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: 8071|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。( H# j5 o# _# ~2 f
netlogo自带的social science--traffic grid这一例子当中,' l: _, F: ?2 c& `1 M. x$ ?% {# k
globals
& F: U& Q  U! V[
& Z3 ~: X) j, P) C! D; U  grid-x-inc               ;; the amount of patches in between two roads in the x direction
( q# u# @6 q  E9 Q$ p1 d; @: W; z# s% m  grid-y-inc               ;; the amount of patches in between two roads in the y direction2 `7 U6 w- V; s' k6 ]* T
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if* k" T& C, @8 |, X4 s
                           ;; it is to accelerate or decelerate
# _! Q. e3 w* Z9 {  d  phase                    ;; keeps track of the phase7 J* h4 O: N0 t* F6 T; Z. z
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure# U) Z0 K3 a/ q, `5 |2 l# z
  current-light            ;; the currently selected light' Q3 K- V, C  l3 e

1 T! W* ^! }/ r1 X  ;; patch agentsets. q8 b4 z. r! h% d% E, k/ y' G
  intersections ;; agentset containing the patches that are intersections/ d+ K5 j8 p9 k0 [  P, i2 w7 t; E
  roads         ;; agentset containing the patches that are roads1 N' ^" a7 d4 ?" G; c
]
. ^: p( ~/ m' ~' e
- t9 \% c- f8 b" ]# q# Lturtles-own
+ Q: e' ]9 z" Y( N[
  R/ \2 S& w1 s* H* w* T  speed     ;; the speed of the turtle) R1 s' t2 |  y7 X) |
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right; _, h' k: K7 d5 c
  wait-time ;; the amount of time since the last time a turtle has moved; u1 K, w: B6 k( W
]( E$ s4 d/ ]/ Q: G; k
$ i$ s3 Y" N) D7 F8 e1 k7 x$ @
patches-own
2 ~/ ?% b& z  c. A[' [3 l. z  z4 E8 @3 r) I
  intersection?   ;; true if the patch is at the intersection of two roads
' n- K6 [' e7 @% F9 _/ }0 R6 |  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.2 F: g6 @* d  L9 {+ s& S
                  ;; false for a non-intersection patches.
  q$ h* b7 g. d# d& ?8 d: C  my-row          ;; the row of the intersection counting from the upper left corner of the
8 I6 s- _4 K9 o9 j                  ;; world.  -1 for non-intersection patches.
% H9 u/ ^' Q4 \  my-column       ;; the column of the intersection counting from the upper left corner of the
9 k" V  B% N+ R3 L$ z$ U/ k' w                  ;; world.  -1 for non-intersection patches.
1 i% J9 x0 B& s8 F+ q6 Y  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches." H, }% \0 B/ \' S8 v  l
  auto?           ;; whether or not this intersection will switch automatically.+ s9 t. ^+ K& |, g# P
                  ;; false for non-intersection patches.
9 C/ y* y2 ]3 p]
! m1 y* W, C$ V  ]* H' e" t
) i' O: N5 V9 W. E9 Q& h: E  d9 `% K; M/ g7 M
;;;;;;;;;;;;;;;;;;;;;;% G5 r, e% d! Y
;; Setup Procedures ;;
" g: H# d" z( ^% X7 n;;;;;;;;;;;;;;;;;;;;;;+ C; ]  A1 U1 n. u' T. l# ]7 ^
, {7 }6 H* q0 m4 N$ x
;; Initialize the display by giving the global and patch variables initial values.0 {3 q! ?2 J; ?
;; Create num-cars of turtles if there are enough road patches for one turtle to
$ o, n0 A) q" Y7 A" l0 I% j;; be created per road patch. Set up the plots.$ p) E3 d  N- H( r1 C
to setup. [; y# `8 l% i: l& b4 J( _. d
  ca  p' u% v8 f9 `- i7 j$ O# g
  setup-globals; B& k4 }- y5 N# P7 F

