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: 9322|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。
3 ?$ L3 }( g3 L! o: @netlogo自带的social science--traffic grid这一例子当中,! z! z3 S1 h$ a# K; |/ \
globals7 Y* [, z* X. U; }0 E9 n
[
" y* l- Y$ k7 H# I9 ~6 S6 R  grid-x-inc               ;; the amount of patches in between two roads in the x direction
0 T5 W% h8 _( L, _2 h' m  grid-y-inc               ;; the amount of patches in between two roads in the y direction; C" Y4 n! [0 I& P7 O4 O' I
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
: d  J( g) Q5 k1 }" w6 Y" F                           ;; it is to accelerate or decelerate6 k  ~( r% n* P7 @0 X
  phase                    ;; keeps track of the phase
4 w* O" R2 n' A6 }  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure0 R$ G) R) t8 Z1 _! h7 I
  current-light            ;; the currently selected light& r& j  [5 }! Q; s

4 ?: I3 d$ j3 _7 ^' i  ;; patch agentsets' ?8 c& }& o( M4 u$ p
  intersections ;; agentset containing the patches that are intersections
) g  w4 k$ _: k$ S$ \$ S1 N1 @  roads         ;; agentset containing the patches that are roads8 L$ w( x( W% u2 g$ ?
]
% j; k( r2 q3 n7 a9 A6 h- f! p  F' W) j# h  p3 W
turtles-own
! g$ y* l5 r9 a( o[
' q/ h5 [' r: H- F0 U1 A$ L1 z! w  speed     ;; the speed of the turtle
; T5 M7 d* m5 C  Q1 G- u  up-car?   ;; true if the turtle moves downwards and false if it moves to the right$ A" K8 O! G/ y; O% Z/ k
  wait-time ;; the amount of time since the last time a turtle has moved
" o. @2 d0 i4 l7 t]8 d( V5 w6 L6 \4 `
* [) q1 ?3 k$ S! k1 |
patches-own
0 M8 _/ {- k% Q' z[
9 ~" H2 J4 n- y# J  d4 e7 X2 n5 \& S9 U  intersection?   ;; true if the patch is at the intersection of two roads$ M( R+ i) G9 M7 m1 T
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.( R5 n% A7 X# W; {; G! {; k- e& u
                  ;; false for a non-intersection patches.4 [3 f% v4 _7 X+ d; S
  my-row          ;; the row of the intersection counting from the upper left corner of the* N; s+ x) c; f! Z. e2 j/ |) V6 V2 q
                  ;; world.  -1 for non-intersection patches.% ], u' V/ l4 n# N8 k
  my-column       ;; the column of the intersection counting from the upper left corner of the
) y- D$ L- P  A6 d; u6 b9 }$ p, M                  ;; world.  -1 for non-intersection patches.
+ P( T, `* ?: X' ]0 Q( p2 W  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.* X" {  P. R& c
  auto?           ;; whether or not this intersection will switch automatically.* h- w$ B8 b* V6 `4 n
                  ;; false for non-intersection patches.0 K5 W+ @- Z1 Y- }- V8 L
]/ v+ i' j8 y9 p$ L3 l6 S

