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: 11932|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。- u8 a8 ]5 w" p% l) S4 H
netlogo自带的social science--traffic grid这一例子当中,/ d/ w1 j. x: H% j
globals
! C" R4 _' b2 |6 N4 X[
. k- J" G; r3 \# B# ^4 D7 ^  grid-x-inc               ;; the amount of patches in between two roads in the x direction
$ _: Y& |+ B' c3 N( P$ U$ _  grid-y-inc               ;; the amount of patches in between two roads in the y direction7 J5 O/ w8 ^1 [( m% {' h5 ^/ P* q+ R
  acceleration             ;; the constant that controls how much a car speeds up or slows down by if
+ q4 X7 a6 _; i/ r; O5 s                           ;; it is to accelerate or decelerate# S& U  S3 S1 J- k& F$ Q- ^1 ?
  phase                    ;; keeps track of the phase
7 S4 B- G1 e8 u3 E3 B& u/ X  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
/ {4 ~( k, ?5 g4 I: w, g  current-light            ;; the currently selected light
' O' K( B: ]& ?4 X5 s1 A- X
7 {+ y8 h, j# x) r0 }; a7 s. z  ;; patch agentsets+ X- D* F! ^8 ]' D! a. Q" s
  intersections ;; agentset containing the patches that are intersections, p7 k$ g- i* r8 m' v# A
  roads         ;; agentset containing the patches that are roads
8 K8 N, {5 T9 n" }. P6 g]
/ `4 e$ w$ J  a- I7 S/ I3 H. u
, a( p. o7 x$ y" y! ?' mturtles-own
& i( u$ V1 i" ^[0 _3 k' X; c) I
  speed     ;; the speed of the turtle
1 l- c5 a4 e- K* H+ c" x# s  up-car?   ;; true if the turtle moves downwards and false if it moves to the right, Q# A% f* W) s% g
  wait-time ;; the amount of time since the last time a turtle has moved5 e4 y3 r+ }- Q
]) [4 m; E1 d8 O8 c; p5 Q, V/ Z7 o
2 _( R7 }! U- y3 V6 {
patches-own- l0 {6 U5 z$ T% @& k
[/ a5 f3 Q  M* ~
  intersection?   ;; true if the patch is at the intersection of two roads* Q' _1 l; D4 e* f1 c0 Z' q, H) f2 e
  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.: E" y, z8 T, K% f% b, ]
                  ;; false for a non-intersection patches.
$ J2 q; S% e- B  my-row          ;; the row of the intersection counting from the upper left corner of the1 u. N% T  V& ~* P) g( J
                  ;; world.  -1 for non-intersection patches.
2 r" ^2 l  e0 J# B- R  my-column       ;; the column of the intersection counting from the upper left corner of the
0 {" t$ `! h8 o! W" \+ H                  ;; world.  -1 for non-intersection patches.
6 T% _7 L7 u" N% G  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
/ S3 f! ]4 }+ m! M  auto?           ;; whether or not this intersection will switch automatically., T4 ^; _4 _) b
                  ;; false for non-intersection patches.8 O2 C& N, O4 `" h: C, r# E* z' o
]. L8 e9 H0 J" S2 N
! a/ P( ~' Z" {# e- X

3 ~  O" @) g* @;;;;;;;;;;;;;;;;;;;;;;
2 [: F  w  i- {# g$ ?, `; j' q+ ?;; Setup Procedures ;;
, j/ J7 s6 E$ }; f" j( E;;;;;;;;;;;;;;;;;;;;;;
4 T* l$ C* n3 H/ P8 |; S6 o( ~4 }' {3 _+ U, j; {8 ^2 T
;; Initialize the display by giving the global and patch variables initial values.% }/ @# }9 _* o7 z7 E& I2 s0 z* I7 g
;; Create num-cars of turtles if there are enough road patches for one turtle to" O. ^, q# t3 \& e
;; be created per road patch. Set up the plots.
6 d. U9 E8 n, ^* N8 oto setup4 }% G% d2 R9 ?3 c; X2 }3 h% h
  ca
) @. }( m) H: P  n; o" B. x  setup-globals; f8 C& V- l% O$ `8 g

- C: y4 j) D/ i$ J7 L+ R  ;; First we ask the patches to draw themselves and set up a few variables
' p/ i; N' d2 a4 E" E  setup-patches
/ ]# H  o* u2 X4 A  T. _  make-current one-of intersections
: s- m7 T9 Z; p/ Z- J4 X  label-current  g  T( P* j) k1 ]) c

