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: 7090|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。5 U! `! E  g/ \* h" z
netlogo自带的social science--traffic grid这一例子当中,
# e  Y# W4 |: C2 v5 [globals
  Q# h6 t8 p5 ^2 z2 y( f8 l+ C[: a  N6 J* H) e- n' p2 a+ J5 g
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
5 c' C6 l& E7 M# A; K& g  grid-y-inc               ;; the amount of patches in between two roads in the y direction! l! X7 _, i! I: ]
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if3 @4 X! M6 c( w' t( r
                           ;; it is to accelerate or decelerate. |, j+ Q' D1 f6 h- N* s
  phase                    ;; keeps track of the phase
4 Q) Z. ?" H& y. {  \- u  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure; r3 M4 T7 J: K% R" a4 A- ~
  current-light            ;; the currently selected light2 F, I6 ]7 z" l* i9 d

" Y( S, l0 K+ @( H  ;; patch agentsets; W: m' y7 a  h+ [2 a( g
  intersections ;; agentset containing the patches that are intersections7 ~# v/ ]1 `8 ^' t
  roads         ;; agentset containing the patches that are roads7 Q" `  m$ n/ q0 b$ c" F+ j
]
# F  W4 {' i3 C: X1 e; _8 U" I8 g- Z0 s! _
turtles-own
$ p; H0 Z" ?) Y# o8 y4 @8 L# E[! y7 H6 j* u4 m  g5 z( R
  speed     ;; the speed of the turtle0 |/ s- m+ |* U& \
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right0 m- Q- H8 x# H; J( S9 R, K
  wait-time ;; the amount of time since the last time a turtle has moved8 m. g8 q' ?/ _9 c
]$ {; s' N+ @% ~: \5 v. r3 Q
8 N% }4 d2 a/ e: v) A% [
patches-own
7 k3 H6 M' }6 S+ e! |  C9 M[6 B; v; A- x" o4 f
  intersection?   ;; true if the patch is at the intersection of two roads; H% A% @' C% h2 E7 B" D
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.! N2 [* X2 e& R# N& }
                  ;; false for a non-intersection patches., U  y, u2 }5 D
  my-row          ;; the row of the intersection counting from the upper left corner of the
2 L  x0 i% m- p9 A% M: @1 V                  ;; world.  -1 for non-intersection patches.
, _: l3 `# x2 q/ x6 X2 H7 f/ f$ O  my-column       ;; the column of the intersection counting from the upper left corner of the1 U! U. V; L0 `4 L/ D
                  ;; world.  -1 for non-intersection patches.1 j6 Y$ F5 W* [
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
; F' o+ j" `' o" d6 d  auto?           ;; whether or not this intersection will switch automatically.
' I; l+ }4 D3 \; [                  ;; false for non-intersection patches.
2 M4 n  o0 u( N+ L]& U! i, r$ b7 m2 d& p2 F9 Q9 j1 b/ L
5 [1 |) r& u4 g2 {1 p) w4 G) ~

