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: 12017|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。
- i! u! ~9 |: V. ]3 Ynetlogo自带的social science--traffic grid这一例子当中,3 Z& |* ^$ v/ v8 M9 G2 F
globals9 i7 K" J9 n/ n+ D% X* D6 _; f
[; P  B2 G& N" n9 B( Q
  grid-x-inc               ;; the amount of patches in between two roads in the x direction0 C, N+ j+ P8 n. G' u( b% E' L
  grid-y-inc               ;; the amount of patches in between two roads in the y direction* {8 v* \9 w; Y4 G; \4 h) P8 c+ e
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
& ~0 d1 F& j, V' e1 i. H                           ;; it is to accelerate or decelerate
8 ]3 |# a/ p) F  phase                    ;; keeps track of the phase1 o9 a7 {( d0 z0 d: P5 i
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure9 {" c0 F6 K; \7 k8 j3 @
  current-light            ;; the currently selected light$ n1 [( F. z& S3 J8 W, v

! J0 B( Z, R0 _8 x0 t0 H  ;; patch agentsets
0 O2 g2 s3 q& v+ n  X! L: R  intersections ;; agentset containing the patches that are intersections" R) f* ^$ u$ ?6 {; c9 n
  roads         ;; agentset containing the patches that are roads+ V6 b# W+ O5 D1 g9 P; h- ]* K
]6 }1 @! {6 F* N8 |  w- z
+ l+ r' y  U0 O) d9 V4 i
turtles-own
- H) Q/ B, L  y. d- d* N8 c6 a* q: }[
0 B( \$ D' V- b" |8 I6 L  speed     ;; the speed of the turtle" o6 |- ^$ K8 q
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right3 ~% ^2 a% e. d9 e2 M$ g! x
  wait-time ;; the amount of time since the last time a turtle has moved
/ Q5 d" ^' O! f5 A; e: N3 n6 E]
9 \1 A  {( v) o4 M$ `* {( q; f9 r) r( G$ `- q
patches-own1 d9 j! {  z) P
[4 x2 L8 [9 C) c' f: |$ j; b/ L! U
  intersection?   ;; true if the patch is at the intersection of two roads3 ?! C) j8 q# Y1 l- ?
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.; K! e) W. s) |: f4 n
                  ;; false for a non-intersection patches.
6 M4 }) Q* f" @- ^/ g6 t4 s& {3 k! i5 R  my-row          ;; the row of the intersection counting from the upper left corner of the
/ s% R: x, T9 e; y" K                  ;; world.  -1 for non-intersection patches.+ n4 ]9 V- Y  u6 O
  my-column       ;; the column of the intersection counting from the upper left corner of the! @; C( G) ~, o
                  ;; world.  -1 for non-intersection patches.
' n0 d. D. R( s- R! g& k* K  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.  {5 r; L" s. ?: K+ K
  auto?           ;; whether or not this intersection will switch automatically.
* F  F( p  q6 g$ x( l; x                  ;; false for non-intersection patches.2 {, p& d, l6 w) M6 H
]
; D# C" t! [- q; Q& Y- R. f5 F8 a* z+ @( t1 A0 ~

5 x& w$ D) i8 k: W5 F' q;;;;;;;;;;;;;;;;;;;;;;6 P; A: Y) c6 v$ B; c* F2 {. m, t% @5 s
;; Setup Procedures ;;. B2 ]+ o+ g' F0 S$ L
;;;;;;;;;;;;;;;;;;;;;;
8 `/ L' j/ Y. ]) b5 `% J+ e2 n! u
;; Initialize the display by giving the global and patch variables initial values.0 w, h0 v1 a4 ~8 ]
;; Create num-cars of turtles if there are enough road patches for one turtle to7 g: |% Z8 Y9 C" n% Z6 h
;; be created per road patch. Set up the plots.: w+ G; e8 Y( |. _
to setup
+ [) Z: n' l0 f2 w, ]4 _1 c# w0 U  ca. u& m& b7 T' [- y$ g
  setup-globals' [% C( `8 i6 j, Q6 |/ z

2 \2 P& ]9 y. g+ L' I' [  ;; First we ask the patches to draw themselves and set up a few variables
: S) p9 c8 v, ?3 H4 j+ p' H" o  setup-patches' B( A+ e$ r* [" r& [
  make-current one-of intersections
& ]" g! y: w* N  F/ R8 K( R  label-current: F" N( H6 s6 w

