|
|
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。
* C; ?. g9 |7 {+ s. _; E+ ~; Anetlogo自带的social science--traffic grid这一例子当中,
& q$ J( b3 @( O& B# I) j8 _* c- tglobals
6 W" E# C5 o$ k6 c0 ^[ J4 B$ V. p. S9 E9 \% o
grid-x-inc ;; the amount of patches in between two roads in the x direction
; T9 i" |/ e+ ?) H$ ` grid-y-inc ;; the amount of patches in between two roads in the y direction
* H. {: N- _% o* {' R8 o$ g+ b: k acceleration ;; the constant that controls how much a car speeds up or slows down by if3 w- U: y$ E. f3 @) L- P. R
;; it is to accelerate or decelerate
2 k, }6 I" ~; ~) ?* @5 ^ phase ;; keeps track of the phase
, L. U" U" t3 Q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# w3 i$ J2 O; b! ~, r3 B current-light ;; the currently selected light
- z p* c' W$ A1 z) ]+ U$ g/ q" V% E3 x( N1 P& M# r9 W- |
;; patch agentsets+ r) E$ O x5 l
intersections ;; agentset containing the patches that are intersections
9 P* ]& Z4 ]% u) t& F$ J( X4 ] roads ;; agentset containing the patches that are roads
( C: P0 Z0 m4 q P y3 r]6 d. o# N. J1 _' A5 X3 H
7 }' s6 o J+ E0 ~
turtles-own5 d, C Z0 g5 `+ X i/ n9 z# v. T# j0 c
[
% I2 }! f6 m l. `1 R# c3 Q speed ;; the speed of the turtle4 g" f7 f5 `+ P) G+ E: }
up-car? ;; true if the turtle moves downwards and false if it moves to the right0 g. a5 v) Z! \9 P
wait-time ;; the amount of time since the last time a turtle has moved, V I6 ?! t/ U4 t/ B3 _
]
3 G. {+ {* v8 q' p, v1 h0 _! z9 ?# o) z% }6 V! ^8 e* E5 U
patches-own
) Z! c% r" S* g. p$ B* r4 U[7 q, H$ o# M9 I; r
intersection? ;; true if the patch is at the intersection of two roads: j0 f' s+ B% C
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' W- E+ K! E: r ;; false for a non-intersection patches.
! u+ Y7 |1 N4 S8 f, W. r& P my-row ;; the row of the intersection counting from the upper left corner of the) F% ]4 s5 M9 s( L/ U
;; world. -1 for non-intersection patches.
/ Q Z: _1 o# ^/ q5 x+ o% | my-column ;; the column of the intersection counting from the upper left corner of the9 h( `5 L$ o2 n% G2 c9 N
;; world. -1 for non-intersection patches.
5 ~8 u' {8 S+ {2 b l/ v my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% y. ^. w6 d# h. }4 @+ h/ O* V auto? ;; whether or not this intersection will switch automatically.
5 P7 H% D9 R% \' z& I ;; false for non-intersection patches.
" h# _" z7 r, x) ^8 g# V]
% m) {8 G$ w t: c5 z9 A6 S& @0 i! m2 n: F C1 s
+ P$ Z5 E: l k
;;;;;;;;;;;;;;;;;;;;;;
( D- q7 x: _' |) O;; Setup Procedures ;;9 J% T- U# f; _; R! I
;;;;;;;;;;;;;;;;;;;;;;+ A/ n E, l' @$ h& d
3 ~3 G) `' B# h& L3 v! s9 |, N
;; Initialize the display by giving the global and patch variables initial values.7 h# Z5 v* R# h& [. }; W8 T+ p
;; Create num-cars of turtles if there are enough road patches for one turtle to
& c' p5 {& m% \;; be created per road patch. Set up the plots. Y& H0 i, L1 \6 X8 b# f
to setup
4 U. ^8 P3 Q& t% x" r6 W ca
: o6 s2 S3 C; B setup-globals
3 B/ ~) V$ c: m9 c& k
' u- Y+ ^9 V& z0 H% s! n) H ;; First we ask the patches to draw themselves and set up a few variables# c, R2 N8 z! P8 M& F
setup-patches. T7 w& {* K! }4 G5 [4 ^
make-current one-of intersections' z2 L. _* M2 `/ h: @% h
label-current! ]* Q5 p2 G" q/ m
0 K5 S: g2 o( z4 f- q
set-default-shape turtles "car"/ Y; R5 _# Y0 S! a
1 }/ p7 z, B( d
if (num-cars > count roads)5 q' _3 F4 i% N' ^; A9 E- k& j& Q7 x9 P
[
7 t6 W, t; I' x3 l$ c9 R2 Y1 Y- U user-message (word "There are too many cars for the amount of "
$ X! H, h7 U& C/ V7 t* ?6 m "road. Either increase the amount of roads "; G; m, @& v) ]
"by increasing the GRID-SIZE-X or "; J% l: e i6 ~' U! m$ B E3 C1 o
"GRID-SIZE-Y sliders, or decrease the "
( W& G) i: Z' z! b4 D "number of cars by lowering the NUMBER slider.\n"" }* d7 a% e d5 S: J
"The setup has stopped.")