6 v- B" f5 ]: }+ }# M;;;;;;;;;;;;;;;;;;;;;;
# O' m) I8 o3 t;; Setup Procedures ;;
  }6 s3 h* \( g6 J6 q! C;;;;;;;;;;;;;;;;;;;;;;
, T( o. }2 ~1 P
- I# e: x  |$ i5 }( I- }5 I0 Y;; Initialize the display by giving the global and patch variables initial values.$ @$ {+ N+ q& Z( p8 d$ R4 T
;; Create num-cars of turtles if there are enough road patches for one turtle to
; f8 o  M' S/ c  E3 k) y! A0 M;; be created per road patch. Set up the plots.
/ e6 ?1 F; D" C0 ~# Cto setup) A+ M- ]" z2 x% Q8 Z
  ca9 b. i0 ]# t$ w7 z; f
  setup-globals
' x! F# l+ @8 m+ i0 k8 E0 Y; j1 B6 [3 D8 X& z2 K5 L+ H
  ;; First we ask the patches to draw themselves and set up a few variables
5 ?, y) m) c' H) T4 g+ p  setup-patches; A& {1 ~% j6 q$ m! ^; ]. @
  make-current one-of intersections+ q2 U) _4 t: \# w: G
  label-current
, T+ x0 Q! g9 d8 ^) Q
/ H# t1 U. [' Q' N0 w+ j6 V  set-default-shape turtles "car"- Y9 h% I: W4 c, E% r: @  d
. o1 ^! A4 i  p4 D+ f# @; U4 ^
  if (num-cars > count roads)
4 b, Q" r  Y* S  [
6 E1 f: M+ V& l5 x1 P( n1 i4 Q    user-message (word "There are too many cars for the amount of "
" Q# e4 ^4 t3 F( a  f                       "road.  Either increase the amount of roads "
8 n+ l6 J, y: p* W                       "by increasing the GRID-SIZE-X or "
# [  f8 V) X3 ]% D                       "GRID-SIZE-Y sliders, or decrease the "
) I+ j- ?$ t- C& q0 I! K                       "number of cars by lowering the NUMBER slider.\n"8 t: U. ^+ G# w8 g# k) [
                       "The setup has stopped.")4 h5 x7 f& ^0 i5 S7 x
    stop, p* s( q1 ?% h8 _0 ^+ x
  ]
6 f) B! j6 l) [# r$ A: `8 u" X+ K* g
( C0 E# r  a, t. ^  m  Y8 I0 J  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ H& r8 h8 u' w' W  crt num-cars
2 V: E+ B" ^0 f: x1 h2 X  [; e: Q# |. f8 F0 Y! o) O4 }( [
    setup-cars0 f# I" s1 R! `$ G+ q$ k6 T
    set-car-color
6 Z, k4 u( p# j) t5 a2 }6 B+ ^$ `    record-data
/ h. K" I* u) z& e* h6 ~  ]
  Q; h. m5 |1 {, D
' T0 c6 P- O/ A1 Z  ;; give the turtles an initial speed
: X7 W7 j+ s! z2 n9 ]! R. C* A  ask turtles [ set-car-speed ]
2 d: ]4 q4 `1 S( |8 d; b& A1 n9 V% x
  reset-ticks( P" d- p: K+ e+ X4 ~& M
end
7 f+ j7 y" K7 r& d( c! b, i/ e& w; j" k! ^- i4 o
;; Initialize the global variables to appropriate values
' Q/ g/ \+ N0 t. zto setup-globals
& C6 _8 b: |* M2 K  set current-light nobody ;; just for now, since there are no lights yet" w* d4 b- O  O0 y) P6 t6 L
  set phase 0
2 {3 c/ M$ K! R7 Z  set num-cars-stopped 0' N! E+ V: ?! p( N0 _1 {
  set grid-x-inc world-width / grid-size-x
+ t) @; X3 h) n& [2 y  set grid-y-inc world-height / grid-size-y/ l' w3 l5 s9 x2 m+ o# o9 d9 |- A
+ b/ g' q. u0 y) H6 H% ?) e
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ J, V$ P) [8 I7 n& i) i
  set acceleration 0.099
; R9 x8 M2 t0 W. H  R- l* F# `, Nend0 m2 u- K' `3 {/ C& t

* q% G9 ?/ G5 L8 F7 D5 k, J# f;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* \: `. _1 \8 s1 n7 D; d3 Z( k; W
;; and initialize the traffic lights to one setting
; R6 d" L/ p0 Sto setup-patches0 k4 y% ?+ f  l9 {" u
  ;; initialize the patch-owned variables and color the patches to a base-color" s/ e' P2 k4 ^  ]# C7 T
  ask patches( p$ W7 P; V1 C% w
  [
$ C( p! O8 w( A" N4 J: ?% q    set intersection? false- n" v3 h- r  a" S& v2 g2 |
    set auto? false8 p: a+ l6 K! S
    set green-light-up? true- K9 P* e. w# c# S2 N
    set my-row -12 q. A. a4 y  V
    set my-column -1* o. ~+ m  {, d) X- x7 [2 c
    set my-phase -1- q5 H  ^( C3 h+ n7 l3 i
    set pcolor brown + 34 }% X( t0 h: j* Q' e* q, z9 W
  ]8 [! \2 a; c* v# p/ W6 S' l
. I# d1 P/ j7 L9 f/ T$ I
  ;; initialize the global variables that hold patch agentsets
  t; N; [5 ^, U4 W4 N  set roads patches with
: J! h4 C. i, J* E3 e    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 f; ~" v, I( ?
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 ?) P& E' v/ A  set intersections roads with5 d( r. ~2 c4 K) T6 W8 w
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* K9 F! V+ ?% j: @" q0 ^9 Y& q) J& P' O    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ J' F: T- c) c" u, B3 Y+ l
3 P" Y6 b# l! O6 [- a
  ask roads [ set pcolor white ]- o0 v) ^9 \& i! }
    setup-intersections. s. |1 c$ G7 Y* W/ d
end. T$ {8 z/ r; J2 X
其中定义道路的句子,如下所示,是什么意思啊?
* b8 x0 d- y: _# g# r* ] set roads patches with: }5 l$ @7 q* e
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 u8 t$ n& O: i. q& N: k
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 }. Y7 ^# @5 F) N# X1 b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, 2025-11-19 07:15 , Processed in 0.020368 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