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: 9397|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。6 [/ e: x8 \5 q9 r( {. R; V
netlogo自带的social science--traffic grid这一例子当中,$ @$ I; q, x7 f( m3 }6 v/ K
globals0 x$ l* F( }" w
[
5 o! ~  P) G& Z; `  grid-x-inc               ;; the amount of patches in between two roads in the x direction$ j$ Z* K6 {5 ?% S1 {
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
: T5 E4 I/ m" d& p; y2 p  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
& u( y+ Z2 G5 g: s/ C6 ^! o                           ;; it is to accelerate or decelerate6 f; T8 G7 n, }5 G$ l5 I# g
  phase                    ;; keeps track of the phase
; W, z- ~* g$ }& P. C* z& u" Q7 M9 F  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure+ }$ j  b0 r8 ^5 C- {
  current-light            ;; the currently selected light  k. w. ^$ i' M& V+ I& I
& u$ p9 G: N. ~: }5 w: P0 u
  ;; patch agentsets7 v$ J2 `$ e9 n+ h! h+ C' Y1 j) F
  intersections ;; agentset containing the patches that are intersections
) q: U. X$ D. H: w" m) ?1 g  roads         ;; agentset containing the patches that are roads) Q: Z- s0 G" [6 b2 Z
]( M% t, e2 Z7 [; Y9 y4 y
0 n0 ^+ \* q/ u& V( `
turtles-own
- ~' }# t3 m* I[
: B9 ~( r9 `3 E3 X; [  speed     ;; the speed of the turtle
/ i& l  S! ~3 v4 l5 v% K  up-car?   ;; true if the turtle moves downwards and false if it moves to the right" @' ]+ n1 ]$ R; C
  wait-time ;; the amount of time since the last time a turtle has moved
2 K1 {; t3 q% ?/ T! x]
& P% D1 j8 S: J2 q9 E, R" Q
* q3 B- ]$ Y  W: C: s( bpatches-own! R0 s% Y8 q6 m/ }4 Y' X, M
[
; y8 L6 b' d/ K- ^6 b  intersection?   ;; true if the patch is at the intersection of two roads, G; s5 _! A/ i! I( j& \& \
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
0 A9 ^" w0 r5 }" {  o4 n  a% s. B                  ;; false for a non-intersection patches.  h' m* d! W- K2 w
  my-row          ;; the row of the intersection counting from the upper left corner of the
% ?, r9 H# Y7 [                  ;; world.  -1 for non-intersection patches.
2 P* T/ w9 d5 T  my-column       ;; the column of the intersection counting from the upper left corner of the. {% B* t1 g8 h6 h6 n
                  ;; world.  -1 for non-intersection patches.
5 c5 G/ h# M' j( c" Z6 ^# K% `- J  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
. c! }6 @2 y5 ~4 x3 [7 ~0 b  s  auto?           ;; whether or not this intersection will switch automatically.
9 A1 T- ~; P2 L2 S# |8 O; `: e# t2 V                  ;; false for non-intersection patches.
- W, u# ^# b( {1 C% `. H! b]
" o% j/ _# p- ]% q* I' x+ f
& A2 N4 x# `0 y2 s( o1 i7 \: W' o5 o) ]  l* c
;;;;;;;;;;;;;;;;;;;;;;
1 l3 A& c. [0 x$ D) k6 _9 Z) l0 x3 k' O2 ^;; Setup Procedures ;;! O+ y9 e( C5 A) Y3 \
;;;;;;;;;;;;;;;;;;;;;;8 O7 \! D5 X8 B+ s) s& s
1 i1 x2 a! `9 B1 B
;; Initialize the display by giving the global and patch variables initial values.4 N! c; k7 N. {9 V6 D# c
;; Create num-cars of turtles if there are enough road patches for one turtle to
+ z( o9 V8 L" O;; be created per road patch. Set up the plots.  v- ?+ Z$ t; g3 g4 Q% y; h
to setup2 y: ~$ u7 O2 ~# I
  ca- P* u0 q# \: n; g# `
  setup-globals/ s! W# }! s: k3 A5 _- }7 e
$ v* F- h: U' y
  ;; First we ask the patches to draw themselves and set up a few variables3 h8 S4 S4 X( Z; b: C
  setup-patches3 [* M7 H4 V9 t
  make-current one-of intersections
6 m) H/ Z5 ]1 S  label-current
# L* u' g* [( T& ?0 P% D
6 S3 C: [( B$ i* X$ U$ k  set-default-shape turtles "car"
( {5 I/ T4 m! c8 i/ J% R5 S
$ Y& }4 j1 R0 r! z  if (num-cars > count roads)
. P8 S  O) B6 v2 y  E  [
7 J' ?7 e3 S. d    user-message (word "There are too many cars for the amount of "
* X% ^# z# K- d                       "road.  Either increase the amount of roads "7 O4 r3 p: x  J0 v
                       "by increasing the GRID-SIZE-X or "
: b+ l; z. [. [; w; i$ j7 D" s* `                       "GRID-SIZE-Y sliders, or decrease the "
/ S( N/ q6 q  V' E- p                       "number of cars by lowering the NUMBER slider.\n"! i/ o; {* z" Y& |: D$ d: }6 E
                       "The setup has stopped.")1 H" b! Z; h5 [
    stop
1 y$ b7 E! W- r. c: w1 b2 b+ u' w" b  ]
% @4 p* {: I* }: y2 k1 n" o
  Q; }+ U4 I' O& N1 Z* P  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 w. [2 Y- b8 [: `7 h; U* u0 N
  crt num-cars5 D: G) `6 J6 h& z4 q* l
  [
( f+ z  h' I+ T4 g    setup-cars
; K9 j# z; h( o3 c+ q% ?! T    set-car-color- k9 ^6 [2 }3 q( {
    record-data
, ]* }% ^& a+ P: p! _3 Z) s6 G  ]3 [+ ~# b7 A/ {$ u" M3 g

