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: 7438|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& M4 s" `( Jnetlogo自带的social science--traffic grid这一例子当中,
) B; S0 [& J8 eglobals8 s9 b" q4 Z' j
[
. @& D" N7 [/ d# x  grid-x-inc               ;; the amount of patches in between two roads in the x direction
7 W$ h, U4 z; z; _5 l  grid-y-inc               ;; the amount of patches in between two roads in the y direction
) ?0 j/ f, t7 z) T  q$ t" e4 @  acceleration             ;; the constant that controls how much a car speeds up or slows down by if( k5 v4 N7 z: W3 Q$ B: W  L
                           ;; it is to accelerate or decelerate) T+ Z/ _3 h+ ]; X) m
  phase                    ;; keeps track of the phase
% h- E% C  O% k4 D2 \$ _' z  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
+ {" \+ Q# y% {3 O/ X  current-light            ;; the currently selected light5 Y' K& f+ b  U) U8 t

4 v' Y, g1 B) C  c# J  ;; patch agentsets
+ f6 o3 A, z" P, V2 z/ F6 v  intersections ;; agentset containing the patches that are intersections  e7 N! N0 G; r
  roads         ;; agentset containing the patches that are roads
- \* r3 @3 U& ~& E/ T7 F]
0 \/ g" K4 E* b# z+ {( z3 M& V+ `0 R% t7 e* K  u) r
turtles-own- f, t$ ]0 X+ a2 y$ _
[/ {) c8 T6 v# j0 y$ a
  speed     ;; the speed of the turtle
9 g( Z3 p' m; K' Q8 a, u  up-car?   ;; true if the turtle moves downwards and false if it moves to the right4 j5 G5 _* @7 q1 E/ N
  wait-time ;; the amount of time since the last time a turtle has moved
) K: i( c( U. u" L- ]]
# Y) H/ Y+ a8 Q8 b, y4 j6 f" ^: N+ S" ]# q# J
patches-own
5 X* _) U- ^/ F* x+ `[
( W9 y3 w" d7 Q0 E2 [! V  intersection?   ;; true if the patch is at the intersection of two roads
5 V( a! i# A# i, |# K' t  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.: I+ @% b6 O& X$ B  A" L
                  ;; false for a non-intersection patches.  I6 Y# W% ]7 ]0 r. V7 w
  my-row          ;; the row of the intersection counting from the upper left corner of the6 s0 Q; o: I) ?4 [3 I
                  ;; world.  -1 for non-intersection patches.0 S6 p! F& f& o/ G4 q& w& C! A
  my-column       ;; the column of the intersection counting from the upper left corner of the
  u: q/ @( i: [                  ;; world.  -1 for non-intersection patches.
) A: w1 }( _4 C3 c5 |  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.; K  q( S- Y' t" @) ?/ M
  auto?           ;; whether or not this intersection will switch automatically.
$ L; y9 W1 ]) u# H( p                  ;; false for non-intersection patches.
- {9 W2 I$ O2 q7 Q& ?$ G, X9 H]. k6 ]8 n/ k/ q* N

+ m9 ]  J$ P6 A, `- G5 p( K* p7 E3 u' P8 C/ D+ B' x
;;;;;;;;;;;;;;;;;;;;;;
( @5 W6 y* M' A& y0 C0 `' m;; Setup Procedures ;;
, L# _* h% v( O; j# A+ b6 Q;;;;;;;;;;;;;;;;;;;;;;
. \8 j3 ]% y, x0 M4 F' z
  \) s# c- o/ Q+ M4 j;; Initialize the display by giving the global and patch variables initial values.
; l5 \, b6 D% |. U;; Create num-cars of turtles if there are enough road patches for one turtle to( e5 T  ?- q# C. B
;; be created per road patch. Set up the plots., L% Q' [# j3 N2 C6 `& a
to setup/ Y! E* _" q" r7 ~2 X
  ca; y9 m1 @, k% N
  setup-globals9 a( }$ q8 o. {; {8 U

8 U& F$ g, w, E' Q& e  ;; First we ask the patches to draw themselves and set up a few variables
" q! `2 I/ s# a; G9 f  setup-patches" h' N! k; v; {. [8 u
  make-current one-of intersections
; k( {/ A4 F( G: ]+ _( W6 [! V8 t  label-current% H7 B. A  s0 X6 {' E* \% t
3 k5 H# L" @* C0 D, p
  set-default-shape turtles "car"
+ b) r' _: C7 a. M+ A3 D8 j$ _% Y. E& w4 }" z' |
  if (num-cars > count roads)
0 g. _* `4 _) k7 B  ^  [
* c2 k( k: `) t' T, ~- h* u; R    user-message (word "There are too many cars for the amount of ", ~2 ?: b- f# c3 e8 g( I
                       "road.  Either increase the amount of roads "/ L/ y& G4 f4 w
                       "by increasing the GRID-SIZE-X or "  ?8 J5 M6 ~4 j7 I% Z- ?
                       "GRID-SIZE-Y sliders, or decrease the "9 u% [  m# T/ r! i8 u6 z+ S( t
                       "number of cars by lowering the NUMBER slider.\n"$ W& _1 t1 y8 M  ~/ r2 {  [! n" H, p
                       "The setup has stopped.")4 P7 W9 |, Y5 [- S; N
    stop
4 m' R/ |$ a5 ^  ]# m. C8 z( `( x' x1 T2 `. d/ y* x

