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: 8084|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。& V% }; `0 S& p9 t  k9 x% }9 W
netlogo自带的social science--traffic grid这一例子当中,2 P" g  r0 `. k* _' i0 l' O4 G
globals) U% K! T3 j6 F- C+ K
[) r$ ^6 U* M4 U9 h% [
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
0 Y6 D' @+ P+ F- i3 [  grid-y-inc               ;; the amount of patches in between two roads in the y direction: ^3 F" U. A% s" t" e
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if1 O" v9 ?3 O7 U; p- E3 U9 y
                           ;; it is to accelerate or decelerate* u1 G6 R8 C+ d+ \% O  C, a# ]  H& N. t
  phase                    ;; keeps track of the phase
0 q' u+ V  K) O& i  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure" |. o  x3 ~: C) p
  current-light            ;; the currently selected light1 `9 S5 h( B+ ^) c; S4 ~' Q

. G, F6 T+ @: J. Q  ;; patch agentsets
$ t# g& s+ k$ r3 a5 h  intersections ;; agentset containing the patches that are intersections8 ], h9 ?; n2 V
  roads         ;; agentset containing the patches that are roads4 @- ^2 j3 |" ]/ \
]
* |0 }# x5 e7 j% X* R( j/ N0 T4 L. @6 g0 b( M4 @7 \( f
turtles-own
8 y8 n1 \; k0 g% q4 E. |5 L[
' W$ F8 t2 U# r5 n$ K  speed     ;; the speed of the turtle
% W4 Z1 L9 t/ d& F7 [8 _  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
7 y* E4 D  O2 W" w3 j, m# V9 Z4 k  wait-time ;; the amount of time since the last time a turtle has moved
- F" f) w- M+ U& O, V]" |) W1 R$ X6 J, f8 b$ R
: k7 _# Q. o9 o5 R
patches-own4 H8 H# n$ h! M, Y) m, J
[
& |8 E% C3 K" B+ I5 A" S  intersection?   ;; true if the patch is at the intersection of two roads
" l" u6 k  I/ @7 E6 w. i" I; o  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.1 @* F6 @- C: b1 A4 A
                  ;; false for a non-intersection patches.3 E( t, L8 w. J! b
  my-row          ;; the row of the intersection counting from the upper left corner of the8 j; A9 N/ K) T, q! r
                  ;; world.  -1 for non-intersection patches.
: f1 s0 \5 @: ?9 A8 D" W  my-column       ;; the column of the intersection counting from the upper left corner of the# q5 |. w7 N! p# D: [1 O
                  ;; world.  -1 for non-intersection patches.
/ _' J: W7 l! O: g) u4 U4 g0 G$ K  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.8 f5 R$ |6 r0 f
  auto?           ;; whether or not this intersection will switch automatically.% r( y5 i: W% E
                  ;; false for non-intersection patches.3 Q5 X8 A) @9 s1 b3 R! x5 Y# D
]0 J( @& {8 p) e  C5 d
4 a/ U9 h7 J5 ~; i! W; @

; I2 u8 Q; F+ W;;;;;;;;;;;;;;;;;;;;;;" \0 ]: g9 f8 ~4 k1 K) ]
;; Setup Procedures ;;
3 W: X7 _7 ?0 i7 s% _+ h" L' T+ K;;;;;;;;;;;;;;;;;;;;;;1 l. D5 I6 I; Y: ^7 q6 a

: l+ z" ]' t- _7 H. v# D;; Initialize the display by giving the global and patch variables initial values.! ]5 K" Q- J# P2 r
;; Create num-cars of turtles if there are enough road patches for one turtle to+ N7 O! n! d$ \6 j! S
;; be created per road patch. Set up the plots.  k8 j% G, u3 F6 D' g; P$ v' g
to setup# D% i4 c+ r, t. a( `3 d
  ca
" D" Z$ e8 E  z; `6 m( D4 V: C  setup-globals5 a5 _5 v, N6 C& ]7 h: v
8 u* b$ x( ?+ r, Z' F
  ;; First we ask the patches to draw themselves and set up a few variables* L; ^; P) V3 m$ t7 {. c
  setup-patches0 `- ^+ A1 p0 V! v
  make-current one-of intersections
9 E) G) f0 s$ M+ }  K  label-current
5 w! Q6 l# x/ r( g# c
7 Y. ~. d& j! b" r( i0 N  set-default-shape turtles "car"& a0 s" f6 P; N) C
# Z  g3 a1 m* P# B# z
  if (num-cars > count roads)+ D$ V: Q- N+ f! l; A& s) I& F
  [
+ w3 S* Q+ o( f  a4 k" h+ |    user-message (word "There are too many cars for the amount of ". r" E0 o+ Z2 Q$ a
                       "road.  Either increase the amount of roads "
! y( @4 p, V+ r# n9 C! e                       "by increasing the GRID-SIZE-X or "( U  e: P! l3 M: B6 n& B% K6 m
                       "GRID-SIZE-Y sliders, or decrease the "+ m! X5 C( S, {& s  W( ?2 \
                       "number of cars by lowering the NUMBER slider.\n"& ^$ ~% v! Y; e$ J3 l9 r4 a
                       "The setup has stopped.")
# o1 w: p/ s4 g: Z4 j    stop, N* M$ J  m2 `4 Q; |7 d
  ]* R1 l, g, N+ y

