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: 11301|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。( F/ Z) @* B4 d) R" F8 f( l, ~8 i5 Z, a
netlogo自带的social science--traffic grid这一例子当中,
5 a+ N% s7 a3 k$ C: u3 J' bglobals
- P- G  G) m7 w. w$ D[
+ B9 J* q6 N& Z/ `- N* f  grid-x-inc               ;; the amount of patches in between two roads in the x direction1 u& Q6 a( J* @5 v, w7 J0 W
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
4 _. o2 K3 f! O  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
3 d9 w& @* ]# D% B  \1 ?! W                           ;; it is to accelerate or decelerate$ d! M" M7 d5 q4 k2 E
  phase                    ;; keeps track of the phase% O3 r. O# T% H3 [! j
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
9 T% ^: g/ k/ a. P6 B  current-light            ;; the currently selected light
8 B' P1 w! ?  F' E
; C) C# H# ~! b0 j) J0 N9 s  ;; patch agentsets
  B% G6 p3 g" G* a( }4 K  intersections ;; agentset containing the patches that are intersections
. |# t/ n8 @! \$ v- U9 q  roads         ;; agentset containing the patches that are roads
' x0 i: l/ h7 {4 u9 C: Z& W; w; }]
! e$ `6 ?; z/ }, {" A! j- F! q, b% ~6 @% ~( r5 _# f2 g
turtles-own6 W) \/ r. d/ H$ B7 A1 {4 e- j
[
; ?; U+ m* y1 r) w/ K! f: h5 s+ y  speed     ;; the speed of the turtle: _4 P. x2 R( Z/ \- N# t6 n
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
: E1 C5 l; {$ S% h# l' g" |  wait-time ;; the amount of time since the last time a turtle has moved
+ Z/ W8 S, c5 O]
4 d  ]$ n  `' N9 X, g# v  V
8 i  k6 `& R" _6 bpatches-own
# \4 w/ z3 L! n) t) g5 \# j[! Y7 [& O8 w6 F3 z9 E2 |3 N
  intersection?   ;; true if the patch is at the intersection of two roads  f% }; k# H- n5 f8 V& Z
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false., S) j& ]9 M! w+ h
                  ;; false for a non-intersection patches.
6 U4 v- H: W3 k4 A  my-row          ;; the row of the intersection counting from the upper left corner of the) y, }7 l( `2 J% s
                  ;; world.  -1 for non-intersection patches.$ V5 C5 s- Z4 {( \* |
  my-column       ;; the column of the intersection counting from the upper left corner of the
: D; V3 J! S+ k4 j6 H* I9 Y  o                  ;; world.  -1 for non-intersection patches.$ Y. C& D/ H: K, r$ u
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.9 K( S2 X+ m% y! ~) g
  auto?           ;; whether or not this intersection will switch automatically.. U3 H- o8 T  w5 ~) ?
                  ;; false for non-intersection patches.
5 N7 M' e& K" N9 j]
2 D7 v2 c) L# R& W
; ~# W# {2 q: G8 ?9 ^; Q( h% Q5 G' g- q* ]% @2 h1 F
;;;;;;;;;;;;;;;;;;;;;;
  z# ~1 Y1 z3 l. m1 P;; Setup Procedures ;;
4 s1 t( M: m9 O( e; G% `# n;;;;;;;;;;;;;;;;;;;;;;# b4 `: a0 t/ n% r
* O6 R8 b! J' C9 j$ T
;; Initialize the display by giving the global and patch variables initial values.2 H- Z5 z9 E7 c8 p; _5 ?+ O
;; Create num-cars of turtles if there are enough road patches for one turtle to! P# H& Y4 G& P- [- K) r3 q$ E
;; be created per road patch. Set up the plots.1 S. @, v2 w! h$ H" \* v/ Q6 b  r6 c
to setup
! U2 B) B: Y8 `3 N& h+ z7 K  ca
& A: a8 ^' B( F  setup-globals1 a, w6 j. v( n3 X

