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: 9150|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。
# V! q+ [0 T0 |$ l2 b4 tnetlogo自带的social science--traffic grid这一例子当中,3 \- R1 O3 |9 u; X; r
globals
0 I) B4 U, W# g/ p( b% T) q( y- k[7 p& k3 c1 h$ i4 M, b$ u: K4 a
  grid-x-inc               ;; the amount of patches in between two roads in the x direction5 j% f4 P  l5 n# X  B: ~
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
8 a2 A' }# Z4 [  [+ M( N6 Y  N5 `  acceleration             ;; the constant that controls how much a car speeds up or slows down by if& f+ F3 g7 u. h9 z) Y: _5 R
                           ;; it is to accelerate or decelerate
1 k- t1 r5 A, w& E  phase                    ;; keeps track of the phase; f) g! m0 A6 o8 V6 U  m
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
0 A. y$ U9 z* c/ @; [0 M  current-light            ;; the currently selected light
( d2 E9 J3 i/ o1 V( Z2 M6 L
1 p/ d; |1 I" H! D  l1 M  ;; patch agentsets
9 G% b, T) W; |( r8 I) J  intersections ;; agentset containing the patches that are intersections
. [9 `! A( u, I' n0 Q  roads         ;; agentset containing the patches that are roads* p6 m; E& h. k% K
]. \7 i! [8 f! m: g- P. Z) \
  I6 q4 a. u5 ]* s/ m9 V
turtles-own
3 E" ]8 ^5 s% G% I( A[% H) _& w4 t, p
  speed     ;; the speed of the turtle& ^$ R' o4 z1 S8 ^, ]
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right$ J* N  `3 @* n) E
  wait-time ;; the amount of time since the last time a turtle has moved
4 E" F0 N! |/ u% X, E. L]
* J- _- C' f; K& d$ e; ~8 N/ s
0 G& B, B! y( ?6 upatches-own! `4 R6 u  L2 ^7 g  C
[, P9 ~& S4 K$ y8 h2 P9 @& x  B+ X
  intersection?   ;; true if the patch is at the intersection of two roads
( O0 ]" [, m" a6 f, q5 Q: k  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.3 ~( l3 A  J2 E' X& `+ W. P4 `
                  ;; false for a non-intersection patches.
  t9 C7 N7 _9 _' }) s1 w2 o  my-row          ;; the row of the intersection counting from the upper left corner of the- J* \$ W; K; f% q; x* z' @
                  ;; world.  -1 for non-intersection patches.
' N  J/ F. c6 P; Z' C+ p5 o  my-column       ;; the column of the intersection counting from the upper left corner of the, ?% c+ M1 q( L- Y1 r# T1 S
                  ;; world.  -1 for non-intersection patches.
& y0 a; a& g/ b1 [9 t  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
9 M/ T- W% m. m( v1 B  auto?           ;; whether or not this intersection will switch automatically.
8 }4 }5 A6 w% F# G7 E3 i* m. m) k                  ;; false for non-intersection patches.
& Q/ X9 b7 w4 F6 s: K7 {" Q]
1 `' J  r4 R0 L- @( j; s8 i/ ^) z% J9 L2 B% u/ A6 H/ Z/ D
* |; w/ U5 q# v4 v
;;;;;;;;;;;;;;;;;;;;;;
! R' E) g8 L* f: j;; Setup Procedures ;;
! N' w% g+ T% [6 m, }( u;;;;;;;;;;;;;;;;;;;;;;
" e! ?3 T1 a, v) V2 v6 F1 D- `7 j( N5 V: N  r
;; Initialize the display by giving the global and patch variables initial values.! g) v1 m! v5 n* g9 w2 y; q
;; Create num-cars of turtles if there are enough road patches for one turtle to
9 g$ ^& P* c* X& y* i3 s1 J0 i;; be created per road patch. Set up the plots.* S) J- O; Z+ C% u; n) u
to setup
( S. v6 d- g# t  ca7 B" i* e' z6 P( ?. ?7 ~* I$ X
  setup-globals: |& J3 m0 }$ j5 e4 R

& _7 b3 w  r4 U1 b* N2 l  ;; First we ask the patches to draw themselves and set up a few variables0 C6 ^( P* ?9 N2 D: C) L. P
  setup-patches
3 G9 n: c; a/ M4 A. E, q4 \9 Y  make-current one-of intersections
5 h) [, I* P2 z& s  label-current5 p. g/ J9 L, L
, s  X( j5 A& S; A5 e" ~
  set-default-shape turtles "car"2 t1 S" d! g& _. C" F
. W8 H+ |% H* m) R8 O
  if (num-cars > count roads)" C' j0 |8 z$ B2 Q2 p. J5 d
  [: L# }) m6 ]9 O: h
    user-message (word "There are too many cars for the amount of "
/ f. ~( ]+ Y4 o                       "road.  Either increase the amount of roads "
( l/ v+ T& @* V                       "by increasing the GRID-SIZE-X or "$ W) Q9 X6 n: M  y- v' L; W
                       "GRID-SIZE-Y sliders, or decrease the ". ]# r. X- S, `5 ^5 b, Y
                       "number of cars by lowering the NUMBER slider.\n"
