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: 9522|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。
$ \. Z0 P- L* x8 _5 n- O- ~, g9 y( wnetlogo自带的social science--traffic grid这一例子当中,8 ]( N- d# X% c$ a; h
globals9 S5 R) v' Z8 b/ D
[$ W7 v* G  E. ]/ n/ v4 g
  grid-x-inc               ;; the amount of patches in between two roads in the x direction$ a! A# }2 x: n
  grid-y-inc               ;; the amount of patches in between two roads in the y direction
' \6 }* D3 Q2 F/ w2 ]2 O  acceleration             ;; the constant that controls how much a car speeds up or slows down by if7 w: M4 c! ?& h4 \3 W
                           ;; it is to accelerate or decelerate
- P0 F4 s# W3 z- F7 ~% _1 T  phase                    ;; keeps track of the phase7 ?8 ]& J+ T: ~* w' p1 P
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
5 p' U' F& ^1 h' p3 p0 z2 X  current-light            ;; the currently selected light
) K( }' [9 ?, M+ @( d/ s6 q4 V- v, ~2 d; @7 r# U! F! |8 a- Q# k" E) A# B
  ;; patch agentsets' G# v! a8 J' b. [. u
  intersections ;; agentset containing the patches that are intersections
7 R* s  y2 j! x  `/ M% q  {% L8 s  roads         ;; agentset containing the patches that are roads
4 N$ d3 {" W4 E" l$ x]
5 h* |9 ]! D6 m1 f3 ]! @5 [
: G6 {) x6 _. {* b/ V' @turtles-own% n, I, g, E' |
[4 |' I4 e! o1 i7 s7 Z/ ]3 z
  speed     ;; the speed of the turtle) K- [! y+ w4 I3 s- R0 p7 r8 _
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
" I9 i  T+ C. R% J; _7 Y) {- P  wait-time ;; the amount of time since the last time a turtle has moved, y8 T$ O. N# |
]
& N% z# d2 U% U) J4 c2 W4 I5 c$ i0 Q6 o2 f7 ^
patches-own
3 h9 _  w2 }, }# [1 R[2 ?4 b8 N$ D' [1 |, @1 ?
  intersection?   ;; true if the patch is at the intersection of two roads2 s: G) X7 W2 g2 J6 ~: E; n& K
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
, N' O7 {6 X: }9 x4 h6 k: Y9 i; a9 y/ S                  ;; false for a non-intersection patches.# x; m* H) D: A9 Z1 N% {7 p
  my-row          ;; the row of the intersection counting from the upper left corner of the1 I% Z3 o4 |1 l( t+ ^. ^1 m5 v
                  ;; world.  -1 for non-intersection patches.# `! U2 [8 y$ t& F( B+ x
  my-column       ;; the column of the intersection counting from the upper left corner of the/ b' L. k, Z+ o2 I& x
                  ;; world.  -1 for non-intersection patches.3 x0 a3 M7 |7 _* k) w  Q+ }
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.9 i. D- e& i' e+ x9 B# F1 P, B
  auto?           ;; whether or not this intersection will switch automatically.
. |) p% L9 R  c3 O. c                  ;; false for non-intersection patches.
2 _' g0 l3 v+ f% E" `]
( P! X5 j" `5 c" r* y3 l, k8 l" a$ F% n1 ^$ O) N! A. z

8 \6 d/ J# J& G. _: W; C;;;;;;;;;;;;;;;;;;;;;;
3 N: _& L5 \7 v0 L;; Setup Procedures ;;
5 x, l3 c' E, d! O. T;;;;;;;;;;;;;;;;;;;;;;
+ n: i! d) y- ~+ V
  P! a/ D# T5 Y' d( F! |2 M;; Initialize the display by giving the global and patch variables initial values.
% k/ c$ ^& y# c' Y;; Create num-cars of turtles if there are enough road patches for one turtle to0 h) m. v& X( g
;; be created per road patch. Set up the plots.
  |; |( V5 _- W& o- K2 c& F+ vto setup
: F7 x) M) M. T; D" z9 M  ca
; P( N2 S) q  S, W! d- `* c0 m+ n  setup-globals
$ j: {! W0 m; J% O$ ?( a. l# l
  ;; First we ask the patches to draw themselves and set up a few variables
4 _3 ]" |* c' B% x  setup-patches
2 O9 O9 t5 t6 U. F; b  make-current one-of intersections. p3 I+ B* j; q$ S" R7 ~; ?% p
  label-current2 Z# q4 B2 u- V& k1 b' E
' K5 |/ Y' h0 f! N. r# G, D3 e" g
  set-default-shape turtles "car"- A5 m. d, a2 r

