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: 9113|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。# l% i3 B2 N; G  B
netlogo自带的social science--traffic grid这一例子当中,7 ?& e. r- \/ n* u
globals* Q9 Y* X8 U" Y  w! H
[
2 h! g) i6 A; j7 j& R7 o! |6 E4 {  grid-x-inc               ;; the amount of patches in between two roads in the x direction
8 ]8 W3 x4 R( k  grid-y-inc               ;; the amount of patches in between two roads in the y direction0 r7 r' a* _$ ^. V+ Z7 q( m
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if/ K- }% ]9 y7 T4 l# V7 ~' S" T
                           ;; it is to accelerate or decelerate
7 L4 n! C2 q& a3 k: }* w  phase                    ;; keeps track of the phase' p& R4 x+ z' D8 T! c  t6 F
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
* k: m' t$ q7 G  current-light            ;; the currently selected light5 ]8 ?4 _' a' b8 y5 c2 p% h
! F/ c) ?, n2 k% d$ z  W, }2 N& d7 i6 i
  ;; patch agentsets
, X4 _4 U( W* ?; g% ?: a  intersections ;; agentset containing the patches that are intersections' h6 w% U4 E0 W. ~- X- _7 |8 A
  roads         ;; agentset containing the patches that are roads
  Z: g& q0 F. l; `]
3 P5 \" ?, u+ }2 Z8 ~4 Z
$ T- r2 M. n. K8 \7 d2 J. [: lturtles-own
1 F( b$ z4 o% u, A% V( ~: c* B3 s[
. F+ O+ U% O4 U; j: `3 c1 {, |; k  speed     ;; the speed of the turtle
' R5 _. i8 W: D  B% C+ E. ?  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
& d% N! Y* n# q( Y; D4 r  wait-time ;; the amount of time since the last time a turtle has moved
% V2 S7 }3 T: F: S8 {! I]" R: o* `9 W# h2 q) I1 ~
& L. J( Q- z. M% \6 f. c* I
patches-own
$ _8 V- V8 `$ B7 s; k; S0 b! l[
( w1 h) I; x4 N. [  intersection?   ;; true if the patch is at the intersection of two roads
( ^5 [) y4 D- C  green-light-up? ;; true if the green light is above the intersection.  otherwise, false./ S, }3 Q8 m: X+ Q4 j
                  ;; false for a non-intersection patches.
+ t, d5 ]" V0 s% K& v  my-row          ;; the row of the intersection counting from the upper left corner of the9 |$ _! |$ ~* D
                  ;; world.  -1 for non-intersection patches.
' L$ e. T3 ~2 y3 S  my-column       ;; the column of the intersection counting from the upper left corner of the
: o! S0 \9 Y3 m& H8 c                  ;; world.  -1 for non-intersection patches.
& a! f9 Q) \5 f  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.5 P9 s. c& u1 F' |8 j3 ~/ \+ [# V
  auto?           ;; whether or not this intersection will switch automatically.
% }) K2 l2 ?) h/ X9 l1 v( N# `& O                  ;; false for non-intersection patches.
3 A: p" Y$ Y0 F! ?, D: G]
9 v, \" W# D( F- |( T/ z0 v9 ~2 S; D8 D+ t9 R) J) r
. {3 `* t" b: H* @( \9 y' u$ X. l
;;;;;;;;;;;;;;;;;;;;;;
/ M/ s; w7 @$ s9 ~' g" ?0 y;; Setup Procedures ;;
+ }) m3 V5 P$ I- b; w4 u% j, o;;;;;;;;;;;;;;;;;;;;;;1 E9 x3 g+ a$ |, R! S9 n; s  Z