9 Y9 L; E9 |! O/ ~                       "The setup has stopped.")
! I9 i# i/ c/ |! ^    stop
* g1 ^* a$ }* }8 B+ u7 b4 E* F; {  ]" h: ~6 f) ~" h' ?" y; V

9 }% T  _6 X$ g# `$ i2 ^  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color  {; G' x% m9 Z; c5 X+ k9 n
  crt num-cars
( m4 H6 n0 P2 _7 u5 ]  [
8 d6 p+ W4 p/ m: g" S    setup-cars
7 p  @* @, z" W% e  P    set-car-color, o* ?  E' j+ R- \; o* ?7 K
    record-data
: d. W- _7 W6 e6 R6 P7 Y% @: v  ]
0 i* o, |. U4 i0 f) N' U3 [' y. u4 p6 n
  ;; give the turtles an initial speed5 Z: m7 O1 p6 J0 l8 {
  ask turtles [ set-car-speed ]! a) ?  k  j& N5 B. B. _
: x/ |7 X0 B7 w, R
  reset-ticks
1 Z, y# p5 u4 k% _5 Mend
; R( K; N/ z- [& c
) g4 Z) R. G1 r' D+ O# C' H  J;; Initialize the global variables to appropriate values& f6 ?% V. S1 y! R$ K: y! c
to setup-globals
' j- q9 w* y3 K4 T/ k9 J) i  set current-light nobody ;; just for now, since there are no lights yet7 S7 l  Y# {, I
  set phase 0' D1 y$ d2 J3 O; |$ R+ P
  set num-cars-stopped 0
: c- V, l7 ?: u$ U5 q5 ^; i  set grid-x-inc world-width / grid-size-x
* r) K" v  q( `% h  set grid-y-inc world-height / grid-size-y
) {9 E, u; Q) g4 i2 {& i+ I1 M% b3 [- o6 a' S5 N
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ e3 y2 D! G" C9 R8 q5 o5 G
  set acceleration 0.099
, k& Q4 l" J3 oend* e1 L" P! ^! Z) _% `$ M
& T. B0 @# T  n5 _: m2 e
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% [, e) f+ m. |& l: G;; and initialize the traffic lights to one setting6 t$ H- C8 T* h2 K
to setup-patches
8 W1 Z6 p5 j/ k7 T' H; Z  ;; initialize the patch-owned variables and color the patches to a base-color; k  L& [: t& ^) u! p4 V
  ask patches
% c, e0 h7 B6 D2 K" D  [) ~4 z) B/ Y; G8 [- O  j2 L
    set intersection? false& z, P  ]2 Y+ ^) I: a) o
    set auto? false
4 \0 _. w: Y0 S9 Z% a) x    set green-light-up? true( f8 H' F2 J! w9 M9 V
    set my-row -1. }: U9 J+ @. s  g) c) M! m
    set my-column -1
$ [+ s+ H5 P7 s2 b3 K( F+ \    set my-phase -1% ^- x/ e6 j) e
    set pcolor brown + 3
* i8 x. Y: W4 q8 I6 ?# b, y  ]
$ m! M( j$ J# T  j
$ r; X2 u) f) Y! d- L0 |  ;; initialize the global variables that hold patch agentsets
# q  T2 r  Y3 J- v" m$ U  set roads patches with
" a# F- m9 D' o/ H( o: I. S% _    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ `  d" q3 b% c+ S  M# A
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ T; s) O4 q9 H( ?6 c! C9 V
  set intersections roads with# d3 Q7 b5 Z; u8 U7 T% q! ^  {6 j
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% s5 y: R7 {+ m. h0 k$ R    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 f. ^4 _2 @, v( `7 s0 J) z
6 l8 A8 Q* _/ R) C
  ask roads [ set pcolor white ]
3 T% k7 g. u) W/ [; G% ^& j. H    setup-intersections. ^" a3 x/ n7 G6 w6 z
end/ [4 q5 U6 {( _" s6 s/ s  ~9 T
其中定义道路的句子,如下所示,是什么意思啊?/ V9 t- C* a& {0 ]
set roads patches with
. g# a8 {* a/ c" T, |6 u6 i; q8 [    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% r; \! J4 ~8 s' D5 M! J, D- d0 j
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! y) T9 ^- B* h6 l; u! a+ _' 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, 2026-3-31 05:28 , Processed in 0.014229 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