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: 10482|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。
5 Z" t5 O' k7 B$ f' p1 j7 i. `. b; pnetlogo自带的social science--traffic grid这一例子当中,, w+ W7 r& x/ D/ l0 z  o% N
globals
$ i8 k2 U% I2 w1 e" c[! y3 V  Y* |& j3 R; ]& t9 f$ R
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
. p; h! c  P: H5 ]  grid-y-inc               ;; the amount of patches in between two roads in the y direction: P. D1 I" y* r! e% c6 k0 ~+ ]0 B4 I
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if' U+ o- {" ~3 f" k. w
                           ;; it is to accelerate or decelerate8 X' L6 Y# \+ B3 R$ N) r) W) v
  phase                    ;; keeps track of the phase" M) H4 T, @( g7 P
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
% f' u0 I+ Y$ v% D8 I  current-light            ;; the currently selected light
+ a9 _" n$ `- c: t3 f: R
% O0 n. c  l' D/ Y0 F  ;; patch agentsets
* g' U7 L7 ^% p$ a. G. W' K  intersections ;; agentset containing the patches that are intersections0 D$ o; H$ W* c  V6 c, I
  roads         ;; agentset containing the patches that are roads
$ s$ u$ R% ]$ U* w]& S- l# A7 c6 O0 D" _

8 H# b( V! m; r/ K1 Z* Y/ V: jturtles-own1 k& P9 a- a/ E0 j+ [
[
6 W% S: x# U0 f) L) T( k% i% E5 n6 x  speed     ;; the speed of the turtle9 u8 C7 X( a% \1 D
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right6 Q4 D! B; h! C+ y( \1 l9 ~# ?. [
  wait-time ;; the amount of time since the last time a turtle has moved" {. S+ n9 H0 x' F# e8 t
]
2 J; S& L7 e( |: F  }" F7 N6 d, o0 D# a# u+ ]- T) V
patches-own8 z/ U0 ^+ W/ m3 q5 D8 F) O
[, u0 P% K; ^; @4 J% }  o
  intersection?   ;; true if the patch is at the intersection of two roads
' d$ E* |& a. N! [# }  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
% n+ h4 p0 k+ c  f0 D                  ;; false for a non-intersection patches.
0 D% t; K4 |0 m0 F  T3 M: a: q  my-row          ;; the row of the intersection counting from the upper left corner of the( {3 a% H" H9 a
                  ;; world.  -1 for non-intersection patches.% w) e6 S, G2 }: A* x3 Y
  my-column       ;; the column of the intersection counting from the upper left corner of the
6 M6 m* d* P; `2 Q/ F4 @- g                  ;; world.  -1 for non-intersection patches.
4 y+ ~  o8 k6 H  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
. W. l- g* i1 ?! k5 W  auto?           ;; whether or not this intersection will switch automatically.4 h$ A+ F, E2 [" J- ]7 U- c
                  ;; false for non-intersection patches.. a# S) M2 \: f" R+ ?8 U
]
8 R& j; z" f9 m) L# j6 T; K2 u: A; U2 p4 F, u5 x
7 l4 |  z6 b" I. w/ R1 {2 b
;;;;;;;;;;;;;;;;;;;;;;9 w/ e1 I% n( `9 c
;; Setup Procedures ;;! H, c$ _* w$ ?+ D' P: C
;;;;;;;;;;;;;;;;;;;;;;
5 g/ d& _  w" I" Z) T. G; M$ l7 N. I% r% ^; D6 z# S! n9 q
;; Initialize the display by giving the global and patch variables initial values.
/ v5 b! [# b/ @* F8 r" O6 U- D; A;; Create num-cars of turtles if there are enough road patches for one turtle to
- A9 a$ U4 I. K6 O5 j, p" c;; be created per road patch. Set up the plots.
( b6 E, w. A' j7 @3 Hto setup3 ?) n9 T4 ]4 x8 ~5 E
  ca& Y8 A0 ~1 y1 V# q( D/ Y' @: v
  setup-globals
, ]- w/ t, [  B7 X/ n: d2 t$ W2 f1 e) g
  ;; First we ask the patches to draw themselves and set up a few variables
% C& b/ Z. e. F3 P' F  setup-patches$ r9 `" @1 ~, K6 O5 C
  make-current one-of intersections
, }+ X: N7 i! n1 _: M! T, _* t) {  label-current& x9 h% X( O6 J) H3 N- E: Y: ]
. v' N0 r* Y6 f* W+ |
  set-default-shape turtles "car"4 |, P/ z0 b2 u5 M- y

