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: 11613|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。5 x$ I6 F# ?8 k$ D4 L9 @
netlogo自带的social science--traffic grid这一例子当中,' I, R6 E& a" K- }' g
globals
* X+ F* B. p, g* w[
; h* L) {; q5 m/ c( b" Q1 ~$ e  grid-x-inc               ;; the amount of patches in between two roads in the x direction
+ |/ v8 E( N- @) Y7 G7 Q" c- C  grid-y-inc               ;; the amount of patches in between two roads in the y direction- Z& u: J- U0 w$ y4 j% j. Q
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
. t# K. j6 W/ _3 ^) O4 `$ p                           ;; it is to accelerate or decelerate" N# F$ W9 U- @- e
  phase                    ;; keeps track of the phase
8 p0 `# e; D  o1 Z0 _& _* n, i  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure  O3 E  `! \! S9 q/ z9 S+ q
  current-light            ;; the currently selected light
% J* F& d0 Y0 U- Q, Y# M3 r4 Q) y) r: B5 J  G5 o' w& i; }
  ;; patch agentsets
/ u( W! C1 F9 d8 T- }: W) K" R  intersections ;; agentset containing the patches that are intersections
- F; U) ~, n  B* _8 K  roads         ;; agentset containing the patches that are roads
  P  d) m% B' ]' V]/ ]% Z5 ~, u$ F' v5 I0 M7 E' \! w
* V  [( [0 O) Y6 D- g: v( B
turtles-own/ l* I1 h* ?, Z: A# H
[
+ E/ B0 q# h0 X" H5 z$ l  speed     ;; the speed of the turtle
1 r& Q8 i6 v5 |, ?  up-car?   ;; true if the turtle moves downwards and false if it moves to the right. o# c" ~: v7 f! m3 @% h
  wait-time ;; the amount of time since the last time a turtle has moved
3 b) L+ E4 K  b- t]9 ?7 [7 C  p# p& E+ U% h
" ]9 G$ |" K! Z9 L2 b" [
patches-own9 p% k4 s' n+ ?7 ]
[
; q- o+ X$ D( g8 O% V  intersection?   ;; true if the patch is at the intersection of two roads
# |# K& @+ t. I6 H( n$ ~7 e  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.1 a) d# |% k8 l" k4 `8 i8 C
                  ;; false for a non-intersection patches.0 P# L: y3 d9 g+ C: j3 s
  my-row          ;; the row of the intersection counting from the upper left corner of the. k, Y- c9 k) U- {9 N' Q
                  ;; world.  -1 for non-intersection patches.
* p  U) U5 O% f" ?' Z  my-column       ;; the column of the intersection counting from the upper left corner of the$ z1 A  m! k. E5 a% T
                  ;; world.  -1 for non-intersection patches.
0 e+ b, w8 u$ O) n  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
+ f* b4 z8 L& ^! ~/ m  auto?           ;; whether or not this intersection will switch automatically.! n0 g+ W) u. i3 [  B- i$ ~
                  ;; false for non-intersection patches.* R  @$ D# g- |+ R& W/ t0 c
]
3 E0 ]4 k2 h& s# X8 C4 d% T
  X4 `' {! a5 M2 x. P+ w7 Z5 T0 O* H6 l( ?3 @, G6 u
;;;;;;;;;;;;;;;;;;;;;;9 @8 O- a3 P2 v7 [, w/ u: E; _
;; Setup Procedures ;;  G! k0 q2 c; S8 L2 B
;;;;;;;;;;;;;;;;;;;;;;$ {% Y% I5 P# f% Y
0 S9 G& B% `! L  D" F" a
;; Initialize the display by giving the global and patch variables initial values.
- i# d! b! U9 \3 y;; Create num-cars of turtles if there are enough road patches for one turtle to
: z/ Q/ G1 h$ r/ m4 p;; be created per road patch. Set up the plots.
" j- d* N' ^4 H" K4 j5 E5 lto setup
6 k# R& P4 T6 D4 S7 I  ca
# t' K& \9 E% G2 ~- o; _7 \+ j& a& a  setup-globals% O9 V$ [& Y& ~& {# L8 C5 ]

( o/ o9 T9 v/ I6 i* O0 K  ;; First we ask the patches to draw themselves and set up a few variables
0 J; l$ {# p+ j- P* q# d' R  setup-patches8 D( `9 v6 g" ?8 L$ D: j
  make-current one-of intersections
8 h# D$ a8 J# @' a. i/ Q2 g* t0 D  label-current
# U6 _& L6 _4 y% S( c2 g
. j( K$ P3 W3 y8 ^! m1 t  set-default-shape turtles "car"6 v2 O4 A3 O1 p  T1 A; ]7 A/ l

