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: 7245|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。  e) O) V% Z' O- R2 ~
netlogo自带的social science--traffic grid这一例子当中,2 O$ Z3 t# z4 {: y
globals
1 D: V5 |& C) A6 ?3 a: N9 t[' g- _0 ?0 ^% R
  grid-x-inc               ;; the amount of patches in between two roads in the x direction
, z2 K. |9 q/ C! R4 P( Z  grid-y-inc               ;; the amount of patches in between two roads in the y direction# R8 j8 I7 B: f; U+ u1 G
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
9 ^; ^: H$ N- k" `; y$ Q+ q                           ;; it is to accelerate or decelerate
1 v  S& Z  i* U% S+ B  phase                    ;; keeps track of the phase
' l* h2 m" J3 ?/ p0 x  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
( X' C) y) C" X3 `  current-light            ;; the currently selected light
, t' A9 O8 V8 _
9 Y7 u+ [( ]: P) Q& ~  q5 H" R  ;; patch agentsets+ j# T4 v: @, v1 m9 ^1 T
  intersections ;; agentset containing the patches that are intersections7 y  M* j  M1 Q6 h9 z- T% `) S
  roads         ;; agentset containing the patches that are roads
# D! E3 W9 C1 }]' U7 Z6 l( M6 H, J# M! N

1 W2 i$ r& Z! F; H1 F) u0 V* sturtles-own5 n5 e) C/ v" ?8 `; q3 x: N! F( f
[
0 F9 U1 Y1 ?- v# p( o) Z  speed     ;; the speed of the turtle, q- x8 g& g. \; Z4 J
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
* u$ u6 V" d; j5 O- N0 p8 }. l  wait-time ;; the amount of time since the last time a turtle has moved3 k7 |$ N9 W) Y* h- @$ S1 y
]
1 ^. f$ ]9 z: f  H6 r' ^
/ B. b$ E; M2 K  C# G6 X6 P* ^patches-own
1 H! |( D1 [! O' x. W$ J) U, T[1 a5 _2 f; {) {! a% r4 E2 ^
  intersection?   ;; true if the patch is at the intersection of two roads# B% ?( i3 m0 I. K$ T/ G
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.- R% q% y# \1 @" J; m- p* Q
                  ;; false for a non-intersection patches.! x- h' y. y. ~4 A/ M" T
  my-row          ;; the row of the intersection counting from the upper left corner of the
: x/ R, S& F+ O; c9 y0 s$ g/ ]; b                  ;; world.  -1 for non-intersection patches.; F, n- t$ `3 S/ e. x
  my-column       ;; the column of the intersection counting from the upper left corner of the
$ p, R* q$ Y/ S. c' y7 z& d                  ;; world.  -1 for non-intersection patches.9 _4 Y( s! u' _* g, X) V
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
/ [" p2 R6 F2 I$ c  auto?           ;; whether or not this intersection will switch automatically., `# Y  ~$ M* F1 e! k5 m
                  ;; false for non-intersection patches.7 F  u1 P6 U) a
]6 Y" D% {$ d& f6 B/ x) V+ j

* d. R: S3 l2 U, y% S+ ~- ~  @* y, z' h8 |3 S
;;;;;;;;;;;;;;;;;;;;;;
8 u! v% n6 h+ @# W8 b/ g: u# G2 [+ j;; Setup Procedures ;;2 l* ?' ]5 Q  h& t# G% L
;;;;;;;;;;;;;;;;;;;;;;
+ G; ~# t& W/ W. M- w! h
4 K' D4 K" U. ]: x# u) V+ M;; Initialize the display by giving the global and patch variables initial values.
; O3 c% V! l3 _7 m, A9 V;; Create num-cars of turtles if there are enough road patches for one turtle to
5 ^8 C1 d+ o" O' k;; be created per road patch. Set up the plots.$ K0 F5 B  B% ?5 R9 I! b
to setup
, h$ B) p# `+ @3 ^  ca
  c% A) Y2 j7 e8 D  setup-globals8 t: H2 d0 }# H$ U( v1 ]

0 j' w4 [+ r# k! Q( Y" R6 J  ;; First we ask the patches to draw themselves and set up a few variables( s, K1 f" \6 b6 D; m3 [
  setup-patches
4 U* Q/ x, @; s0 Y, z  make-current one-of intersections/ s' p6 D0 w7 B7 }
  label-current
: R; g5 }* U$ y
: b8 k" q2 \! B2 l" y; i" k; j" J  set-default-shape turtles "car"
" r  m  k8 f/ S5 j* C) H- G. {: Z0 \' j
  if (num-cars > count roads)7 p! S: v4 ]+ \6 X" `1 [. c! r
  [
9 @5 n: h4 R* S$ a2 [* D    user-message (word "There are too many cars for the amount of "5 r" Y, k" j7 n* |1 D
                       "road.  Either increase the amount of roads "
  ^8 X* E; m& F+ p) m2 r2 L4 L                       "by increasing the GRID-SIZE-X or "4 e; Z, [7 A9 |6 n, I
                       "GRID-SIZE-Y sliders, or decrease the "# O' }! H+ j2 ?2 w! S$ n% `
                       "number of cars by lowering the NUMBER slider.\n"
& B: v4 \$ Z; b% U, A. y                       "The setup has stopped.")' X2 {! O% i6 Z8 p
    stop" c) w; U! {7 w* Q- n1 n" E# G
  ]7 n0 J! Q9 r  B) R; Z- y

