D2 P1 K/ X
  setup-patches! C0 V! b& F, u9 r' E- I! n
  make-current one-of intersections
% a1 l& k, t0 ~6 s  W  label-current
  a- v1 ?+ T' h7 `. Q, A7 l0 U  `9 N
4 o+ [* t* k  R0 x  set-default-shape turtles "car"
( m/ l8 S2 ], \. L  `, s8 S6 z) C) m
  if (num-cars > count roads)) {4 z% D$ V6 d# ^
  [
0 l9 ]8 d9 R# n! c3 v' [    user-message (word "There are too many cars for the amount of ". g" A6 y; X0 [) Z4 \
                       "road.  Either increase the amount of roads "
# _  L, U3 h7 t                       "by increasing the GRID-SIZE-X or "
7 M( W. s5 M% L2 j                       "GRID-SIZE-Y sliders, or decrease the "
' T2 p+ P) m  h( D" F                       "number of cars by lowering the NUMBER slider.\n"+ t2 @) N3 J. _" q: @7 {" V+ B# ^
                       "The setup has stopped.")
0 G, o# r- y7 P% K0 r- I" Z    stop. }$ _! V% Y! |6 b
  ]
/ D1 P: S( B" X1 l+ @1 ?7 I6 Y1 Q; Y1 e* s6 ~5 b
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 B: z5 C- ~* Z  crt num-cars
0 }  ]0 K" V" Q  [
* E, ~- q1 {9 G! c    setup-cars* C. {* O1 `1 M9 M- g1 x2 }$ y
    set-car-color* P( b" F- [$ v' o/ A0 q/ u, ~
    record-data
/ m* M0 d- u3 T( }* o6 R; a8 E  ]
" D0 ?  u% G1 O. h: j, H
5 j' b$ f) O, l3 Z. O( ~  ;; give the turtles an initial speed4 S3 o. u* C9 ?# \+ V# v; n
  ask turtles [ set-car-speed ]4 ^# q6 R" s5 u3 {! d

6 a1 e  P: A- F3 h) O- H( l  reset-ticks0 p( C! ?: B2 }
end
  a7 R6 y- y+ f3 p
( C! L3 J0 `/ ^8 D* ^  s;; Initialize the global variables to appropriate values. x9 K1 l7 ]" ^6 _8 X2 h7 n* }
to setup-globals
& R2 a8 ^$ x8 Z$ x  set current-light nobody ;; just for now, since there are no lights yet( E. y, E2 _% A% f
  set phase 0! f* m( s( I0 r
  set num-cars-stopped 0
0 n' `6 p; Y) F5 y  set grid-x-inc world-width / grid-size-x9 e, p/ v" `, T5 l' E
  set grid-y-inc world-height / grid-size-y
' @; z' K" _# ]6 a
% O4 I. e1 P" T  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 I- |% ]( M3 b  set acceleration 0.099: Z1 |" m, y# @, k- F0 r" p
end, F. o/ b% o/ M* n& Q# x; l9 m

* ?) V& S' k$ o$ l;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* x- X* k" T$ L* `7 x& z* O% M;; and initialize the traffic lights to one setting+ F3 u8 x. ?6 r+ B
to setup-patches
7 f5 t1 g- P4 ^1 p  ;; initialize the patch-owned variables and color the patches to a base-color
! c% K# `: Y3 l" y- i- A/ g  ask patches
& V7 s4 i3 v' j8 I  [
1 s: A! I9 Q( g8 T0 O. t    set intersection? false; _- N, u4 u0 a* k+ o
    set auto? false" w0 U! t9 T' j
    set green-light-up? true
9 |6 U/ W! Z/ [    set my-row -1
& T! o9 `) o+ ~( z' Y    set my-column -1; g$ @! ^" D1 K% a0 l5 c7 ?" y
    set my-phase -1/ Y0 `: z7 \+ I6 E
    set pcolor brown + 30 F$ F$ t! ]$ D" g7 h2 h7 A' T
  ]. W/ T4 X& D' O0 V) s+ x) |: S, M1 q

( p$ ]- Y) I- A* S  ;; initialize the global variables that hold patch agentsets
- t0 V1 B: H" q, z; h; a  set roads patches with
6 _$ P' @5 a! T2 M1 O    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& K2 i  ?& Q3 K( c) ]
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 y$ g* p' O( _* a7 E" i  set intersections roads with% f4 S/ M6 x6 r' j, Z
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% R. k2 E1 a& V' O. O; g/ j    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 G8 h2 o7 M; {" F
1 N: R) c8 Z; C+ s5 N
  ask roads [ set pcolor white ]
& l4 c$ L% y8 g' d0 T4 Y4 {    setup-intersections- g6 }  [5 Y5 o4 {. w
end
; k2 s2 f, ]7 P) x9 s其中定义道路的句子,如下所示,是什么意思啊?: w% S' I) w; h# C0 U  I0 K
set roads patches with6 A, x. n8 p8 |2 T# }" T
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 q; X0 Y( Y. W5 x4 Y$ X
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* N' J& b% `5 x, A0 \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, 2026-5-4 03:18 , Processed in 0.020650 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