( V6 U. @1 W5 [  if (num-cars > count roads)/ n1 E: _, n; j6 Z$ Y+ U2 g; @
  [
+ m2 X. d1 w% c0 ]+ W2 J    user-message (word "There are too many cars for the amount of "
6 @6 c7 w, x& e                       "road.  Either increase the amount of roads "
9 P& e1 f) x5 a5 q, J0 E& e. s                       "by increasing the GRID-SIZE-X or "
( I* [$ }! L% z  W$ y: M7 ~                       "GRID-SIZE-Y sliders, or decrease the "
! n+ I$ n* Q3 j6 }& L4 j5 D                       "number of cars by lowering the NUMBER slider.\n", G( j" `/ u; u% a) U( ]" t! G
                       "The setup has stopped.")% [% @9 v/ o, f' E0 j5 ~" {6 n
    stop- n$ q2 V, i" D" L- B: \4 q
  ]
$ j+ ~6 q) Q; i5 _
% M, G3 b5 L0 G  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& D3 N% p& |  `6 C  crt num-cars; Z# H' ^9 ?* Y* w7 J: B8 Z( L% e
  [. g6 e- X4 E7 ]5 T5 G( e
    setup-cars
  y. a' N. u! V! T% o    set-car-color8 k  M- i% M7 N, t
    record-data  L$ o& h9 i4 {* \' q0 ]
  ]
% k8 o4 u7 ^7 X2 l3 U1 [
4 P$ [% C# |! {- d7 k  ;; give the turtles an initial speed% i: r  C4 ]5 ~% V
  ask turtles [ set-car-speed ]/ D. q! M8 t2 A0 U" m8 J
( F% U; ]+ N6 ~7 H4 s+ v! r  ]0 M) q
  reset-ticks
+ M7 N& \* \9 H  Q" P1 P5 kend9 U/ r% I- E3 Y
6 I! f# s* d2 @: P
;; Initialize the global variables to appropriate values. x$ B4 W. U3 M1 i1 h
to setup-globals3 q. d; O- L8 D) \. E* {3 q& f4 c
  set current-light nobody ;; just for now, since there are no lights yet
8 }7 O. P$ Q. G0 w* W& W- f  set phase 0" ?; N" r( j( a9 Z: h
  set num-cars-stopped 0# A) w+ o5 e1 o+ e5 p
  set grid-x-inc world-width / grid-size-x
6 T& ~" k8 N5 n( @3 D  q  set grid-y-inc world-height / grid-size-y/ T: H1 D5 B" ~2 c# Q
+ g& z1 q: v/ S& \3 a
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 m0 D2 p& Z1 _! Q$ C4 P  set acceleration 0.099
% T) L! Z2 A. r6 ^end
8 n, y4 s  M( V  w& Y8 a9 G7 U$ }  v
+ d; g; A/ M2 p, N: ]  V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# ?# l2 {! ^6 ~1 R# y
;; and initialize the traffic lights to one setting4 \0 B4 L$ i) v; J6 z
to setup-patches
, j+ y6 U! t' P7 S7 Y+ k  ;; initialize the patch-owned variables and color the patches to a base-color
4 a4 L( O; S( d+ P5 M. {5 C* d  q  ask patches
& A- b4 T( |2 u3 K  [
* W0 G# U. p/ \" H% q    set intersection? false- _9 v7 v# C) ~
    set auto? false
* ]$ T0 M# X: }    set green-light-up? true
8 i; N  h( F, e    set my-row -1
. _: C0 G, \3 v* V" U    set my-column -1
  B( v! |' ^8 T5 ~& \    set my-phase -1
* [' {- q9 v  o3 U; F    set pcolor brown + 36 g! X% O3 U0 F9 b% ^5 o4 \* t7 P
  ]
# t' [  F' n: ~$ g  Y0 f$ M5 u/ Q- V+ |6 g/ e& L* r6 U
  ;; initialize the global variables that hold patch agentsets
7 J& N9 [6 o$ p! v2 C4 c3 j% U2 b7 Y  set roads patches with* f/ Z( R/ V9 R  K
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) G7 C  C! c# l) N$ X! ?
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 F  X3 l$ u4 j# ~4 }. d
  set intersections roads with, L1 D  w; {* G* b! K4 `8 o$ x# V
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 {. C9 L4 n* E1 {. w1 l
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' |6 Z% W, D# N# P6 K+ [3 O

% p" m  j6 u7 P/ g  ask roads [ set pcolor white ]- k0 A: X$ v* L4 A% q: r4 C3 {0 W
    setup-intersections
: H! N! C, s6 Mend
0 u$ y: T0 v2 }1 g% o, {其中定义道路的句子,如下所示,是什么意思啊?2 i# F3 P/ L9 {  b
set roads patches with
6 I  g2 T$ ]- A' t    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, e( ~. B, N4 H    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) p, E  t2 P6 j0 Y0 d$ s; U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, 2026-4-19 11:29 , Processed in 0.016945 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