4 v8 o, A+ h/ x% i" ?$ |, Z  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: J: d' r4 ?4 X; }+ r6 H$ {
  crt num-cars
) x) G; D: ]7 b. L) `$ n; y  [
5 I0 [. Z3 X. E. H# v  ?    setup-cars
5 g" [& q/ v- p& L% n    set-car-color+ z* B( x6 T, g" s
    record-data  V5 n' Q$ ~) H0 f
  ]+ |# i2 j# ]1 r  h$ `

; n7 @3 Q, l: {) k( p6 Q  ;; give the turtles an initial speed. E9 u$ ~2 L/ `4 p- g
  ask turtles [ set-car-speed ]5 Z$ U4 m9 }, W$ [3 r

7 N2 s7 g, R% @* z( K5 a+ F  reset-ticks, R$ e, {( m/ y6 b) z  \# e0 g6 M
end( y- h, f  W7 Z

1 A- ^! s( [, A( f;; Initialize the global variables to appropriate values
. A, T- V' T7 k$ \2 Bto setup-globals
; E9 B, M- O* D# I9 y5 t& F& W$ y  set current-light nobody ;; just for now, since there are no lights yet2 Y% k+ [( l' A
  set phase 0; e" b0 ]& `2 Y. z$ ^+ m
  set num-cars-stopped 0
/ I* [6 x9 \5 z* u  r) g  set grid-x-inc world-width / grid-size-x
3 ~' w0 x2 Y! k  set grid-y-inc world-height / grid-size-y
! l0 g# q  U- o1 |4 B
, S) j3 |" [2 `: k/ k  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 d6 p5 n% Z+ h2 `4 d% r/ _; e! a' @5 ~  set acceleration 0.099. {+ w/ o8 F8 E
end1 c1 ?, n! I8 R* X, i
' ]" P# @  C$ t% W0 m: O
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. ~8 s, q6 c, a9 q" i# ?
;; and initialize the traffic lights to one setting
6 e  y  `+ I7 e* a, @/ v4 K. nto setup-patches. A0 z' c$ o& m6 C5 \# c$ ?. v
  ;; initialize the patch-owned variables and color the patches to a base-color. R/ x' K5 H) K0 |% m
  ask patches# Z- b4 ^' C& F! P+ t; v5 W9 n8 \2 j
  [' j1 w, e. s+ p9 _3 h
    set intersection? false) V' m: W" n& i( S/ j- |6 c( u
    set auto? false
0 q! Y4 W1 ]& k; L$ @    set green-light-up? true
! W1 k8 B( w: h8 r& e+ W4 X; W( i5 U, h    set my-row -1
- l  w, r# H) o# }/ s9 G' t    set my-column -1
. q6 g4 Q# o1 z) c* M    set my-phase -13 m6 r; t! U3 c5 p; }! C" ^2 o
    set pcolor brown + 3
% o5 S8 g& ]3 b; K8 O; ?$ q$ a  ]
) ?4 x7 G( \* H( Y- ]! M5 h: p! }" K6 ]; Q6 C4 l9 M
  ;; initialize the global variables that hold patch agentsets7 [4 Q, O4 }9 H! k. r7 B
  set roads patches with' h9 o7 d) e' `0 `0 T& E
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- Q' I5 p, _; G9 i
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]  M. s, l. T) [9 Q5 w' p
  set intersections roads with
, z2 M' l- R0 N* b$ _6 {    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: T: k4 q% ?/ {& k( }& w/ m3 L* Y. v
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. K) g6 L/ d3 X' ^2 N
. `' ~) t/ ~9 Y+ R* Y  ask roads [ set pcolor white ]" X6 J$ R+ f" w2 X8 ?
    setup-intersections. s' [3 S6 B/ J0 D/ d
end
9 @2 }- U; x: S7 m其中定义道路的句子,如下所示,是什么意思啊?
4 _$ V, F/ K$ e3 A& H0 R set roads patches with
; @: F7 B/ l6 k2 w& ~- T    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 O+ F, k: I. r1 F3 T! W; i. {1 p
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ I& D+ A& w5 f& F( z  r2 C' ~* A; J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, 2026-1-30 23:21 , Processed in 0.016481 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