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: 10504|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。+ K( S$ @, F" U# \* V; ~
netlogo自带的social science--traffic grid这一例子当中,
$ d! T  O2 D7 \globals6 Z6 p9 G+ ~/ h5 E
[
, o* P0 u7 I/ F2 Z% C" b  grid-x-inc               ;; the amount of patches in between two roads in the x direction
& ^( H8 \7 s: N, [  grid-y-inc               ;; the amount of patches in between two roads in the y direction+ ]0 O/ K6 Y2 W4 d4 S
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if7 q3 U$ ?- M& Z3 j/ d3 E* A2 o
                           ;; it is to accelerate or decelerate2 I) n2 t, A* a* ?) N3 i- ?
  phase                    ;; keeps track of the phase. b, n3 C+ t; Q+ a! y: u8 ^
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure& T  E0 G! X& q0 U% L
  current-light            ;; the currently selected light- _8 \7 i( r9 q9 j  M# ?

. d* }- S: j2 b1 U# c6 O6 X9 Q  ;; patch agentsets
& \. z8 C2 B$ N5 o- r8 n, F0 A  intersections ;; agentset containing the patches that are intersections
: Q* ^" X; Z& g: e% U" i  roads         ;; agentset containing the patches that are roads. L! a) O) ]# F0 v, c
]
$ f) N8 v1 k; }: B2 P9 B* X) A) I% D0 B& z) K, l; B
turtles-own% B. v3 K7 v2 D6 W/ g7 H
[8 T* q$ @4 `  U- q  N, x1 ]
  speed     ;; the speed of the turtle0 v; b- S# `% W
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right% l5 s; M+ A" c* A0 Q$ V) n
  wait-time ;; the amount of time since the last time a turtle has moved$ W' f$ x) f8 s3 ~7 o+ N
]4 D' C7 \1 b0 L$ r% u

, S8 L7 Y8 u; k: Epatches-own4 J+ t$ f+ w, }3 o5 [
[
! q; z0 p5 l$ p! k+ J  intersection?   ;; true if the patch is at the intersection of two roads
4 V5 I5 q' m' a  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
! k. G. u. q- K- Z' e+ a  d                  ;; false for a non-intersection patches.$ L  Y( g  v, v% i
  my-row          ;; the row of the intersection counting from the upper left corner of the
* Z( _7 _+ Q& C) q9 k0 U& R' G                  ;; world.  -1 for non-intersection patches.. K2 x, a2 L; K% {3 T7 }4 v( L- C, M
  my-column       ;; the column of the intersection counting from the upper left corner of the4 @0 y+ x7 n: O  ~
                  ;; world.  -1 for non-intersection patches.
, w6 n' }3 Z! P7 Z* Y  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.$ r" b0 H0 e+ D. R
  auto?           ;; whether or not this intersection will switch automatically.
+ C  f# P* a# D  m. o1 P* h! G                  ;; false for non-intersection patches.) R2 a1 Q0 B6 R- S6 m
]
; P5 {* @( N4 H  q; g3 D: f  i) R- A& k( C
, W5 b2 X8 F9 ^
;;;;;;;;;;;;;;;;;;;;;;! z' J1 r3 o- X0 m
;; Setup Procedures ;;2 i5 f0 W+ z' G3 s/ G, f8 X5 f
;;;;;;;;;;;;;;;;;;;;;;
* Q! T& B5 P- m, x" x8 u* ^, b! `4 @; r, {% q( r$ S, U' l# J  S
;; Initialize the display by giving the global and patch variables initial values.
6 N& x& X1 O3 T6 O9 z+ a2 q;; Create num-cars of turtles if there are enough road patches for one turtle to
2 g8 L: R8 K; o! X0 g' N;; be created per road patch. Set up the plots.) \2 Q; b( Z7 E! }# ]
to setup5 g( ]" s' F2 M7 w% i5 [$ E
  ca. M0 T* ]+ s' R2 z. f, @
  setup-globals
* r! l, Y" L3 n& r
& J$ y. f) v  v6 U! v4 }! a  z9 \4 @  ;; First we ask the patches to draw themselves and set up a few variables7 l$ d- ]* F5 a1 r
  setup-patches
& n3 W5 `; ^1 T  make-current one-of intersections- c& g! B) s( e! O
  label-current* c/ \" C' ~$ K8 L

