|
|
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。% q% a- z5 z: L
netlogo自带的social science--traffic grid这一例子当中,7 l3 i6 m- M- p8 K. s, d
globals! a) _- X+ p7 g! X% S
[
8 \( m% f1 n+ x7 j* U0 b grid-x-inc ;; the amount of patches in between two roads in the x direction! n: { ^; i/ ~5 y# q+ c( r$ Y
grid-y-inc ;; the amount of patches in between two roads in the y direction
. `# D( d* u5 O( N% U7 N3 T acceleration ;; the constant that controls how much a car speeds up or slows down by if
! n- O: T0 l1 W& j; B ;; it is to accelerate or decelerate1 a7 O- z! u |
phase ;; keeps track of the phase. n3 c E& v, c& z' O7 J( w. R9 X
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
6 {# f1 H3 O3 i3 e: k0 m! u current-light ;; the currently selected light2 H- H7 k, f" N4 X* i' h5 f
/ W! `! L* [% ?5 F9 ]+ ~; D/ r ;; patch agentsets: O! ^2 u, L2 J& [! ^
intersections ;; agentset containing the patches that are intersections$ c7 K3 G6 w; ]' O m
roads ;; agentset containing the patches that are roads4 J& D7 ?4 q; g' s6 h
]+ D- s; I0 E. z' F1 |
3 }& I' C5 x! p8 R. a2 |; |
turtles-own" H6 f: w; q7 \0 C B6 A+ B. C
[% x i9 _" ^: p: r3 s& N
speed ;; the speed of the turtle/ G$ Q6 n! i7 {& W% a# c! [5 t
up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 `4 v2 l; f: Y# |! E wait-time ;; the amount of time since the last time a turtle has moved4 d9 |+ R" Y& [; O" \
]
) v: C, H( S# b0 i6 d# D
9 b! k+ c5 t. g/ B( Fpatches-own/ A* ?& @8 d8 [/ @
[
0 u5 m0 ^5 h9 l8 e1 h) D: Y# w intersection? ;; true if the patch is at the intersection of two roads4 c; g( ?5 H; M* \1 t) z, T) Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! A+ A8 E" [; n: G: @: N3 I ;; false for a non-intersection patches.
3 {7 k3 |& {1 j9 A7 L# Y' V( K my-row ;; the row of the intersection counting from the upper left corner of the
7 i8 R! O6 J4 q8 j ;; world. -1 for non-intersection patches.4 }6 b3 b7 E, ]. b7 O0 X
my-column ;; the column of the intersection counting from the upper left corner of the
. m+ }7 |7 J% s: M ;; world. -1 for non-intersection patches.
5 Z( h1 A+ Y! P9 H! v+ A my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 U7 F$ S/ f- D: n. l5 B6 I auto? ;; whether or not this intersection will switch automatically.) P( g8 W& h5 y& B3 U
;; false for non-intersection patches.$ Y6 _% \* }$ |* U! x7 J2 P
]3 a6 ?: h0 d+ u
, I+ H# _! D0 n
6 T6 W# N; k" M# k) c7 H2 p;;;;;;;;;;;;;;;;;;;;;;
+ s9 x D$ o$ ~* A7 R, \;; Setup Procedures ;;/ @3 k* N4 o) r1 G: {3 V
;;;;;;;;;;;;;;;;;;;;;;
: }2 r2 q. g% \& _( @0 Z
7 n4 l9 D( u& ]# N6 y;; Initialize the display by giving the global and patch variables initial values.4 x$ |, C2 g1 u# {% @
;; Create num-cars of turtles if there are enough road patches for one turtle to; P0 I- `/ H- E- d# _
;; be created per road patch. Set up the plots. T/ V6 S2 A3 a4 ^
to setup4 E( S: b2 \. _4 F. m
ca
# \5 j) c1 u6 Z2 `5 @ setup-globals
% E: S8 E- c" K4 y$ r
( H: }2 B Q" f+ T9 [" g ;; First we ask the patches to draw themselves and set up a few variables: F4 ?- r) ^: _3 I
setup-patches& J: L8 M6 n" z4 e6 \$ [
make-current one-of intersections
* A4 p- W+ U4 v# o& J2 l label-current2 H# ], j- K* c7 H+ z
- F( {: c) a- C9 ~1 j( f" `5 s: e set-default-shape turtles "car"
: Q2 ^, ~" B0 N8 ]: |' c+ p& r; \4 f. J
if (num-cars > count roads)
