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: 11566|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 S; i# p: A4 j. l  F# _7 D
netlogo自带的social science--traffic grid这一例子当中,) \, P; z2 W  ^1 C" e
globals
$ C& f+ ^3 W, \4 f- \/ T6 h& j[( A. b) J1 C1 N/ `
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
* o: d: N/ B. E  grid-y-inc               ;; the amount of patches in between two roads in the y direction
6 {; T/ g' r! z+ [9 k  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
* c5 h1 I8 Y" P                           ;; it is to accelerate or decelerate
4 F  F3 }1 g9 F5 E  phase                    ;; keeps track of the phase
% f& j* H! Q# y, @' ^6 |  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
8 I- p2 [7 W& b0 G. f  current-light            ;; the currently selected light
& z( U2 u0 V; p% M
1 |0 e& i$ r& R1 D5 J4 @  ;; patch agentsets
, l! G' W5 `- v$ V  intersections ;; agentset containing the patches that are intersections
2 F# D" C: Z5 `# q/ `. }  roads         ;; agentset containing the patches that are roads) j, f: ?8 y  D. V3 E
]; h" D+ Y! s% j( ]
& ^% k; `  A3 y& Y3 m& E
turtles-own
# {/ F& q- Y* V; Y- J' J[
& F9 o4 w! T6 C; S# t1 H0 D  speed     ;; the speed of the turtle* C$ A0 M+ D5 m5 D
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right- P2 ^4 v1 B7 d0 }4 X
  wait-time ;; the amount of time since the last time a turtle has moved  p; u! o0 h# T8 G) I% ~
]
8 {9 ]& w6 \: s( {+ C6 E+ m- J0 ]/ [8 f  ]' ^! m
patches-own
. K) d: l! Y  G4 F3 f" c1 V7 c) g[
1 H, r' P' M) q5 d, ~  intersection?   ;; true if the patch is at the intersection of two roads: b# z* v) _: v; f' |
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.& ]5 E2 s4 L: |! J0 n3 Z
                  ;; false for a non-intersection patches.
9 t& h8 y' k) Q  my-row          ;; the row of the intersection counting from the upper left corner of the. g3 b, C$ d, n3 ~2 k9 f5 y
                  ;; world.  -1 for non-intersection patches.
  e/ p2 _4 s/ y, L  f  my-column       ;; the column of the intersection counting from the upper left corner of the4 P' h0 H) r' U0 e4 v3 |" }1 d7 p
                  ;; world.  -1 for non-intersection patches.1 h+ w) f" o7 o! P# c
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
0 f% B5 M# i2 I9 ]8 Z0 \  auto?           ;; whether or not this intersection will switch automatically.- |! c: K' y0 ~2 O. h2 c5 J6 k
                  ;; false for non-intersection patches.
) U0 u" {$ y9 @6 ^" @6 L]
+ ?3 D) [1 {! \6 q
8 i; [$ E7 g* w) \! [  n% p
) H: s3 z: B# z$ O, J4 l, c;;;;;;;;;;;;;;;;;;;;;;
7 B! x, ^- v9 l5 N2 `; P- U;; Setup Procedures ;;
& k7 B8 Y. I2 Z;;;;;;;;;;;;;;;;;;;;;;/ P9 f! K' A% o( C+ J' j
( z6 R! y3 [0 s+ ^) E' \' ~6 v' c  ?
;; Initialize the display by giving the global and patch variables initial values.
6 y6 D4 t5 J  q9 r) @# ~- H8 Q;; Create num-cars of turtles if there are enough road patches for one turtle to
% H1 @3 z6 g7 Q, n1 z0 M% i4 C;; be created per road patch. Set up the plots.
9 r  ~! q# s' P) kto setup2 z' s1 W' a% D6 _) V
  ca" V+ G/ d4 F' e/ s) V$ @, F
  setup-globals9 Y1 w! f' k& \9 M6 c  U

! t: \4 x/ @1 Z& o  ;; First we ask the patches to draw themselves and set up a few variables3 }+ N' a/ L. J* j* C
  setup-patches3 F. S0 i2 u$ {' _2 R
  make-current one-of intersections. T/ r4 i, O! j0 C# H3 x" f
  label-current/ P, X7 x- d6 G

