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: 10545|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。: m6 `9 E3 L+ \; |; @7 p8 D4 f
netlogo自带的social science--traffic grid这一例子当中,
) G. c/ [' T% W9 F, {globals
5 C6 O" }0 }3 B* D* c, F7 y- Z/ C8 \[
1 m- |2 k7 s' g  grid-x-inc               ;; the amount of patches in between two roads in the x direction
0 g: ~2 r- G. R4 @2 [. V  M  grid-y-inc               ;; the amount of patches in between two roads in the y direction
: a) ~0 P( i8 P1 {' F  acceleration             ;; the constant that controls how much a car speeds up or slows down by if4 [( i; V% Y; {8 d3 j! Q
                           ;; it is to accelerate or decelerate
' N2 v3 e1 V  p* h- L6 y) h% t. X: `  phase                    ;; keeps track of the phase- {0 ?! T+ f/ m9 V/ h
  num-cars-stopped         ;; the number of cars that are stopped during a single pass thru the go procedure
% Y: s' B; G, \# X: ~; a4 T  current-light            ;; the currently selected light
" [6 b) k( ?3 u2 o
3 s# W8 M1 O5 K! H/ i& i, S  ;; patch agentsets
" W5 w4 x$ N3 q+ @) e5 w  intersections ;; agentset containing the patches that are intersections
: u/ P% L4 G, \; E3 n* }; X  roads         ;; agentset containing the patches that are roads" n/ E5 X: p% q
]6 S9 i1 Y; i( D/ O

) Y! Y7 b0 K) W* Eturtles-own
* _. B6 p9 z; z7 p: h2 @' ~[
) g; q: e# x6 R/ u( c  speed     ;; the speed of the turtle* N+ p( f  m) X- F
  up-car?   ;; true if the turtle moves downwards and false if it moves to the right
' ]8 @7 x+ J6 K5 a( Y; Q  wait-time ;; the amount of time since the last time a turtle has moved
0 l7 d- q; r" c7 B+ o]
: l+ X2 K! z. U" ~9 E! n
! t: w7 j# a' ?  G, Dpatches-own
# q* O6 A& G4 c6 j9 v[' U3 P; k" j- s+ \! ~+ g/ q/ F# z
  intersection?   ;; true if the patch is at the intersection of two roads
& c& j" i& r3 e7 w, B& O1 ?  green-light-up? ;; true if the green light is above the intersection.  otherwise, false.
4 Z1 Q: G* G! M9 l: f6 w                  ;; false for a non-intersection patches.
* c! y- }+ [$ {! z2 G. l  my-row          ;; the row of the intersection counting from the upper left corner of the
7 h, F; C# z( F7 R) X5 |                  ;; world.  -1 for non-intersection patches.) q9 C/ O$ v* ^! M: U2 p
  my-column       ;; the column of the intersection counting from the upper left corner of the
8 x! n; f# u; \; m; t                  ;; world.  -1 for non-intersection patches.5 y/ A% e; d  O2 M. A7 U
  my-phase        ;; the phase for the intersection.  -1 for non-intersection patches.
. [% N. h  j' T" Q  auto?           ;; whether or not this intersection will switch automatically.3 L+ a) H$ K! k8 P4 E- \- w
                  ;; false for non-intersection patches.
/ @) t, K' V; |$ C]
; [+ @3 Q/ m) n4 A6 n! s2 ^) S' K1 K  g, H: `1 a6 ^2 N' ^5 _

. g0 d& N9 f- A;;;;;;;;;;;;;;;;;;;;;;
7 R7 k4 |# B8 [9 l/ c, G;; Setup Procedures ;;" F' b( \; _& `# p8 V  w  M8 |
;;;;;;;;;;;;;;;;;;;;;;
1 t" ^1 j- j& v& P  j
4 c3 F5 g: ~7 d2 A1 [& N0 k2 n;; Initialize the display by giving the global and patch variables initial values.
: u( s3 e: q6 j1 y9 g* e;; Create num-cars of turtles if there are enough road patches for one turtle to7 g, Q, O) L5 n9 A' g- d2 Q
;; be created per road patch. Set up the plots.* V7 R3 S( L3 y/ F6 u2 p0 J
to setup
. U) k' a1 x7 ]8 p0 _! @( W0 w  ca
3 @0 N4 \7 B1 b; M5 `; ~6 [' U  setup-globals7 J* i# N+ P3 W' Q. z9 N
6 Z+ _. O) ]3 r& d( b
  ;; First we ask the patches to draw themselves and set up a few variables' [- N" q- c4 H
  setup-patches% ?2 @- a: [1 m) M" o: T3 J
  make-current one-of intersections
9 R& T' A+ U% E$ q$ W  label-current
: z* e! s1 [, z# c1 O! i$ q; u
6 M( A2 q5 b6 D4 d' E- w. l6 V/ V  set-default-shape turtles "car"
2 W; I* u, u. D+ X/ V  F3 E- r+ y( s2 J) f$ H6 C9 x6 p3 S: v7 i
  if (num-cars > count roads)& a, X  G% t1 M& ~- F1 F& T$ X
  [
  b) a, P) W/ A! z1 K    user-message (word "There are too many cars for the amount of "
2 ~8 m' J8 Y9 ~* n9 w# f& V, M                       "road.  Either increase the amount of roads "
* E7 |! h- T4 M2 e# J! q! S                       "by increasing the GRID-SIZE-X or ". o  p- k: _- m/ v  ?0 S" u
                       "GRID-SIZE-Y sliders, or decrease the "5 @& q' Z  u" }. D7 j) t; d& G, W5 O
                       "number of cars by lowering the NUMBER slider.\n"( i* r$ \0 B/ i& w  L
                       "The setup has stopped.")& G$ r1 M) B3 l, r
    stop/ x# |: Q9 A3 i) R
  ]
+ |: U  r4 ]: }+ S7 V/ [1 B( R5 L
0 l+ }; l* \& X" p' u( H9 k( Z  ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 ?& F/ l; J) H1 {( ~8 n4 |  a
  crt num-cars
) O; d) f; N4 u' C  [  a1 y  b* U/ J9 h/ ~
    setup-cars
7 U! t4 G$ o% x    set-car-color
# l! E+ ~' w+ a# \4 o, K7 S3 m    record-data6 P- I" }4 i" L0 N, _
  ]" A! d% X; n5 B% ~
( y+ I1 b2 @/ @6 C% t! D& [
  ;; give the turtles an initial speed
, R- A0 o$ e) d8 c6 o* W/ H  ask turtles [ set-car-speed ]' w) @0 V6 j& i7 M% a