/ J- `2 a" k- X+ I$ p/ `; t8 Y [
~( V+ ~( `" f% w user-message (word "There are too many cars for the amount of " ~' I% @8 z3 c! c9 @$ M0 p' H
"road. Either increase the amount of roads "; s$ k6 z/ N- E/ h
"by increasing the GRID-SIZE-X or "
/ z1 T3 r1 a! E" V- C0 Z "GRID-SIZE-Y sliders, or decrease the "2 e0 b% _( g. I8 O0 P+ G
"number of cars by lowering the NUMBER slider.\n"
2 H7 _" j# f8 i1 a* U, ^+ { "The setup has stopped.")0 g1 z$ C; R" a) c+ k- o
stop
8 s4 w9 k9 [- y e& _ ]0 m1 X# X& [' w
" d I! n Y& Z! \+ r5 ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ _/ P0 x9 i7 J" [9 t7 Q
crt num-cars
" x6 C' U2 H, J* x G [
4 X0 l7 q) P' p2 J setup-cars; d; H) o5 Z* ?3 l, N/ ^: l
set-car-color
5 o- ?; F3 G' J+ L0 s" T7 k record-data
l, R6 W3 \9 x. Q ]
' A, G* `. }6 T' t8 W0 E5 }" H
- m! Q# p) a9 o( }3 d ;; give the turtles an initial speed
# d+ Q' S( Q' C- w ask turtles [ set-car-speed ]- R, I. } ~# x5 m3 N. v/ G6 w
9 x9 d" A! [: U' }
reset-ticks
, p# {& k" ], x# R( Fend
( K- _- a# Y' o1 M6 h
3 k, M; [/ \3 g) {* Z( l;; Initialize the global variables to appropriate values* b- S3 e4 C6 W- v& \
to setup-globals* X; {, ^3 L9 Z# U4 P* c
set current-light nobody ;; just for now, since there are no lights yet, H9 M+ g# V8 B2 R( W
set phase 0
$ u- f4 m/ L; |) k1 a, ?* ] set num-cars-stopped 0
2 C/ q/ g; w% K set grid-x-inc world-width / grid-size-x
' ?- E' Q# y1 A' Y4 j" h; _/ L: Y set grid-y-inc world-height / grid-size-y
2 T: K6 E9 U4 T7 G
$ t% W, \- x1 a8 P; f$ t' ` ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 z; O8 a* ~' ]
set acceleration 0.099. ^' _& }$ H* k' P
end6 _ _8 P+ G: M: w3 t
! p( K5 ]7 {1 {* @9 u, p, V* H
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, t6 h( y1 a- g;; and initialize the traffic lights to one setting
' E; D2 E! B! v2 O: ~& A9 {3 H: Yto setup-patches2 I% h) w2 i5 ]
;; initialize the patch-owned variables and color the patches to a base-color$ L" }, p1 F, ^, d( W* ]
ask patches5 y! f0 v7 s, M4 o
[+ b: C, R9 A$ ?
set intersection? false G% V9 Y$ n S$ ~/ ^2 V
set auto? false% p1 l0 v. c/ C: p K Y
set green-light-up? true
; r) Q! @; R2 M$ l set my-row -16 |; y( w3 [2 e: ]4 c c2 s0 d
set my-column -1- W& W+ h7 B( }/ g
set my-phase -15 |6 X) l# `" _/ w2 s! @
set pcolor brown + 3
! b* ]6 Z l$ G: Z B* t ]
) j0 i7 }) s. z" _1 P6 m* S& a- C6 x
+ d1 s: U3 s5 b ;; initialize the global variables that hold patch agentsets
! P! D+ P9 _: y& m2 V$ i set roads patches with
- p5 j/ o) U4 w0 {6 _9 {4 M0 C+ m, U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 Q; J+ C4 a6 g; j9 T: [! i9 e5 I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) m$ B- i( K) Q2 B set intersections roads with. P* _- _# w" E" C- Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ B. r! X* x1 p9 ^% o6 j# O v5 { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! f9 R/ x# w( R5 @
: |( v# J4 u/ M6 J I
ask roads [ set pcolor white ]
$ y1 W1 l, T- |! z$ { setup-intersections
! D( r- w! @! K' uend5 S! E9 b3 E4 p$ A' M. |3 U
其中定义道路的句子,如下所示,是什么意思啊?
2 e+ `+ @1 i4 ^1 ] set roads patches with
6 a. S# u5 ?9 u1 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 Y/ W' l, X& }9 E9 a( m+ k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 E3 t# m |- N, f& U% x- z! ^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? |
|