; Q' T  x! l) r7 c; ]3 z" C0 g; x$ I
;;;;;;;;;;;;;;;;;;;;;;
/ T4 {' }9 n* }- p5 m0 n" {9 q;; Setup Procedures ;;
5 l( s. c1 |6 ]+ e% N/ }5 P;;;;;;;;;;;;;;;;;;;;;;
7 t0 s; R2 U! H0 d1 t- Z; k6 K2 O, Z5 K+ a: N" P8 ]
;; Initialize the display by giving the global and patch variables initial values.5 ?4 J. ?8 S! G) `. X
;; Create num-cars of turtles if there are enough road patches for one turtle to% R+ e: y, E; N% K
;; be created per road patch. Set up the plots.8 R+ Z( f, k: h6 E' `
to setup! ]5 U% z' O8 h* x: y
  ca; K% Y, [; |5 m: b1 \
  setup-globals; F: q+ U1 j5 E$ N7 h
* |/ I4 L8 l4 r& E9 h
  ;; First we ask the patches to draw themselves and set up a few variables7 y2 k3 v, y9 ?; n
  setup-patches! _7 j# M5 ~1 R' [& t/ n
  make-current one-of intersections) V$ d. r0 ~& l1 \) U" A
  label-current
+ e8 ^- G9 b* }; ?; [9 n. l; G& n0 r+ F& u
  set-default-shape turtles "car"
! d5 c* k! Y& E5 }0 y; z$ A* g3 u1 K7 s/ p: b; h9 g8 c) ~
  if (num-cars > count roads)
* T6 M: z9 F8 i* I9 T% W2 c: X  [0 @6 f* E/ c* d* V/ k2 x& b. j
    user-message (word "There are too many cars for the amount of "2 h3 ^3 ?$ R$ u' K6 J1 E! R8 G/ M) [
                       "road.  Either increase the amount of roads ", S( F9 d* k0 d
                       "by increasing the GRID-SIZE-X or "6 g7 M* o9 C! i7 g" S7 W
                       "GRID-SIZE-Y sliders, or decrease the ") g: x; t0 r' t% O1 y9 s5 L0 w. P
                       "number of cars by lowering the NUMBER slider.\n"
) g6 X1 {: G; ^. j: o9 e, i2 b                       "The setup has stopped."); q$ v% Y8 ^9 v9 o$ {
    stop
. f  k4 M6 }- e5 k- W  ]( o, e  E7 L$ J* T4 f! i
$ n2 j3 x0 y9 R/ ~' h+ U
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
! J/ F" _" ^3 W# ]  crt num-cars
$ \( |; N; r& [! x$ H% @  [
* {" t! A% o" W2 ]$ D: e    setup-cars5 p0 j7 v7 x* K; Z" E3 v& A
    set-car-color6 s0 h. R: x# X3 O) f. C9 a
    record-data
. r3 Y  ]" O) y* J3 F  ]
/ V  [0 K7 A1 B6 r4 p( O$ o$ X( ?& Y& V" c' h* r. R* Q/ S, S
  ;; give the turtles an initial speed
- e* Z$ _5 G+ C  ask turtles [ set-car-speed ]
. `' ]- l2 q4 c
  ?- n( b9 s' K8 }  reset-ticks
5 ^5 k1 n1 \1 \3 Y" L; Gend
$ W2 |1 R/ s& m7 ]% M0 ^% F0 V* S' y- G5 s
;; Initialize the global variables to appropriate values
4 ]4 K& b4 f- F# H3 gto setup-globals
% s+ V6 ?+ A/ R/ d  set current-light nobody ;; just for now, since there are no lights yet( ~& g0 ^& Q1 |! }$ @4 d6 [
  set phase 0
, E" o; O) r) v0 O( n  set num-cars-stopped 0
! W0 D# s& E( P: G" d; I* a# T, D% I  set grid-x-inc world-width / grid-size-x
5 T6 e' T$ k3 o3 R1 n  set grid-y-inc world-height / grid-size-y, g$ ^( [6 |9 J4 R  d

4 v: Q. w5 c/ b5 ?4 w  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary  f3 p* H% A' M8 Q  }8 H
  set acceleration 0.099
3 F4 R& N2 [1 F* U3 nend
  J1 B6 {; K( v. p* u, ~6 v1 F6 m
( |! K) s1 z2 A6 Q$ _;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
! T& G9 ]% g; ?;; and initialize the traffic lights to one setting' ~/ S: W7 Y! i( d$ L( U2 E
to setup-patches" `+ e2 [1 Z" `; f0 }1 [
  ;; initialize the patch-owned variables and color the patches to a base-color( Y8 I! b6 G! ?& `0 K  c
  ask patches! E8 p. o+ c' q
  [8 F3 `* ]2 m2 M6 i4 o; R  d
    set intersection? false
$ v6 w1 p- ~7 X. h    set auto? false
- h+ @) `' I5 e$ [+ N    set green-light-up? true
, Y$ b* b# q5 E2 Q7 J0 f    set my-row -1, {" N, a* G2 O1 p0 b
    set my-column -1( V* Q% ~* R* g2 a
    set my-phase -1- _$ \: M6 Z$ d* `0 e! V( `' ~
    set pcolor brown + 36 ~/ s1 w) x( `8 I
  ]
  p' ]5 v" ]3 [" ?; c; a* Z$ R. r' R9 P3 ]1 ^
  ;; initialize the global variables that hold patch agentsets
9 P: }* {' \0 n" o* ?  set roads patches with  N2 ?! A: N; \& V8 B' _) I
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# R2 l9 D+ v6 z! T; P8 E/ h
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: J! \7 y; G  s3 i
  set intersections roads with
' b4 e  g. M* T7 p7 d: [( t' f' M    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ O  n; [7 R  U    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; Z7 B, {1 w5 x/ |/ e

9 V- a5 T2 y7 [  ask roads [ set pcolor white ]
, M% U5 h- Z% }7 N  C  c9 M# n    setup-intersections2 u# e, T0 c9 E* y; X4 `
end7 z. V& j% x, D9 I; i* |+ N* U
其中定义道路的句子,如下所示,是什么意思啊?& B- q& n3 R7 `' e8 [% n! p
set roads patches with
7 Z7 O8 Q& U% ]: [1 X/ M9 m5 a    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# d" h, k% |, ^" @3 I    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. X" p* ]" Y4 B9 {! M2 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, 2026-4-9 22:37 , Processed in 4.024813 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