9 T7 s) H5 V) [' R% Q. i  ;; give the turtles an initial speed
7 A& j3 M6 p+ Y. B* W5 ~  ask turtles [ set-car-speed ]* B  F* T8 J+ O) F$ E
  a  V- n; G& O4 ~2 h
  reset-ticks
  _5 o6 j3 T: c) H7 i& ~end% Y. B  b: Y, O3 f
; J9 M- ?% D, Q& B
;; Initialize the global variables to appropriate values
5 a2 z$ ]3 L$ I1 r6 h  x) Hto setup-globals, N! g: X* a" G, z
  set current-light nobody ;; just for now, since there are no lights yet
: ~7 ^" K9 o0 M- A1 M  set phase 08 u; n/ f: p& Z  v! }+ g
  set num-cars-stopped 0
2 O& B: T  t* b' A: g4 z0 T! e  set grid-x-inc world-width / grid-size-x2 I5 h; I7 E8 u1 T& b* ^& {$ `
  set grid-y-inc world-height / grid-size-y
8 h3 ]  c7 u) M0 Y0 a, z) h  x. q. F1 c  g! F
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
4 v, X3 m8 U2 t; c. d$ p8 ~: z  set acceleration 0.099
! v3 R% f8 x! D" D( ^. @end6 p' {. l9 Q' g, c6 b  `- n' c5 J

8 a% T0 k4 @1 [0 ^5 H0 ]  B1 v;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: y+ p" Z1 {9 Z( Z
;; and initialize the traffic lights to one setting- k* W( r) k5 ^6 {1 ]
to setup-patches( a( x) o+ n. s' x; ~1 f) e: h
  ;; initialize the patch-owned variables and color the patches to a base-color
" G, K% ?! g% n1 R" ~  ask patches
0 Z, R5 \* B# U6 |6 M  [
9 n( X" X. w" y6 Q5 w    set intersection? false
0 f% e( ~, G# Q/ s$ g, h. H1 D& Y- F    set auto? false5 {! U9 a9 c/ X) F5 Q
    set green-light-up? true
3 y& M5 m/ T+ J7 b    set my-row -1
7 x, u- s6 _& A4 w) p% c- L    set my-column -13 v3 P7 e7 u# E3 R3 M/ c
    set my-phase -11 D- F7 k* O' T( a" w1 E
    set pcolor brown + 3, b6 q& o, K7 O; d/ K7 I  A
  ]# ~$ D) N$ I4 N. A# l

" I4 y6 y5 P) X3 ^  ;; initialize the global variables that hold patch agentsets
; ^" W3 E' y% ]& e  set roads patches with8 V6 A* P) E; N4 y
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. r- L$ v# P, ^" j
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 z( L$ l+ `* o4 ^( I  u: I4 r  set intersections roads with
4 `3 c4 T# y' A# y0 x    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ ?1 m& F3 I8 J$ K6 h0 o+ B    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 r3 h" L9 {( |" B* [- g- f% C0 s% b8 ^. i
  ask roads [ set pcolor white ]
+ h- z5 s& `; D7 h& y    setup-intersections0 ]7 D- w& g( K0 D
end+ U3 Q, S) K2 u7 D. o: C" c# y
其中定义道路的句子,如下所示,是什么意思啊?% `/ m5 P4 N  e% b
set roads patches with9 g$ r& R3 b6 s! U. w1 R. F" e8 z
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or  @- |& t& {5 @7 L. G+ |0 d6 `
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 g5 e8 t  K# w; o9 ^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, 2026-4-13 14:10 , Processed in 0.021829 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