' U( w4 H5 E7 W% ^5 R  set-default-shape turtles "car"0 g( }$ r! ?& o

% ?5 D- M( u3 d, b: e8 a  if (num-cars > count roads)$ R8 @6 d! j) k; f. L# G6 V8 }
  [
; I2 I0 [) i$ Q5 X+ h: ~$ D; {0 R' ~' V    user-message (word "There are too many cars for the amount of ", K& r6 i3 U3 H# K3 n1 ]) O  ]
                       "road.  Either increase the amount of roads ", J  Q9 g/ `. M& ~
                       "by increasing the GRID-SIZE-X or "9 f. e. x9 E5 r& x# T
                       "GRID-SIZE-Y sliders, or decrease the "
( B2 F, c3 W; S                       "number of cars by lowering the NUMBER slider.\n"
$ ?& ~2 c" n; d2 V% U                       "The setup has stopped.")
! R$ Q; q3 \7 N5 o' g" D4 h    stop
2 n+ o- I! {3 ~0 e7 I  ]
4 z( ?- z" h( v4 E1 Q8 p( [5 T& a3 [7 Q& G$ e6 K" y
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& ^9 m0 E4 j7 B' V; G  crt num-cars
' _+ N& w, ^$ b1 ^  [$ p2 R+ B: ?. r' |8 \0 D
    setup-cars
3 k' V8 j2 E, R8 d, l% n( [    set-car-color
2 l, _. N5 Y1 i1 h" m+ {    record-data3 B/ `. L: {4 e& c/ ~
  ]
% p& L- m. ?$ Y% d
, k' ]* }3 v! |  Q, u- q3 e0 y) b  ;; give the turtles an initial speed
# z1 B% q, q5 y: a) G! C  ask turtles [ set-car-speed ]
  Q. I. q% L7 n2 w7 _% [, j; Z% ?: q5 o
  reset-ticks- w6 Z  s9 b8 R+ S: K: B
end
- Q# F2 v: ^3 [" S! f/ _5 R
1 V7 D( Q5 c5 `, c% z1 u;; Initialize the global variables to appropriate values
) ~* Z# Y2 [$ U( O) g* r* e4 Xto setup-globals
# o( T) _- F. e4 }2 N  set current-light nobody ;; just for now, since there are no lights yet3 j  Z; T! |8 y# ?
  set phase 0. [/ {8 O, C" F) f* W
  set num-cars-stopped 0
9 G: G2 ~% c7 N) l  set grid-x-inc world-width / grid-size-x& t$ G8 O- ~/ Q5 g! m
  set grid-y-inc world-height / grid-size-y! _( [, l9 C. Y

2 n* g1 |; W" x& I/ w  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ q3 q. p: A- s3 K7 |
  set acceleration 0.0995 H& N1 {9 o; E+ c2 }% k2 B
end9 f# J: X( @8 d4 h; @, \

0 A: h, [& R5 c. a% o;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 w# r$ \' a9 [;; and initialize the traffic lights to one setting
; X, l- P$ j! \9 [. u& ~2 ?. g! Fto setup-patches, I1 Q2 z( I  i5 ~# g
  ;; initialize the patch-owned variables and color the patches to a base-color
5 i7 h+ ]+ X  d# Y2 k  ask patches% M; u; V0 D- G( p
  [
, [% Y( P! Y: a% E    set intersection? false% O  H- n7 J0 F2 N: t% z
    set auto? false3 u- D. V. O- m2 X3 F
    set green-light-up? true2 ~# C( Y4 h. p, t
    set my-row -1+ B: L8 t" B$ ~. P8 S; i
    set my-column -1% K8 k& N: O# H6 Q* ^
    set my-phase -13 d; o/ d7 s1 F
    set pcolor brown + 3; {/ v$ |# Z  b. E
  ]
, X- M0 v; `& b% @3 S# E2 \/ B7 ?
  ;; initialize the global variables that hold patch agentsets1 }5 @" \/ Z3 y8 |# H8 Q
  set roads patches with
: F- s( K0 c1 \    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 O2 f& ?3 C. Q8 S4 k2 C& K
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ r1 s1 F6 ~7 A+ ]2 \4 @: [
  set intersections roads with
3 ]" H" ]# Y. f" w    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& C/ ~1 A5 B+ y0 X1 @, ^# }
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 K5 k4 s6 c/ e4 F& I* D' }& o* V- R
  ask roads [ set pcolor white ]
5 i7 u8 |3 o  v1 R) I  Z    setup-intersections4 W9 f0 l/ @* G7 H! ^  }' k7 _/ s6 P' P
end
9 y6 D: S/ Z9 d5 g/ G7 u其中定义道路的句子,如下所示,是什么意思啊?
6 b( G6 r  [" ^0 @# | set roads patches with: c- a) z9 i2 x, B- c
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; V+ j, P2 q& A: M) R9 U    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 |. I9 V3 f1 Q/ l1 w7 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, 2026-8-4 17:21 , Processed in 0.015668 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