0 o; T! W$ L4 Z; N  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 t1 c; [& n  e
  crt num-cars
; [) a6 J; Y, |( J. c# Y6 C  [
! W; k3 X1 v* y' B( M+ A    setup-cars
' {' u, l6 C! ~4 G5 m+ h/ C( H- A- a    set-car-color6 U8 P2 i! M- b" J+ a
    record-data0 l) Q1 m: \( q; E5 H, j
  ]+ Y! I% O5 u) R
$ [" ?$ A! H- G7 f5 L( V5 ]( x6 F% _
  ;; give the turtles an initial speed
2 ^, e$ x3 Y( a! b$ V  ask turtles [ set-car-speed ]
8 Y: R: d- A/ Z" G
3 t' m0 w8 N% ?; j8 [( e  reset-ticks
$ `! F4 e7 X; Z; O: |% ^( [  Q6 pend
. Y" n7 w! t, G  m! N7 W: P' p! O* ~
, _+ h2 d* w: ]. @, b0 l;; Initialize the global variables to appropriate values
  L8 f/ i; i& X* U, i& d" Ato setup-globals+ j) _' ~  J" H8 B' c$ `
  set current-light nobody ;; just for now, since there are no lights yet! p4 f5 f5 _1 |
  set phase 0
, c+ ~/ K4 y( m2 _2 }; D  set num-cars-stopped 0
; ?' _( H! ?# m1 m: O% @& \  set grid-x-inc world-width / grid-size-x7 u9 F- X2 N6 k0 f1 L( L* u2 |8 P
  set grid-y-inc world-height / grid-size-y
: b. W/ y, w1 v3 U, k$ n  B. b% y" }8 S, s) S1 i( \4 h+ t* \
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" J- f: d$ K+ R8 X% y9 u7 A: j  set acceleration 0.099
0 o& g% P) F+ X+ b( L& M: Xend. Q$ ]! d, i* Z$ ~% O9 t5 A

+ X1 j+ U0 n9 v;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ a. X2 x8 T, b, x: I# I9 m" k
;; and initialize the traffic lights to one setting
/ B1 W( H# x7 H' D  {+ K9 nto setup-patches0 |) Y6 C  p$ a8 z8 ]
  ;; initialize the patch-owned variables and color the patches to a base-color
  T) y0 M+ Z7 W5 E6 a, c5 s8 ?5 f& W) L  ask patches
; P5 d" g) R/ t5 h  [
! C, I$ r: u! p0 F4 l% _    set intersection? false8 |: j+ f) o, X6 R& ^5 p- f' j
    set auto? false
: f! p, n0 s9 v/ H* T    set green-light-up? true3 D+ e9 k$ V1 O; {* R
    set my-row -1# V1 w; Z: g" ~
    set my-column -1
+ `1 k! n5 H- T5 O- q" a# |+ J    set my-phase -1
3 U2 n4 v( G" A& D6 X0 c    set pcolor brown + 3) b5 b( r" m+ ?. e! T
  ]
9 O) ?9 P6 M; s3 m( y2 t8 R9 E/ d& }4 E8 O6 x% }- v
  ;; initialize the global variables that hold patch agentsets* q' l/ H! @5 ?2 y8 Q$ p) ^0 I$ r0 A
  set roads patches with# G" D" R6 \2 o& ]/ C# \! Y6 E' s* \' n
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 j9 L2 J' k& y    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. E2 a) f% \% l% w/ ]6 d1 D" ]. v8 K' h; N
  set intersections roads with
0 e- C" N* M* h' c0 M3 ?- U    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 Z1 f, S7 D9 f/ H* K+ f    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# X  u5 w5 t' G3 T
3 n8 }2 P+ ]" R& M. g+ E: x$ U  ask roads [ set pcolor white ]  R1 F0 o1 ]2 i
    setup-intersections. |6 R$ A3 S# k/ `7 A
end1 f; t% s' ]$ `5 k
其中定义道路的句子,如下所示,是什么意思啊?6 o8 ?. r( c, V! w5 ]8 L; r- B! U
set roads patches with0 s3 u) y/ x6 r6 ?6 g6 J
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 D2 O& k  s0 y+ L, i6 C' e    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) N4 P" {' y) }4 t. h, [* Q. r9 F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, 2025-12-1 16:49 , Processed in 0.024375 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