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: 11878|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。1 E+ {6 F5 D; g/ h1 T7 }
netlogo自带的social science--traffic grid这一例子当中,
4 S$ u5 v# k; t# u) N# a0 ~( Qglobals2 q# r1 I  }4 @. i1 s- |+ m
[
0 v* v  V8 u# h9 W' R  u  grid-x-inc               ;; the amount of patches in between two roads in the x direction3 U7 d! s2 a, q1 G  h; U6 |
  grid-y-inc               ;; the amount of patches in between two roads in the y direction# x* M3 \; g% k; [; z
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
. Z. i1 m0 D' R                           ;; it is to accelerate or decelerate: u0 E9 F% D7 w" o
  phase                    ;; keeps track of the phase
0 N8 \7 O& e  g2 F% w( p  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
5 O0 M5 W# E: I  current-light            ;; the currently selected light" H! D6 ~3 P! [; i6 {
/ T& @' e; q8 V* R6 Q: F7 Z
  ;; patch agentsets
. B+ P" X' c, D, U) N3 ?  intersections ;; agentset containing the patches that are intersections
0 U3 j# q: U  e: Y. t/ _  roads         ;; agentset containing the patches that are roads% @9 y8 k; a2 x# S" S
]
( O# k2 _% M) R( b% a( D; r/ |
3 X) p& z8 Z8 {- B+ ~  i$ W+ Lturtles-own: a1 o$ f' f( i! l5 V
[
8 j, B8 R$ z- l2 S- y  speed     ;; the speed of the turtle
. t2 v5 ]3 R% s5 Q# D3 N5 k. D  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
$ Z; G6 \2 h. X5 i) }  wait-time ;; the amount of time since the last time a turtle has moved6 x; t; B/ z9 ?2 r6 g
]
' {/ x* U  ~- L5 p. U; R! [& y9 ^( [9 Q6 `1 M4 t; I
patches-own
6 O/ M7 I+ A9 O, e[
- O0 }* R2 l5 H# s' y  intersection?   ;; true if the patch is at the intersection of two roads
& U4 k- @7 c0 [' [  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.% f, S5 R- M6 @+ z; K% u
                  ;; false for a non-intersection patches.7 B, a% M& `# ~+ ^% y
  my-row          ;; the row of the intersection counting from the upper left corner of the
+ D8 `, O  b  r* _& J7 K                  ;; world.  -1 for non-intersection patches.) a, i. T. |. c8 E$ `5 ~7 t1 i9 i' X
  my-column       ;; the column of the intersection counting from the upper left corner of the2 T5 I7 `7 ]2 f7 v3 |
                  ;; world.  -1 for non-intersection patches.
; A9 ?! ^/ N3 ]+ l2 y# a  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
" r' q- g: w; |1 b  auto?           ;; whether or not this intersection will switch automatically.
4 `% u+ ]/ Y3 w9 J' j                  ;; false for non-intersection patches.
9 m6 `4 d. n* S9 L+ _, g. `* s], x5 e( K7 z6 U' x' _& c

( L2 Y7 e2 q0 j  Q
7 @$ W% ?+ @1 S) v. G" [4 K;;;;;;;;;;;;;;;;;;;;;;
; ~/ @: ^+ ~% y;; Setup Procedures ;;
+ i0 j$ B+ w1 ]2 y;;;;;;;;;;;;;;;;;;;;;;6 b  f/ S, Y. J7 H
4 X% v  D2 U; u0 N
;; Initialize the display by giving the global and patch variables initial values.- Y* G  ~& j; B. V4 N* R
;; Create num-cars of turtles if there are enough road patches for one turtle to# v. Y4 G4 J, K
;; be created per road patch. Set up the plots.
6 L  U8 c  H4 Q+ d" J* [6 O; Ato setup
0 r$ ^6 p0 k$ U2 f& l4 O  ca
5 V+ |1 W1 j8 S: w2 j  setup-globals
7 O7 J+ f( W# J6 T( s
- }& _" p8 }, ^' @2 \# ~6 m! R  ;; First we ask the patches to draw themselves and set up a few variables
9 D7 M: e2 e5 Y4 r  setup-patches! d8 y+ |! }' ~0 h1 k3 c, Q; j
  make-current one-of intersections
% o: V7 L. l: b) U  label-current6 {3 h4 N+ G* }& ~