+ r/ P! K6 o# ^  set-default-shape turtles "car"
( |/ }6 j# q% O* r3 h
& A$ Z1 K7 G. }" I' Y. X& J  if (num-cars > count roads); Y5 }, b+ }: G& L3 l
  [
9 _" V) K* v" J- F' d/ F    user-message (word "There are too many cars for the amount of "* }6 ~6 V: D" J6 Y; O& r, z
                       "road.  Either increase the amount of roads "* `- s- G5 k5 P2 y
                       "by increasing the GRID-SIZE-X or "$ ], n/ ~3 G" h
                       "GRID-SIZE-Y sliders, or decrease the "
0 |( }; V% y* `* t                       "number of cars by lowering the NUMBER slider.\n"
6 d9 L; [$ }$ O+ a. c4 z                       "The setup has stopped.")2 o8 J* a% e4 Q+ E. v$ D2 e( S7 q
    stop
9 _5 q4 l, n, P. `  ]& i+ @7 k" t9 {  e5 l
7 }, `  v, ~3 Y$ E+ j9 {2 q
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 d2 I' L+ D( N; s1 B  crt num-cars$ v4 y3 \8 V. E* Q, K
  [
, T0 B) s8 ]8 R: W7 K    setup-cars
( A6 D; g  m; X8 V: t* c    set-car-color. B! @* o. [0 v# T
    record-data
% k) F% d- T: }9 r9 G  ]  O9 E- D7 s- s* H. }; {

* W$ N7 b8 V2 o. z3 W2 j  ;; give the turtles an initial speed& i! W+ Q& n, G( ?. a3 K  I3 a
  ask turtles [ set-car-speed ]; q+ F9 |- M, D7 z# Y3 q2 E" d7 W

+ ?9 D. G4 U$ N8 Y- {  reset-ticks
) i1 _: o/ A. Dend, M) }2 x9 G, d+ b( {) J- k- z
+ w% j% m  g' [8 J
;; Initialize the global variables to appropriate values9 B' r1 M9 X9 b+ M: j) s
to setup-globals
" ^/ y0 o( ~: Y7 z7 A6 u% J  set current-light nobody ;; just for now, since there are no lights yet
+ f" I; \( h, W) G  set phase 0
; c& j1 x9 c3 e1 v( E  C  set num-cars-stopped 0
( e2 z! @: Q2 v2 @  set grid-x-inc world-width / grid-size-x
: u( |/ W$ I+ ^9 W0 W6 b& ]  set grid-y-inc world-height / grid-size-y. ]; O0 |1 u9 B6 g
! @! `6 E) `, K4 h, Z
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! g" w/ g6 _9 x2 d
  set acceleration 0.099
5 H' w# B7 a. I* _6 }& R! M, `end3 p9 l! ?" d! ?& [$ ~4 U) G

/ `8 u4 n9 n7 v* p6 `+ ?8 M;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. D8 X' c! q1 _
;; and initialize the traffic lights to one setting# s4 c$ N+ P8 K6 L" Y' R9 j$ f) _
to setup-patches, E. a8 t: a3 |8 C% K# r
  ;; initialize the patch-owned variables and color the patches to a base-color# V5 }  t* L4 H4 |7 W! d! f
  ask patches
( h6 T; B' \2 ?7 P  [# o' L; V. s; E" Q- t6 z5 I
    set intersection? false
. Z- h7 C; L8 r2 m; J' o    set auto? false& S9 L+ u& r5 j& i% X
    set green-light-up? true
& E0 U) k( _5 @# V  ]    set my-row -16 u3 e& u8 \; O: K% ^( H
    set my-column -1
/ T2 t. U' L) m( W2 Q- t1 W5 w1 |    set my-phase -1
1 t) k% u& h5 @# l" p# C' y    set pcolor brown + 3, |% G( H! V* h: \. N2 c- [& i
  ]/ t7 E! i2 K4 Z, H0 k: L! K, ~
* n- X. Y* N' K5 O" M6 T
  ;; initialize the global variables that hold patch agentsets
, [/ i. y9 C. m6 U/ P  set roads patches with
6 q5 ]. k% E4 g/ E0 J# B! |) t    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; M2 u5 t- c% W  _& t, K    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. i9 {$ Q1 b' ~* O. [
  set intersections roads with5 u2 L( G" ?6 `' q: A6 U
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 j6 M7 Q+ R0 x, l1 H0 Y# q
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: }2 D  f2 X0 q, D& \& N& m: g  @6 B# H( }' M' K
  ask roads [ set pcolor white ]' j1 F* z& C6 P9 G4 i2 l& [
    setup-intersections2 s; {* D( `+ [- t
end7 H6 C- L% e, E/ V
其中定义道路的句子,如下所示,是什么意思啊?' u" o3 W, k: g; @8 w
set roads patches with
( e. F% L3 b# |( C+ |    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. T( R, i# T9 P1 A% _/ z
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# K: r+ q/ s& L# F3 o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, 2026-6-10 05:32 , Processed in 0.017486 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