* [3 Y" n& v6 _" T  set-default-shape turtles "car"0 F: n: k# q8 J" {, }, k1 y) t3 E
: Z* ~- `# m- s) b( D, K
  if (num-cars > count roads)
9 m2 j* l1 E: i# {6 o7 k6 X  [
5 A9 s6 y. a; |% F! T    user-message (word "There are too many cars for the amount of "7 f" ?4 j& ]# x4 m# s) U
                       "road.  Either increase the amount of roads "
8 A8 w5 j7 J4 y. x0 Y& b$ |                       "by increasing the GRID-SIZE-X or "
; R$ q2 \9 @: X$ b4 r2 ~. }                       "GRID-SIZE-Y sliders, or decrease the "7 W- I; H7 m6 T; n& A' ~- x3 R
                       "number of cars by lowering the NUMBER slider.\n"
; R3 H" a& c( F7 H% Q                       "The setup has stopped.")
( h$ ^$ n3 F/ B    stop
/ _* i" j1 S! O6 Q3 x  M- d, R  ]
4 Y- v! E/ t. i  }# b1 V- n& }' B# ~9 X" h, A' ^
  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* }& h6 G' T6 K& s' F) L
  crt num-cars
: Q* U) w; u/ o% \( v+ ~! r  [
$ |- r, @% z; ~% ?    setup-cars
9 ^& p5 v; J+ x- n% Q    set-car-color
/ k0 f8 j# O( n& E    record-data
2 A& i# l7 ]" b1 @' K& a  ]+ R0 J8 O4 @6 [5 T0 q- h

* C! z8 `' W% I5 ^; p# `  ;; give the turtles an initial speed
9 H8 G% O" \! z; t- x  ask turtles [ set-car-speed ]
' q7 B. t$ l" L0 e7 t- u1 [' K7 w) v& ?
  reset-ticks
7 v, u" A2 a4 D0 e1 Zend
- A4 h) H6 x4 d: ^$ c! {4 ^$ k1 x( r: ]
;; Initialize the global variables to appropriate values8 q, ~9 w# |5 U' `+ n
to setup-globals
2 v+ O+ Q/ c+ U% d/ _  set current-light nobody ;; just for now, since there are no lights yet
7 f/ y3 X/ |& u# v  set phase 0
( i- e/ t  T. h  set num-cars-stopped 0& c3 g1 V  ]. U- w% s5 Q
  set grid-x-inc world-width / grid-size-x* e8 G% @- G8 h8 B/ L% O
  set grid-y-inc world-height / grid-size-y: W. R. s6 T# v/ G1 s; @

: K# p6 Y; z, ]0 ]* Y& H  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 K) J6 B9 R: H( G; F% t& @5 k
  set acceleration 0.099
; d, w$ l% o& s% P8 oend
" d# p* x4 f6 `: s6 \  I7 D. N: q" ~4 e
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 ^  t4 s6 M8 z% \& G7 J;; and initialize the traffic lights to one setting" \& m4 H! @, o2 P1 ?+ v  K
to setup-patches+ d; r! c0 Y$ g6 I0 \
  ;; initialize the patch-owned variables and color the patches to a base-color- J( u% ]$ t* i4 D9 h. g
  ask patches1 p7 X% w- R. r& _- y
  [7 z8 c0 x3 r& T; u
    set intersection? false
! I5 X4 E5 Z: O8 `( ?& ?    set auto? false2 @* \2 Z0 y2 S
    set green-light-up? true+ V) s4 _; l, n
    set my-row -1# o8 X4 w2 S$ N( R5 ?. {
    set my-column -1
1 K8 t5 l  L$ f8 O$ T    set my-phase -15 N+ }  C# k  K! t
    set pcolor brown + 3
& P. w8 }9 L+ U7 G  ]
9 ~7 |' `' N$ v$ t/ s+ g8 b0 O& m$ N& Y' r' f
  ;; initialize the global variables that hold patch agentsets
9 M& D; }; O1 g% u& K  set roads patches with
9 d6 X- _2 G  m* i( d- |    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& Y. n9 m  [; H4 t    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' z1 ], V/ Y) x
  set intersections roads with
; }$ [6 Q% z2 W1 Z1 m- |$ d    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
5 z: C: X0 z/ q" {1 h* ?( U+ ]+ h9 t    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# l/ m) B8 p* H8 [

! l* l" L. L7 u. C  ask roads [ set pcolor white ]
5 v' {+ C9 l8 L" f/ M8 x# h' X& T    setup-intersections# L" q; p1 y9 t+ \! n( W
end
- y4 I' X( _; |  p1 X; B$ ?其中定义道路的句子,如下所示,是什么意思啊?! {- S# u/ G3 v9 Q8 g
set roads patches with9 z. e4 Z  V0 ]# z2 O# \
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 q4 m/ t  b+ [6 \, X
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% \9 M* o5 G: o
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, 2026-8-25 01:35 , Processed in 0.017835 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