4 i6 ^7 I; F; g  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 M4 v1 ~/ j$ H1 ^2 @
  crt num-cars
! W1 L! v* ]1 j  [; ]* ?; O8 @2 n: b% t# H
    setup-cars
! O5 A0 A# q, \4 Y7 A    set-car-color
0 a% l8 H4 H' h$ T8 l5 G    record-data, @( q5 P! y3 C% {( Y! d2 {
  ]
9 V3 x% W% O- O4 {
0 s: p$ ]/ t" U6 K0 h2 F& v  ;; give the turtles an initial speed2 f; \; t3 [- x; b  R$ j7 {
  ask turtles [ set-car-speed ]
+ a8 [+ u4 h! V1 J! ?# p; E9 S: J/ C) ~4 h! g2 ^
  reset-ticks
2 m  C( q) A2 V, B! iend
/ S. k* B. m9 }( X' E
2 h3 r" @' a! d; P) r8 [( I;; Initialize the global variables to appropriate values6 I) f$ k2 I5 G1 _+ A
to setup-globals& E$ U, A; a9 S
  set current-light nobody ;; just for now, since there are no lights yet% i& v6 A% I% k0 n2 x( f" s
  set phase 08 {2 u- F% S- u! S( \$ \# Q! ^; U, ?
  set num-cars-stopped 07 u, x  v3 T* B
  set grid-x-inc world-width / grid-size-x
. N3 T2 |1 v- T& |% Q6 o* ]: Y  set grid-y-inc world-height / grid-size-y
7 o; {' M) ?) w0 ?! d' n, B& u' t& g
6 `  F& T5 V# z7 h- v: |* M  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- n# H! I2 J( G( [0 |$ V! K( A
  set acceleration 0.099
$ [5 r! c! {- Y1 C$ q/ kend
, @* h: n& {6 j9 o3 f% O
2 F9 f! L, g/ R/ V! r  d% m9 w$ z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, O! M( e1 b, ]! S3 s# q# ?: \
;; and initialize the traffic lights to one setting7 ?- g9 ~3 f# _0 z8 p: e
to setup-patches
1 v7 M7 M& {1 g  ;; initialize the patch-owned variables and color the patches to a base-color
" P3 L/ g3 g5 \& k; l  ask patches  {  _$ k: ^3 Z, d# C, T- p# K7 Y" C) ?
  [5 ^7 Y+ d' c0 Z: {1 G$ E( I( {7 b
    set intersection? false
$ g& I) r! a. r    set auto? false
! x6 {1 B5 F8 o) U7 Y. x& h    set green-light-up? true! T( Z) N5 E  R, D8 M% Z* g5 U1 v) }
    set my-row -1
4 n: l$ p- H( C; H    set my-column -1
. w! r/ `. H" P) X3 Y  z  j    set my-phase -1
' C9 M1 i0 @& |! q3 v" K- M    set pcolor brown + 3
+ I" Q8 \8 l3 D2 }% S  ]/ [+ V$ w8 Q6 {6 g( D4 A4 f7 [

3 @1 X8 q. O: d( J  ;; initialize the global variables that hold patch agentsets
% b9 ^7 R9 G0 @2 a" G: p  set roads patches with
6 |, a; o" h6 k% E, H2 T8 ?    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ u0 ^, c. x6 L' \; m4 l    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ a' E& V4 n# ]) `# Q7 y  set intersections roads with
. j: b- d8 Y, X7 N* |( B6 D    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 B, s( Z3 l* c; |
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! G* h7 d5 g# W8 z
* g% W0 N0 }, L, ?  ask roads [ set pcolor white ], Y3 r- C% d/ @" ^$ B: Z7 `  n
    setup-intersections
# c; s( G* `0 n% I) |; f$ nend3 @/ |$ r6 M" ~" J# j5 ?! h) U3 m
其中定义道路的句子,如下所示,是什么意思啊?! D& o7 Q3 u- }5 X8 v$ z) J
set roads patches with( p% Z1 O( q& ?! q1 n! n; Z- e
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ [; i! `, t8 D2 ]    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( J5 N3 Y& O9 A+ g3 B: v7 Q- J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, 2025-12-15 04:50 , Processed in 0.013274 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