& S9 r7 V9 W0 }" y  }$ Z; _  set-default-shape turtles "car"
4 h+ B0 Z2 W$ q
# w: b) K/ k$ @9 h0 R- {  if (num-cars > count roads)' @4 u) F9 L1 s% C
  [* x9 c5 I+ F" ?3 ^
    user-message (word "There are too many cars for the amount of ". K5 ?  I; j0 N8 L# K* ]. w0 K
                       "road.  Either increase the amount of roads "
' N: b$ h' [0 E* B' m* X1 ]4 [                       "by increasing the GRID-SIZE-X or "
+ z8 }- b7 z5 p4 L                       "GRID-SIZE-Y sliders, or decrease the "9 F* X9 i& z- j, Q7 E  y
                       "number of cars by lowering the NUMBER slider.\n"
4 E  t6 Y6 |7 ~  V& S                       "The setup has stopped.")
* T, R: Z, @7 E8 g    stop
7 Z8 U: J  x; a1 x  ]
9 k/ g1 W/ k2 g5 i0 V" @" F0 N
; {6 c4 k  E" G7 `' k  |6 U  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# ~* \, U  H2 l  F  crt num-cars: E! }3 y0 p; V8 o6 X8 v
  [
4 O7 d( j( k0 T( C) f4 p    setup-cars
9 l! C% b; o$ |6 d0 ~* A    set-car-color& R! O% g4 j, D0 ^  ^6 M
    record-data
& n% B  Z! t- p% w$ F  ]( I5 o" j& o: ^$ ]9 h) o8 \8 r
, c1 M7 c3 d+ z% |, ]
  ;; give the turtles an initial speed# S1 t5 ~1 Y  Z" Y
  ask turtles [ set-car-speed ]# a- M9 [4 Y, Q6 N0 \

/ l5 `0 j+ q5 G% `: f* _  reset-ticks
) S. G5 D+ [9 hend# V6 W1 M* n; u% B
, o$ g- B3 f0 R. S
;; Initialize the global variables to appropriate values" [. e6 l6 T+ f9 }
to setup-globals
2 x5 V7 ~, J2 r! T  set current-light nobody ;; just for now, since there are no lights yet
& _1 r& g7 e( k3 \  set phase 0. z3 n* H: ^' C" d+ P- g
  set num-cars-stopped 0
( ]! S) E" W) v  H% {" u" g: y  set grid-x-inc world-width / grid-size-x
  R  S; Y) E% a2 P  set grid-y-inc world-height / grid-size-y
1 O% ?& M1 @0 S! A. ?+ ~/ _9 w4 {2 Z/ r9 N7 C- `
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary+ L( F: e2 Z3 s& C7 F: R6 W
  set acceleration 0.099* `- S' v# k. {) e- f9 o( n% ]
end; d% |+ i1 z7 Q3 c
2 a3 A, S: g  T; ]
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 n1 v2 }$ V0 U- R* d& _;; and initialize the traffic lights to one setting
3 [7 a) j- a0 x- C0 }to setup-patches) ?( Y1 C1 |' o6 m9 N
  ;; initialize the patch-owned variables and color the patches to a base-color5 U2 A" f; y) `# U# i
  ask patches" \4 D7 I2 ^1 q
  [( \7 d  ~1 R* r
    set intersection? false
- |7 e3 s! w5 G9 X6 z    set auto? false
; E; y- G2 ^, ]: k# L* ^; W3 S! \4 o4 e    set green-light-up? true
0 L/ F2 p, m1 l! ?3 A    set my-row -18 H2 A. B2 T( x1 O6 {5 r
    set my-column -1
% u$ U' r0 A% x1 c: B    set my-phase -1
+ O1 K, M' k, N2 x" M. r* s' y    set pcolor brown + 3  z4 }( I- {$ O2 v0 b) E
  ]- q) y7 U6 K2 Z/ S3 e5 w
5 l) \. o' m& Q5 q
  ;; initialize the global variables that hold patch agentsets( O! G2 \& E  E( V$ A: i) z
  set roads patches with
5 W5 r0 Q" d) r8 X7 w* Y1 h: s2 |$ X    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 h3 z  p% `/ G4 F0 o  L( h/ Q3 M: a% E    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: U6 r8 b2 T3 n$ f9 J
  set intersections roads with) N; g5 v/ f( c" z% W
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* \$ e, U: E* r4 P/ Y3 F7 S
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 O& Q. I1 ^2 s/ V9 Z. }5 z
# z1 _; B9 G) s, B1 _! o. D2 {' m' x  ask roads [ set pcolor white ]
# \/ T3 G, \: M" X9 y+ P    setup-intersections- q( D" A2 s' _/ K) \* H* w
end
0 H; q" o* I2 |8 H其中定义道路的句子,如下所示,是什么意思啊?
5 v- p' o4 L- e3 P" I set roads patches with
1 {# e7 @# |" d0 u    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 b" L/ y% K, Q0 y/ _' y    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: E1 r# C; a  l1 c+ D( r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, 2026-8-22 09:49 , Processed in 0.020661 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