- O& V1 j- S3 g  ;; First we ask the patches to draw themselves and set up a few variables
& U% ~% o8 r1 Z& {- r) I0 H5 k3 W9 H  setup-patches
6 I0 h4 |/ e! k  make-current one-of intersections; N8 c3 ~' ]3 L; R/ Z* r
  label-current
- D' |. d( J( S4 _( o- ^6 j1 q; P  H/ `7 M( j3 g
  set-default-shape turtles "car"9 Q( M7 s6 C' A2 J8 ]5 I, y5 X7 N+ Q
1 m5 c7 w; X% @" G; f- R6 e! q
  if (num-cars > count roads)' E- w, ]. F8 a  ]5 b, C; a, s
  [0 i" o1 H$ L( r( X! e
    user-message (word "There are too many cars for the amount of "0 a7 G& w" {9 s2 i- B% O2 A
                       "road.  Either increase the amount of roads "
; Y1 q" S( t* d# y                       "by increasing the GRID-SIZE-X or "7 C' B! M( ~3 o0 ]# V( z6 D7 l
                       "GRID-SIZE-Y sliders, or decrease the "
7 w1 z. u+ m3 ^1 U. {; ^! C                       "number of cars by lowering the NUMBER slider.\n"8 m5 x' x- Y( V& u
                       "The setup has stopped.")
4 A7 u. t8 a  o! b- U) R$ c) Z    stop
$ ~$ j  K* U$ _( b  ]( m/ Q' @. e+ D% |/ ~0 U- f7 C
' T! @; U# e$ F7 O0 K# \4 q8 M
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ l" Z2 G0 U5 z; N1 P# V/ `% d  crt num-cars8 v& m! \5 I5 v1 @* ?
  [
% M. d. V- \5 I; s. x    setup-cars
7 g9 q! ?! I0 k" i2 K    set-car-color6 l. ^9 V7 w# q7 i- Q
    record-data6 F; b6 G8 Q3 m, n2 B$ ?
  ]
1 `# K8 h7 `" J; f0 e% @5 O/ e# l8 {3 p
  ;; give the turtles an initial speed
. r& m/ f' v4 {+ P+ M1 \9 s0 _  ask turtles [ set-car-speed ]
! u1 b* m" I7 W+ ?! Y+ W8 t: ?) g, a) W- q
  reset-ticks$ D5 _* o/ p) n3 ]4 [6 Z* k
end
2 V9 e8 G: W1 h! ^& v6 N8 b( i+ A# m( V" @0 @1 k/ B; y" e
;; Initialize the global variables to appropriate values: y: K# c6 m9 H7 s7 e  J; n
to setup-globals. _# m2 Z( w- _  k" I! |6 M4 P
  set current-light nobody ;; just for now, since there are no lights yet
. Y2 n: \/ `. U* p3 v  set phase 0
1 S& z. Z0 V/ H2 v5 o  set num-cars-stopped 02 x9 j! M  x2 B- k& e  k* r. l7 M
  set grid-x-inc world-width / grid-size-x
4 a+ S9 [7 n; W* d$ Z  set grid-y-inc world-height / grid-size-y
% E+ Q+ @6 c8 a2 O7 P' y# f9 Z+ g9 k! t& a& ]  v: ~' Q) F
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' S3 J0 ^( R' Z! A5 a! U
  set acceleration 0.0993 m2 ~# G1 U) l* I
end+ H/ m' V# H7 e
5 z( w* U" r+ V  h" Q% j8 T- {6 b! L  U
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* W& L. C5 f* q/ ]' i: A2 {- Z;; and initialize the traffic lights to one setting' l5 l1 l9 Z' m# [0 q+ [& b
to setup-patches$ q- P4 s! A3 N1 G" \
  ;; initialize the patch-owned variables and color the patches to a base-color$ u6 M1 v' {" \! \9 z6 [
  ask patches$ m' P" N. U  C. i
  [
# {8 H# n3 j6 H5 x) ?  v    set intersection? false
& Y6 A( H8 F' L- Z. n' b    set auto? false  ^+ l6 A( C1 Q! ^  N; {
    set green-light-up? true
7 b! i2 m- s9 ]& x$ O  \5 [    set my-row -1
' I! f1 P( q; v6 v, e    set my-column -1
% e; w+ `4 W1 ?* t# f* z    set my-phase -17 i, F# r- l) R2 a) ]
    set pcolor brown + 3
7 P7 e. Y, o5 |9 c) Y  ]' F1 e* N. n) w) r4 h9 U

! U. _7 H: F1 @2 U- W* P5 {/ @  ;; initialize the global variables that hold patch agentsets
3 i0 h# k5 c9 v' C, V  set roads patches with
3 x' @# U; L" D! i, u8 W: m    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( ^0 K! z; v" n9 r. J' e3 Z    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 w) O9 D$ k" }7 E  set intersections roads with
& n8 ]! N* N/ Z: y6 h    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ ^+ H( k' q8 t4 R  q3 F6 L
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 d% Z3 r- R. U" D
3 b" D  h# |, i1 J
  ask roads [ set pcolor white ]% P5 ^2 |9 v/ Z' m4 C" z
    setup-intersections
8 X, `- R4 M; O' w/ vend
& X' g8 R7 h: [7 ~( N其中定义道路的句子,如下所示,是什么意思啊?7 j* @" A/ o8 G& ?  k' J5 `/ s
set roads patches with( \2 {: ?$ y/ ^" E' r- i
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) f2 \0 W- N3 f' [3 \& N    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; x* m: b. ]: c2 F/ k
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 11:02 , Processed in 0.021221 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