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: 8516|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。/ l2 y3 p1 v+ Q
netlogo自带的social science--traffic grid这一例子当中,1 g2 o  M( m4 G6 f6 }
globals
" r/ j4 A" p* Z% t2 ^0 s. g2 B[
8 |/ d# O) ^/ v  grid-x-inc               ;; the amount of patches in between two roads in the x direction
, \! P/ I4 V! ?& }1 n8 v5 T4 H  grid-y-inc               ;; the amount of patches in between two roads in the y direction2 E8 e+ a& I3 i" ?
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
# c9 R) U5 X8 l: r" w" j& L& O0 \                           ;; it is to accelerate or decelerate
: D  I% ]) C+ Y+ m6 T4 V: _  phase                    ;; keeps track of the phase) n- k1 p+ C% h; Z% W; z7 X
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
0 C  w: Z' Z. J+ m3 D* k: ?  current-light            ;; the currently selected light* j8 t# W' e5 r5 @1 w8 j7 i- ^

/ z- x8 R+ T# ~6 R) E  ;; patch agentsets8 L% c2 t5 x% J- Q7 n, i' f7 d
  intersections ;; agentset containing the patches that are intersections
  z9 K$ W7 K1 y) c' Y% o) f  roads         ;; agentset containing the patches that are roads
! M+ l0 F, k4 r- D! x]5 y, Z/ @8 Y! @5 _( Q5 s! _
# G* a% k# S, Z7 M( a0 H
turtles-own
0 }# J: r. Z, Z' q( {: k, ^[
$ `; F  R# H2 v- h. m% Q' [  speed     ;; the speed of the turtle4 A- u! j' |, ?1 Y$ h2 O1 F* N
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
& A! E/ C3 B- f7 c' P! E  wait-time ;; the amount of time since the last time a turtle has moved4 p. ^5 K. d% L1 L& s
]- r3 ?, E3 z' u. v( f# @! ~3 D8 ?

  D4 `. @8 g! v3 V! ppatches-own
+ ~- d5 {$ M, E* L/ e[
' z: V* v$ m+ h9 H  intersection?   ;; true if the patch is at the intersection of two roads5 i8 Q5 C+ x! n$ E5 [8 R- C
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
% U+ }: r1 w$ `9 j' h# i' W0 m) p1 H                  ;; false for a non-intersection patches.6 ]9 ?, }& i, d! F/ _
  my-row          ;; the row of the intersection counting from the upper left corner of the
) z$ |; y/ ^" A4 w0 m. }. I                  ;; world.  -1 for non-intersection patches.& N) O/ m8 `4 R; O
  my-column       ;; the column of the intersection counting from the upper left corner of the
' Y' v6 c8 d4 \( k                  ;; world.  -1 for non-intersection patches.: Z* |3 o+ d: d
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
$ ]' f6 L# q) D  auto?           ;; whether or not this intersection will switch automatically.1 A3 w' T  c, @3 C
                  ;; false for non-intersection patches.
( i) z' E9 p- i4 b0 w]
# j9 \! l9 f3 i+ A" [. R" P# h; T9 R

" y# s% \, M$ a& z;;;;;;;;;;;;;;;;;;;;;;
; p( K3 J- w0 z2 Q;; Setup Procedures ;;' O8 G* _  k9 G& H
;;;;;;;;;;;;;;;;;;;;;;5 s' {' H& U: p( I