' }- q' V( ~! o2 ]! T, f0 {4 F  if (num-cars > count roads)
) ^2 W6 C2 j7 q/ L: C, J# T  [
7 R3 {' G' X/ b6 X- s+ P    user-message (word "There are too many cars for the amount of "" ]9 c5 P& K# S4 h
                       "road.  Either increase the amount of roads "
" q. `$ M+ U8 q# D% O                       "by increasing the GRID-SIZE-X or "7 K) }! H  a. O+ u
                       "GRID-SIZE-Y sliders, or decrease the "3 @& H  ^8 a& p2 V
                       "number of cars by lowering the NUMBER slider.\n": L, ?, K: P2 K) M
                       "The setup has stopped.")
0 O# G3 M" i7 ]8 [    stop8 x) ?' q% ~* s! E
  ]
' p( S$ Y- X$ x1 L& X9 G, c
9 }3 X% k( N, w- d% ^/ N9 Y  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 `8 G" j( z; P0 F* v
  crt num-cars
3 L% G* F5 `+ Q3 ?1 _- r: O  [3 p2 o/ I9 H/ W1 ]% l5 ?
    setup-cars
3 ~) K& A" i9 W' _    set-car-color! h0 z; e4 f) B! d$ m
    record-data* F7 o* {( C; [, j# e
  ]( i8 E" ?/ n! y% \7 p2 Y
' X3 v+ ]9 b' j/ X# U( L) y; B1 O6 E
  ;; give the turtles an initial speed& g- F# \+ ~$ [: g9 H9 k2 o
  ask turtles [ set-car-speed ]
# d) F, H3 N9 F1 K) m) w1 a5 P8 O, B
  reset-ticks( ]/ I) s4 l* v
end
' z) d) {2 n" U. [; C* X/ T3 G% \' H
;; Initialize the global variables to appropriate values* @! s3 Z  |" j$ E' h  j) X
to setup-globals( Z% P- ~% z0 x5 B8 d( y
  set current-light nobody ;; just for now, since there are no lights yet  W/ f" ]+ o. E
  set phase 0
' Y6 Z  L8 J6 I' ?2 l$ L& M  set num-cars-stopped 0- _6 L' O1 L: C  X
  set grid-x-inc world-width / grid-size-x
. ?4 u  H4 n) z& a  set grid-y-inc world-height / grid-size-y6 q' B6 u& u6 q

# u+ N3 b! [5 R5 U+ h  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 D: H  C- X* p) ]2 ?
  set acceleration 0.099. d/ G: T8 U% w/ L6 e
end
2 Q) Z3 c$ ~+ e! c7 I( h1 C3 ^
, F; n) o% s: G6 ^  c. B0 ?' y9 `;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% [4 a9 O1 w, [: C;; and initialize the traffic lights to one setting  j3 G) ?. z0 I' y6 o' \
to setup-patches* `, X) T) T; L- L9 u
  ;; initialize the patch-owned variables and color the patches to a base-color, X; f, H5 T$ u9 n& e2 Y
  ask patches
+ F+ I$ A; W% M9 D0 M  [
* `4 Y6 [7 y9 ^9 V    set intersection? false
. b$ g: d& D  H& h4 l. a7 d    set auto? false
# ?7 K' J3 E+ A5 d- H1 W- p5 H8 F    set green-light-up? true3 T! M% \# h% P$ F! ?  q
    set my-row -1
) ]( L0 j6 L8 m8 W+ Y( b% D    set my-column -1
2 S6 {# {9 Z6 ?* G/ `3 K    set my-phase -1
( C  T: \' Z5 H& V+ o! F    set pcolor brown + 3: F; B% n7 J. Q% V6 H% @$ N
  ]
( ~- d3 x" [0 M/ g' f$ w2 l% m+ X
# t+ d0 Z3 m0 B6 j, a  ;; initialize the global variables that hold patch agentsets" A" d) M6 Q! p9 f. s* ]6 U
  set roads patches with
+ z' P1 f- N% S& \; j! {    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! M4 V: d$ j, d% f1 V) H9 r# A    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 H3 p5 f7 h7 n. p5 ]
  set intersections roads with8 n  c: G5 P6 V
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% q6 @: N. O6 [$ h8 R7 H* g8 z
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ O2 X: ^0 v- `5 |( Z' z" K
* Z3 H: u% D7 v
  ask roads [ set pcolor white ]
) \" z; m# o# a    setup-intersections
+ ~4 D' ^- P, `+ T/ [2 aend, I4 k4 k" I0 Q: F" F) C- H$ w% w
其中定义道路的句子,如下所示,是什么意思啊?
" z# H" C* D4 a, w0 O set roads patches with+ o0 I" S" i; u* M! I
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 Y" Q5 x" B; G6 E
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) Y/ `0 P( 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, 2026-6-9 00:31 , Processed in 0.014963 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