! p# S5 h+ {# t! K: Z0 @;; Initialize the display by giving the global and patch variables initial values.2 ]$ j. o) `7 k& [, g8 X
;; Create num-cars of turtles if there are enough road patches for one turtle to, _" a4 J2 z9 d1 U
;; be created per road patch. Set up the plots.
- U" P* g. [7 O; z2 jto setup
) R3 d# `6 k# _3 n. l' W  ca6 z5 v  f! H- \1 R# I/ D6 }
  setup-globals
5 c, W( X% b9 q: j5 s8 B4 x0 o# ?8 y& S8 Y3 {
  ;; First we ask the patches to draw themselves and set up a few variables4 }0 [  \. W2 Y; s5 \
  setup-patches! ]% I3 y- \! L+ a
  make-current one-of intersections
) O, t$ K3 j) G" u+ m% O  label-current
/ ^/ T" b# B- B- @2 u# ~
7 Y* I- I& m$ g5 h& w! L7 T  set-default-shape turtles "car"
8 L! V2 b6 Z! A& D5 o: Q; ]) R5 `
  if (num-cars > count roads)' \! T, v( J- V/ e* t
  [
3 |; O/ O1 n( M    user-message (word "There are too many cars for the amount of "1 ]0 G5 h' B9 Z7 w0 w
                       "road.  Either increase the amount of roads "
' H- W) I% r6 M( F" Y3 X4 m5 Z7 M                       "by increasing the GRID-SIZE-X or "6 m2 V  b. H1 B  {! F9 u; d
                       "GRID-SIZE-Y sliders, or decrease the "0 k5 ?5 ^, q* t) G8 A
                       "number of cars by lowering the NUMBER slider.\n"
1 b+ ]( X) P3 }+ h1 K- H, c4 p) O                       "The setup has stopped.")
2 J/ B% h0 q" g8 Q& Z# a2 ]    stop
; }* e  l9 J6 g+ Z( J( w# M% C  ]* L5 }) `. n/ h/ f9 k
  ]. r% P% G8 h% x
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& H5 A" U# n% H, l/ V  crt num-cars0 T) m# L& {( e/ q2 t  v
  [
: X0 f0 `- B! E    setup-cars
) C  k" y/ i' Q8 ?, H    set-car-color
8 b6 Y- i) b5 V. E5 U3 {    record-data( E4 O1 _2 G, w
  ]
/ y4 l/ ^' ?% C4 g& V2 I
! W0 W3 d& ?% y3 L& v  ;; give the turtles an initial speed3 S% ^3 E% w. ~2 C/ `4 k8 ]4 F
  ask turtles [ set-car-speed ]5 c2 {/ U2 j3 g5 i, ^  A& G

8 p' l- A( p6 J; y( c4 n  reset-ticks
. ?8 h+ |4 N1 U  e3 d, W6 U5 `end8 E1 e3 l' M: T, m+ \( p3 r7 `" j0 @

7 O0 r" w, G& m+ k;; Initialize the global variables to appropriate values
2 M0 R' T- Z: T. `0 oto setup-globals
- a7 D- q0 A: W' A/ `5 ^% y  set current-light nobody ;; just for now, since there are no lights yet0 ~8 I5 e* Y4 C
  set phase 08 i/ S* g; w5 b* q- I7 _+ z# b& r
  set num-cars-stopped 0
- i% \" Z1 [, c/ m" k! S- B  set grid-x-inc world-width / grid-size-x3 T1 D) b: l6 J
  set grid-y-inc world-height / grid-size-y1 X2 G, f  }/ a7 X
9 G0 _+ I$ K) b0 [
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! F5 u' O! ?! V; t. B  set acceleration 0.099
: A3 d, y. c3 x( T% n$ B2 [0 h2 bend
! B/ P0 A" G& n" V- ]( G, G, P) q  H( `, U
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 j$ W0 Q2 \% `3 g( v5 S3 D' X! A
;; and initialize the traffic lights to one setting0 n1 a: x) L% v  j! V
to setup-patches7 G6 q+ T( w% A4 o; E; j6 K2 E; y
  ;; initialize the patch-owned variables and color the patches to a base-color6 t  H, q9 |* D5 @1 n& V
  ask patches
- O+ w$ z2 V$ Q  [
  f  C( I. Q4 z  E- A    set intersection? false
! {  q' Z8 e4 V) M) {    set auto? false  V2 ~+ S9 |/ y3 m* ?! ~8 q2 [
    set green-light-up? true$ Q" Q: Y1 d- W( M( e: Z
    set my-row -1
9 @$ V2 A' C) N- o    set my-column -1
% m0 {5 \( `: z* c. j    set my-phase -1
3 D' z4 M  i* Z* X3 ^    set pcolor brown + 31 x8 ]! C- R; `) L2 i
  ]
9 O2 S% r! K, r5 S( F, N! s
/ ]- V: |5 D, x' V  ;; initialize the global variables that hold patch agentsets, [! v" m4 C+ Z& D2 i
  set roads patches with, x9 m" N$ x* F& [& y3 C
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% M5 [- [9 h, }
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 E; F" T0 x7 h* ?# u! d0 `$ [, g" Z2 Y  set intersections roads with8 F0 q! @4 _! c7 D  k+ Y
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 R9 O  K' m9 [2 p  v( \/ u9 a1 Y    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 \; K. g( W  z" S% ?* _; M+ a

& W, A0 [! J" b  ask roads [ set pcolor white ]
( B# Z" N' a+ ~8 ~+ U: S3 \    setup-intersections$ x4 W! J+ p3 s+ X9 }
end' b" J( }/ o# _5 m
其中定义道路的句子,如下所示,是什么意思啊?  B8 U; e/ q' @4 V6 P
set roads patches with
& N) s$ e* o. g1 A) c8 T  g    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# o# u" m- Y4 v: A6 `' T& N
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 E3 D1 u# }" Z# h4 y! @
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, 2026-3-28 12:44 , Processed in 0.020268 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