! r* \2 q6 v+ R; i# r;; Initialize the display by giving the global and patch variables initial values.
8 s4 ^) o" [) U9 R0 A9 |;; Create num-cars of turtles if there are enough road patches for one turtle to( O; |! x. ~6 a' c7 x' j% `
;; be created per road patch. Set up the plots.. O, G) t# U0 m2 {$ ]
to setup
2 l- U- _' {( S6 y9 F/ S4 ?4 K  ca2 r; ^" K2 L7 D) r% a9 y! b
  setup-globals
3 u* k# y+ i' |5 R$ `# D& M, f
1 ]9 u2 S. ?) B( N  X  ;; First we ask the patches to draw themselves and set up a few variables4 i. g0 ]9 n; Z6 J' T! c' b
  setup-patches$ m8 f2 ^4 }: v2 D+ S& R4 Y
  make-current one-of intersections/ E! Y1 s' i/ I) \# }) y
  label-current
3 l/ S/ q% M# P! ?) l; S; {( K
( F, J8 o- e( R" ]$ D; ]  set-default-shape turtles "car", R: v, [" w8 V; u
- D; m! ?: Y/ \( B* Y  Y+ |  s4 r
  if (num-cars > count roads)
2 X. L, n6 g5 n% j" Q- z- P2 Z5 B$ G  [
) S8 l' h$ ]. [1 k" H    user-message (word "There are too many cars for the amount of "
. y; x: o% ?8 \3 n+ A                       "road.  Either increase the amount of roads "; C7 @/ A& ]4 ?; _7 F6 a+ W
                       "by increasing the GRID-SIZE-X or "% ^, f2 s3 K, F* g
                       "GRID-SIZE-Y sliders, or decrease the "
) Q1 T7 `; z% ?                       "number of cars by lowering the NUMBER slider.\n": k! z% m. n8 D- [
                       "The setup has stopped.")6 l) o% c8 E9 \$ w4 g
    stop
0 T- i% ?" |" f) z  [" [  ]
" M3 R8 U& u8 ]% B9 e' O
6 C/ `3 x* T! w* G8 T  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 y4 m- [+ D1 [$ L: o  crt num-cars, L, ^4 U1 J% m' g1 O
  [
3 E7 E& b$ w; a    setup-cars
& ^5 K" _+ @- |; L& C& b2 ^" t    set-car-color3 {- Q5 t2 K% a% I$ U- t8 T
    record-data$ L$ W5 B1 k/ y/ h! O4 K
  ]( f5 G. m: j, M* _7 [; c% K5 Q
# X& u5 J9 J2 Z( H
  ;; give the turtles an initial speed% u' q6 ]0 d: R1 z
  ask turtles [ set-car-speed ]- u' F/ g1 o6 Z5 S& i" u9 }) q

8 \( X" S; E  B: L& Y  reset-ticks1 y* [: J$ e6 L8 g4 _8 }' [# j/ p
end
3 j9 e/ e& ~* @7 R* b9 O! k: N! `0 d/ w1 {+ w$ b% ?
;; Initialize the global variables to appropriate values
: S4 o; _- N. O& n4 Vto setup-globals+ ]8 h' l: h" A; n" q
  set current-light nobody ;; just for now, since there are no lights yet" j! s: F2 v8 f$ G4 B
  set phase 0& c2 Z" Q: u/ F9 P+ _% ^( \
  set num-cars-stopped 0
8 J2 B3 A- u" U& s  set grid-x-inc world-width / grid-size-x9 F6 k6 c, U! p% x0 ^% m
  set grid-y-inc world-height / grid-size-y
9 D! F; N$ T/ o9 a
7 s7 b8 V. [0 x. G( y  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' P" [9 j+ ]% j- O  set acceleration 0.099
! ]% O8 k8 U5 R' Uend  v: N6 `" f1 ^( Q

% [$ Y' Q, T: ]5 b8 \3 w# _;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! @" E: c& k: o+ b2 ?; V2 I/ {
;; and initialize the traffic lights to one setting
, U* _( H8 r8 V' P% ~5 v* y% V- Pto setup-patches6 _9 t5 o- s# D7 N1 c) r) ?
  ;; initialize the patch-owned variables and color the patches to a base-color4 u2 N5 {4 y% l4 L1 i% h
  ask patches4 Q6 K# C  H* W+ V6 z
  [( A$ Q- _9 P. @1 g1 O
    set intersection? false
+ G7 m! q# e; {2 F    set auto? false+ U' Q! k* s' f: l7 s* m* P
    set green-light-up? true
, S# l$ A) F. R  X5 N2 S    set my-row -1
+ {! F9 M6 m! {! d9 n4 P* X1 B    set my-column -1
# r! {+ O4 W8 N: n0 k+ a6 c: S    set my-phase -1
+ V( p1 M$ K) b    set pcolor brown + 3
" |. ]  `0 q# s  ]
2 z% u% _3 M- D3 i
, L" S/ l. `5 a$ J8 J" n) m: j  ;; initialize the global variables that hold patch agentsets
* J* k8 ^# |; Z# @  set roads patches with( l/ B6 J( K0 D( g% _! y3 M2 n
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 X$ K; I! X$ \! A* G! D    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" S3 Y5 ~9 E1 ?9 |
  set intersections roads with
) l; p8 D7 y! j1 F* c    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! c: o- A% h2 Y. }% w    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ n! |8 _8 b  @# O9 D) c  c, }
* U9 j% t! q3 \$ u  ask roads [ set pcolor white ]
) I% f, U' K* M  }    setup-intersections
8 T) v, t, f4 [" k' C8 {; P4 `end
( Q2 m% ^8 Z9 A$ r/ x, i! E* i其中定义道路的句子,如下所示,是什么意思啊?/ H* E4 k% @9 J
set roads patches with( ^* u! z% a8 F3 m
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( P8 q$ j% c$ F: U
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& l  n- L; ~3 l* v6 {4 ~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, 2026-2-22 19:46 , Processed in 0.017768 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