; b3 E  A$ t! @9 Y. b  set-default-shape turtles "car"
/ t! G& x7 u1 ~: C5 r
% s& \' u' A$ d/ J4 L' G' W  if (num-cars > count roads)
/ j" M( s. ^$ s  V% M6 J  [
- }) O$ o% Z) T( P    user-message (word "There are too many cars for the amount of "
% [( L" e* [. t                       "road.  Either increase the amount of roads ", |. L% f& t3 J3 a
                       "by increasing the GRID-SIZE-X or "
5 p/ g3 X/ R* [' F                       "GRID-SIZE-Y sliders, or decrease the "+ ?/ i8 H$ c% v, z2 E
                       "number of cars by lowering the NUMBER slider.\n"
- Y9 g0 ]; Z5 F4 ]( h) O                       "The setup has stopped.")- s4 F# `9 `, ]9 }
    stop
8 |/ x, Z  f  G5 q  q  V4 _: S% X  ]" y- s$ N0 q. \" m
9 s1 @0 a& |% u; O: |3 q
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 X3 u9 L: H" ]
  crt num-cars
, y0 B+ }; ]: W$ a. i6 T4 H  [
) m$ a- d  B, y% z8 W2 `    setup-cars2 j4 s: l9 M0 ~5 x. c; U
    set-car-color
5 W2 h* ^% U8 b' s* _    record-data$ T7 J' X! G% R8 H" l
  ]
" V% {8 O5 y+ n) m: a$ P, |' u0 M+ |8 ~
  ;; give the turtles an initial speed
/ I8 S: q! r6 @7 R9 }) x  ask turtles [ set-car-speed ]
' q+ O+ i, U" z
2 k# _% O( X) f; G( n% s  reset-ticks
8 e; L' a+ _# |: o' i- C% g% f6 A/ f9 }end
" L3 Y; Z/ x3 b. f: P# ]1 q4 j7 i# i$ P
;; Initialize the global variables to appropriate values" i7 N6 F; X1 E* x) S' L
to setup-globals
5 Q) u4 @/ B/ Y: O, h; h" L  set current-light nobody ;; just for now, since there are no lights yet
0 K& W& r7 I, Q* d, f  set phase 0. E3 g8 }! E" k, e, {" Y7 M  ?
  set num-cars-stopped 0
- ?2 L. o* W$ {+ e: K5 i+ M  set grid-x-inc world-width / grid-size-x
! U' i7 a: Q/ i. Y( W- `( ^  set grid-y-inc world-height / grid-size-y+ i+ v! D& B+ S* X: G
# |$ N! u( w' p8 d1 L, Y$ R
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary1 d1 ~. R- L) {/ ?
  set acceleration 0.099
. M/ f8 A- y) X. T: }7 Kend
. g& o/ Y" O8 @' G% W9 y5 C+ j1 q5 A; j  Z) i5 _: `
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
  n0 W8 U* k) E( r;; and initialize the traffic lights to one setting5 M+ J& j7 y. P4 o+ d
to setup-patches- q3 Q5 w  Z/ q' z  m( ^
  ;; initialize the patch-owned variables and color the patches to a base-color7 j) d8 p; Y2 a4 H' N! w7 N
  ask patches
( \' q' z8 }' |) q( s; G  G; h! Q  [
/ s  F* ^, y8 S# o    set intersection? false5 U& D1 o- j  d: z
    set auto? false
1 Y, F/ F' R; W' c7 [7 b7 n) f    set green-light-up? true
4 t% s% p: _6 ^0 }9 B7 y1 B    set my-row -1* F: F$ k( J7 ~: p- I" m. }
    set my-column -1
0 N$ n  k0 O' n8 [    set my-phase -1+ N1 K3 t( ?+ F* r. `# v9 s9 R
    set pcolor brown + 3
) s9 `% J' c' @5 ~) D& c9 T+ C  ]* c( d) {) M7 h$ Y5 M9 h

/ A5 n. ?& p* S4 e4 o  ;; initialize the global variables that hold patch agentsets
8 \+ l/ i8 D8 ?$ r  set roads patches with$ I1 G+ X: M$ o9 e; ]9 l$ h1 d
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: f/ f0 L4 c9 l7 r
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 u- x# B& [4 P3 ?9 }5 q
  set intersections roads with
0 O; |8 d! i6 A0 s    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ q- R+ g" d7 t    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. |% ]- o4 U4 d, r% I/ c/ Q
& D/ P4 l1 G* l  ask roads [ set pcolor white ]) M, v# W2 o5 B5 _; h( v: G
    setup-intersections
- w# V  M8 M1 e1 B! Wend! F; t+ S$ H: U5 n
其中定义道路的句子,如下所示,是什么意思啊?
2 q! {1 o6 T) o- ~  D. U) s$ @ set roads patches with
) U+ f6 z: N  i) G2 x+ x/ S    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; C) E. @/ L+ m4 }    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 b" n# e$ I% Y" ]9 d) F* H1 l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, 2026-8-30 11:03 , Processed in 0.017163 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