+ X# o( |4 T) ~& {# y- j  reset-ticks
# \7 y9 H$ w2 r- Q, E( kend
! g* S- w% s# n. K
( G4 f8 \0 r, h0 q- m0 _;; Initialize the global variables to appropriate values
) ?, I8 B3 t5 i  V! y& ~+ z! f# Cto setup-globals
8 E; Y. p" \" S. P* D7 K2 D  set current-light nobody ;; just for now, since there are no lights yet4 i& p; k- z8 Z1 X
  set phase 0
" ?) O% t& w  f5 O6 c  set num-cars-stopped 0# h) W! H/ x6 M1 \
  set grid-x-inc world-width / grid-size-x7 `. J+ [  F! w# W
  set grid-y-inc world-height / grid-size-y
; M% N/ T2 n; q; R9 C
' {2 k4 a( B8 P% y5 l' t  ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 F+ d' A7 \$ \5 {2 y! Z. v0 ~
  set acceleration 0.099- K4 H& N' H9 \# w6 K
end
  H7 M% F, C. X  a' M$ D) N- [) L7 C) i
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# S/ \. Q$ C+ G0 Z  B
;; and initialize the traffic lights to one setting9 _9 q: u: N) j  l1 l6 l; Y
to setup-patches
/ O2 x4 u# r0 N* P  s8 M7 b9 X3 w  ;; initialize the patch-owned variables and color the patches to a base-color' [8 Y" J* L7 r) e1 G2 z
  ask patches
1 c) f" s9 i* ~; O  [
! j0 o! H. v( T" b! h" H2 H    set intersection? false
& w8 ]8 _% k+ O$ U5 i6 b" ^. e    set auto? false
4 K9 j% [2 e6 S    set green-light-up? true
4 B1 q) t$ i1 Y) {) J0 R5 Y# w    set my-row -1
* ]; z" |) L4 f$ E. q0 i- Q' {    set my-column -1* T9 {& P. g* x! _1 Q6 M
    set my-phase -1
- L+ I, M% T. H2 o* Q- J9 c$ u9 l    set pcolor brown + 3
7 I0 f' ^1 ?8 y. K8 v. Y  F  ]$ `. t+ T$ n4 w9 A3 L/ g- e
8 I# Y7 B7 C9 B3 f1 T6 O
  ;; initialize the global variables that hold patch agentsets! c; b+ |) |( s* G4 y, ?$ A6 R
  set roads patches with
8 v; [1 x  u9 Z: g9 x7 D$ l    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% Q8 @4 e7 m" A( P, Q    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 _2 @8 ]3 l/ L3 a9 _3 A7 |
  set intersections roads with, U" e: R7 c) A7 f& C4 U6 w
    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 n- \4 Y9 _7 u5 t" ]- g
    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" _6 T9 U8 e1 {' l' U6 F2 c) G8 k8 U* I% W2 ~) _; b7 A- V0 h
  ask roads [ set pcolor white ]
. n* ~3 ^% M& u2 K) {# t) t  s, z    setup-intersections* Z5 g4 \1 R/ D. d8 k$ v! w
end/ @/ X# f" ]- v" a; b" @
其中定义道路的句子,如下所示,是什么意思啊?
5 S( x% U/ W( `6 S* s* | set roads patches with
" W$ e. j; F6 g" O    [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 v: _  M8 q' K9 G3 f% ]    (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 e* c) E; G1 l0 y0 _2 J9 B, 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, 2026-6-12 22:33 , Processed in 0.015080 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