, c" ]* _# r# `8 p) h3 \  ;; First we ask the patches to draw themselves and set up a few variables; M) R* G) D& O, X# V& W, [
  setup-patches% ^/ k2 k+ E( W8 _
  make-current one-of intersections
5 b- T7 F- i0 L, V, e! g. S  label-current5 a: B2 p# X" v6 C- H. l
7 d" i+ C) u. {% i9 s6 x" J
  set-default-shape turtles "car"
' _, m- t  R3 {2 _0 v" G; U3 J- W) m3 K) z7 [& A% o6 g
  if (num-cars > count roads)
6 ^. ]0 e8 Y" I  [
1 Y" g. Y. I/ \. C- Y    user-message (word "There are too many cars for the amount of "
6 b: k4 h2 v9 y' g+ p                       "road.  Either increase the amount of roads "
: H7 L$ i0 G/ x. K+ k                       "by increasing the GRID-SIZE-X or "
* T3 Z1 i, w* E2 Y' H# h                       "GRID-SIZE-Y sliders, or decrease the "4 \: r- \2 ^" Z, B) G
                       "number of cars by lowering the NUMBER slider.\n"; |5 c0 q6 s& V/ z/ b
                       "The setup has stopped.")# O  B1 j- y$ S, j! K" }, R
    stop
3 W: R9 h4 r4 h  ]
$ u/ B. h0 N* x% G  e% }4 x
9 Z' u4 N; b/ p& ?7 P  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: R5 N2 }* k. F' Z
  crt num-cars
0 {; x4 Q" ]% l. d  [( n  J$ w. _9 E) O0 S
    setup-cars
% d, Q  H6 r. ^4 J: Z; }    set-car-color& |% ?& Z( w1 P
    record-data0 j6 l/ g! r; t6 Z( Z7 q$ a
  ]) M" W6 x0 l- g1 a4 I) ^9 Y4 t: k

4 ^  a* k9 ?* d/ u4 y) l( H  ;; give the turtles an initial speed
2 g0 H, T) {- S' ~6 Y8 O7 W' f9 ^  ask turtles [ set-car-speed ]
4 y6 y! p. b7 W/ Q% z- b$ D! l0 v2 f5 m3 [
  reset-ticks
* f, G2 h9 X6 F% Q- U- j- Y" kend
+ y& s  J) P9 e/ }+ x4 O+ d
2 p4 `3 z4 e( o;; Initialize the global variables to appropriate values7 y4 \& p, a5 h' P
to setup-globals. H& j% N0 ?, j, g+ ^: q
  set current-light nobody ;; just for now, since there are no lights yet7 B2 O% Q5 L  c
  set phase 0
8 p6 D  B9 j' o% a' T  H1 a  set num-cars-stopped 01 E+ P7 ^: _4 L
  set grid-x-inc world-width / grid-size-x' v& c" r4 S+ ]$ b+ c1 h2 a
  set grid-y-inc world-height / grid-size-y
8 z5 G  U4 {6 _- a& m. i3 H& l0 L( p4 K3 X: B; v9 p
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 N" g  ^# x/ K9 [
  set acceleration 0.099
5 h( s  I/ h' S0 {end  ^) H3 e$ G, z6 `7 X  h0 t3 D7 V$ n, u

7 X% F: y) K, X9 F;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! \" P+ O9 B" h* ^: E7 u
;; and initialize the traffic lights to one setting
; d% Y9 k$ y/ Q" m! i- Y) G# t: M6 hto setup-patches. }0 S% \1 ?8 a" X6 x8 I# _
  ;; initialize the patch-owned variables and color the patches to a base-color* \0 f# l' ~9 l' L3 N, z1 G
  ask patches
4 O5 \2 s- l- ?3 a9 W7 L  Y  [
/ Y% G% U$ T, [8 }) O9 b9 S    set intersection? false/ B1 u- R. m  K7 A
    set auto? false* a! m# z  C7 J3 X' \! u. a! Y
    set green-light-up? true& }+ y  i5 h3 C9 I
    set my-row -1
, A7 g" Y" m& a) L. S$ ~7 t: n! p    set my-column -13 h+ V/ q5 t" O2 A  i' x# s
    set my-phase -1! `3 h/ @6 @, _) N  |
    set pcolor brown + 3: ~2 Z, u" y& f4 {, ]* X% k( A
  ]
4 q& y5 ?* a/ }4 G$ I( h/ \4 p
& V3 q9 M, j& C# `! \, M) r  ;; initialize the global variables that hold patch agentsets; g9 Y( T5 u% l% }3 s( H+ J
  set roads patches with
6 E3 f8 W8 `5 F% D    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 _1 }- M* m+ B0 o/ j+ h9 c
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ R* s% r% F8 G: S  set intersections roads with; }* e/ r8 d; t$ l: _9 x2 t
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& q  W! w/ k& g1 s: _: b    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* ^. o! Z" f' d

& I- f* H( H9 k+ C* `/ P+ M( m) f  ask roads [ set pcolor white ]
' l3 ?+ I# P# H7 x    setup-intersections
6 d% p9 n. \# [# {, p3 Q0 v1 M  }end
' r$ r2 z0 i  R; m6 w; a$ T5 l其中定义道路的句子,如下所示,是什么意思啊?
: _4 L$ @$ L. M( O# t9 P/ t set roads patches with$ l. {  n% t' v5 A. l" ^' {
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" f. E3 s, M  N    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! w8 P; f( s* L( a, G( H: u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, 2026-7-24 09:21 , Processed in 0.012392 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