- b, W9 z6 r/ }. n. Q stop2 v B. P9 q% k4 u2 |+ _# r/ u. ?
]0 M: b. t6 U2 y
* A8 T# G R" B" x ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ h2 ?' X3 O c" c crt num-cars
9 M9 R/ r* s/ f: _4 Y( m [
8 B0 P) h( {) A: v+ t setup-cars3 r6 `$ z7 C7 _7 C' n
set-car-color! o' J" f' f3 M) K4 N
record-data5 u! Y5 ]/ I3 S; S+ y @+ ^" |
]
& }' x5 S, r k8 z9 ]
; x* r$ d" s" w' Y* ~ p E. v' ^ ;; give the turtles an initial speed
2 P+ P, `+ ~& e* l2 ? I ask turtles [ set-car-speed ]% f, d4 Y) F1 y7 z' R- U
9 C* S( x2 c$ ~+ S
reset-ticks* B# A8 s: n$ b- i
end
5 k) U* T$ ~/ v( h5 l2 f4 b% u2 @! O# D) u7 b$ [; q$ m; M
;; Initialize the global variables to appropriate values5 r. k& o4 g9 A& q/ \+ o
to setup-globals
7 f! p1 f3 B8 G; y, K* b set current-light nobody ;; just for now, since there are no lights yet
; m8 Q. e7 [' u! I, V, q+ C0 y! n F set phase 0
, S% l7 v- y R9 x. g set num-cars-stopped 0% N: g9 ]: r# O8 }- F% O9 f6 e
set grid-x-inc world-width / grid-size-x! G. ^6 V: U% p6 H4 s) p
set grid-y-inc world-height / grid-size-y
3 O" u/ ^# P- m$ l' k1 n1 V1 p4 w( t5 g4 b* X2 [
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 z4 r" A* C2 G5 [! E {
set acceleration 0.099( G3 i3 o5 F A1 h$ Q( U5 l
end+ _1 M& W% p2 J' T* J
, v! Z( C$ K4 c;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
- o7 d2 a: p6 w4 p: p;; and initialize the traffic lights to one setting
% ?* j6 y4 c4 O& a# g0 u2 d0 i0 vto setup-patches, F/ `4 X* O2 B1 o* N- B1 N
;; initialize the patch-owned variables and color the patches to a base-color
+ U. E/ |2 j& A ask patches, m( P. D+ A6 R% x9 S1 U
[! p6 i! Q1 A e( x/ f( K/ f+ b
set intersection? false
* Q3 e+ G, `( X9 e2 W) E( _% A7 C set auto? false- f0 B# N( o% i# B
set green-light-up? true
/ b& j; G( Q8 O" ?8 P1 h5 R set my-row -16 H6 `1 ?$ _, O5 N- b, x
set my-column -1
% }+ o* b* |' M! x; N- O! A) r* u set my-phase -16 G) o1 X" a% y# i' q- J. O
set pcolor brown + 3
{6 l; \* z( T* z: i: j ]3 D9 K1 I1 X: m5 C e0 U" q' Z
5 C* o" P) E" h1 l6 I: t ;; initialize the global variables that hold patch agentsets
0 \/ _5 F$ L, Z; V" w1 ~ set roads patches with/ Q/ e% [* u; Z+ v) h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, S1 u# _6 O( s4 \& p" z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 M9 T8 I, _/ `9 N set intersections roads with
; I' p& J4 s# Y7 i3 }) q; h0 X) ~, N8 C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 ]4 d% x' P+ W( d/ {$ E: g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 m$ d, x4 n( p/ y) }# r
f! M4 G2 e( j- R$ b2 p ask roads [ set pcolor white ]0 O3 Q' S# d; ^( _' v) o/ f' h
setup-intersections
3 A" j1 U4 V$ ?+ ^) J7 s3 nend
# D7 b5 C/ O5 B' i3 w% H& U; x其中定义道路的句子,如下所示,是什么意思啊?
. @; P2 l' J8 x% p8 Z set roads patches with
) X+ E4 y5 b c3 S2 E9 I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 q$ h" k/ O2 y3 @5 N; c) y5 S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 b; s3 c+ ], c" i& T* ]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? |
|