5 t# v* O; p' q$ g( u  if (num-cars > count roads)
7 l% X5 O( G0 H  a  [, v& \7 s8 p  E8 U: d+ D
    user-message (word "There are too many cars for the amount of "
+ c( A  @* r9 _- f4 X                       "road.  Either increase the amount of roads "
! d6 h+ F2 V+ ?$ X# O                       "by increasing the GRID-SIZE-X or "
( A; d+ M0 K4 i+ k8 `                       "GRID-SIZE-Y sliders, or decrease the "0 G) B2 d* o8 }- D
                       "number of cars by lowering the NUMBER slider.\n"
. I" e' _( x' s3 Z( U+ s                       "The setup has stopped.")5 y% Q' H+ j8 o' r7 V9 z% T
    stop0 r: J  V3 O6 y: i
  ]
, A# h3 h# v* @! o
4 K! K* ~. C$ u2 N  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ D9 m2 ?6 }( n% m+ ?: g
  crt num-cars
6 T4 Y7 ?3 G# [: z+ Z* Q  [1 c/ {/ `8 b$ Y/ X8 B! H
    setup-cars9 V* {5 N1 x' P
    set-car-color0 ]+ G* N- n" O8 {! U4 z* Q- a
    record-data- e: c$ J, x% m9 H2 a+ J
  ]
( n8 E+ i. E2 e' e; v  l9 p6 {
# C5 W* k2 U, @; k$ g  ;; give the turtles an initial speed, Q. K: }. W7 y2 P/ k% @: W
  ask turtles [ set-car-speed ]- |" F- w# v7 \% w* I7 w

% u( S) ]0 {" ]( @0 A3 p  reset-ticks
8 b# Q6 S1 L! f' b5 q' s- [end
3 c$ ]3 G' @) `0 d/ w
( W; R- W! U* j1 R9 r9 J5 Y4 f;; Initialize the global variables to appropriate values2 |& o. e6 y$ \1 c/ a# b
to setup-globals
: S0 D' d; y6 E! T1 C  set current-light nobody ;; just for now, since there are no lights yet2 {1 k, S$ M+ _# p+ V  _$ I
  set phase 0  V' r) T9 r9 h$ V% P5 o9 p
  set num-cars-stopped 0
$ T. a$ o1 J( B% n# x  set grid-x-inc world-width / grid-size-x8 D/ @2 t" |" u# R* I' m- [
  set grid-y-inc world-height / grid-size-y  w( C. s/ ~; l  W$ m
# L: Z4 U& O( [' I7 O
  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' [$ x$ x/ c2 I% h# V$ q  W6 |
  set acceleration 0.0994 y) ]8 f" n' Y! I
end
) J% O: V  D, z( L; l3 `4 k4 P5 m  P  g: {& z; B" V
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% N" j' D+ X+ U1 d! X, ?
;; and initialize the traffic lights to one setting" \" |+ z4 ^3 ^( \4 b0 t* K- j
to setup-patches4 u7 W& c# _- v' y
  ;; initialize the patch-owned variables and color the patches to a base-color- a: F& a5 k8 f% ~6 ~
  ask patches
* v( Q; Q  b; @$ W  [
6 V, v7 i3 E1 V, a    set intersection? false
2 b- d  A7 J3 O  Y# [1 L    set auto? false
, ?6 W, ?$ m3 M, X9 s    set green-light-up? true1 H1 u1 m: ~& i
    set my-row -1
! v/ w3 r0 p6 z. w+ D; \9 c" t1 g5 R    set my-column -1
0 [+ n3 b. p4 ]# z. q    set my-phase -1
  x* R+ k; H) `3 j  N- ]    set pcolor brown + 3
2 V( ?2 ~7 d% y. a! g$ T) z6 e  ]0 ^4 i9 v7 D: K
. c6 |. r' w: n: y/ S; W: o3 g# B
  ;; initialize the global variables that hold patch agentsets
! V* u1 V% i& ]# y  set roads patches with
/ B- w+ H+ L# t- w0 m0 h    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, r3 e1 v" k6 J6 ~; b' l    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 z; i; |# y2 ]8 E8 z' K  set intersections roads with8 E, q8 u6 p& N
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and  W4 ~' H8 t9 G3 k+ l- ~. E
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 p9 @0 e( E2 r$ T

3 E- Y6 `7 j5 z* v  ask roads [ set pcolor white ]" s& x" I! ]/ ^, }5 I4 d% C* T
    setup-intersections& U$ M8 g, U) R8 M
end
' F  a" ]7 j( x& [$ z其中定义道路的句子,如下所示,是什么意思啊?
/ s; @, }* W6 Q. \  X. k8 U5 H! x set roads patches with* u# D. M7 i" o# e# l+ W
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% c4 \: f. f! |
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; r4 g/ }* Y9 t: A6 c
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, 2026-8-6 18:29 , Processed in 0.016697 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