|
|
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% K# |9 k8 u. m/ C
netlogo自带的social science--traffic grid这一例子当中,
. A }8 Z. s8 B. X& Yglobals8 K5 s+ X5 l1 g* u1 X
[
$ s( {" k9 E; R z% V grid-x-inc ;; the amount of patches in between two roads in the x direction
+ B# v, N2 ?) Y grid-y-inc ;; the amount of patches in between two roads in the y direction
1 N# ~4 d. D; y2 j: ~6 w' ] acceleration ;; the constant that controls how much a car speeds up or slows down by if6 K C* D/ z0 K9 ]* I! f/ M
;; it is to accelerate or decelerate
6 ?) W3 i$ t1 s* x* n! | phase ;; keeps track of the phase
9 _6 w; b7 i8 M/ ~% Y* } num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 O4 K0 J, Y$ B- F: _' n current-light ;; the currently selected light
* P, n: g" o0 T5 ~
3 X: y/ J+ w! L$ b: w0 n ;; patch agentsets
7 M! w3 |' M8 I* A* [7 e6 U intersections ;; agentset containing the patches that are intersections& \1 p3 S7 x7 v/ ~1 `. [$ r
roads ;; agentset containing the patches that are roads, C. h( n2 g3 C
]/ j ?5 A7 H8 C# x- K+ u+ ~6 V
" z6 w) b1 W2 m
turtles-own/ F& p4 G/ |8 M& }4 \' w8 b
[
! x5 O- q# }3 @7 i! z: b, G speed ;; the speed of the turtle, S) T: @7 g0 n) t) c( ~8 S
up-car? ;; true if the turtle moves downwards and false if it moves to the right- w6 e% y" Q' Z2 Q) H) A
wait-time ;; the amount of time since the last time a turtle has moved
y" r8 p1 J7 {+ I]
% I7 ~. d# J, U! Y& D' _6 Y6 }' z" Q; a2 G# f( r' w
patches-own. u: Y+ K$ U1 P7 l4 p, N7 R
[$ r! z/ D( M+ A# @5 ~! n
intersection? ;; true if the patch is at the intersection of two roads
: }' Z' r% q; \0 |7 z, B) \ green-light-up? ;; true if the green light is above the intersection. otherwise, false.; e8 d! S3 a8 f$ J2 X% _
;; false for a non-intersection patches.
+ D' H9 H* C: T$ N- \3 j( y my-row ;; the row of the intersection counting from the upper left corner of the( d+ @* |8 K. {, S( a1 s0 |
;; world. -1 for non-intersection patches.
. ~/ Q+ g+ `9 Z# I" ]" y+ R( U! T my-column ;; the column of the intersection counting from the upper left corner of the
4 c i4 N( o, t7 ~( S2 ]2 h ;; world. -1 for non-intersection patches.
/ B6 z' `) @0 A my-phase ;; the phase for the intersection. -1 for non-intersection patches.- t- w$ N! A, R9 _, G7 c( D
auto? ;; whether or not this intersection will switch automatically.) D! Q6 d% _1 h1 n! }+ ?0 y# a5 D% B
;; false for non-intersection patches.- k' F& J+ q0 p' `
]
) {. s4 O: ^: o' B' O% E/ N: @/ u$ R2 m4 ~9 W$ S7 c
6 X. H% p: \( A- l
;;;;;;;;;;;;;;;;;;;;;;: L& ]5 o% c# ~9 h3 ?5 R
;; Setup Procedures ;;
% J/ V6 \: ^: r2 u;;;;;;;;;;;;;;;;;;;;;;
2 |1 |! A( U8 T2 U$ l" X+ ~
- @6 B6 V. u3 f1 L& I# G+ M3 u;; Initialize the display by giving the global and patch variables initial values.
7 I0 L. x2 k, j7 j;; Create num-cars of turtles if there are enough road patches for one turtle to
+ [: }( ?* }) Q f;; be created per road patch. Set up the plots.( e0 [) c7 h0 v6 P( L+ D
to setup, L$ L( ?9 G: r/ H: X- f( v# Q
ca$ i- x3 H- N- g; z
setup-globals
+ M, ?) r" e; D& }0 u7 _) {/ Y
2 {8 Z9 ]- U! T9 Z ;; First we ask the patches to draw themselves and set up a few variables
7 I4 a8 g) I5 f, T R7 F6 Z setup-patches
. O8 { s' t( L9 n. w; h$ o make-current one-of intersections. Z* m0 k7 [( r% p2 y
label-current$ Z3 `7 L- n- K8 s8 M l0 l3 i. a
& w! a1 e- R7 Y3 y" k) X8 ` set-default-shape turtles "car"
, b+ G8 G+ ~$ ?% r6 G3 [" B3 B6 c: J
if (num-cars > count roads)$ f# o& E" A- S y. `9 Z7 b
[6 e* e0 _: ] Z
user-message (word "There are too many cars for the amount of "# O3 `1 A3 R2 [! P6 t7 _
"road. Either increase the amount of roads "1 \8 D; K# ?8 o+ m; m- \
"by increasing the GRID-SIZE-X or "
: r7 m6 i5 g$ E. d2 G2 M "GRID-SIZE-Y sliders, or decrease the "& m7 C+ t/ T/ \3 Z; ~
"number of cars by lowering the NUMBER slider.\n"
' f3 q4 M% _0 _ ? "The setup has stopped.")8 R7 g2 R1 c' Y- Y9 E C
stop
' L" G F% g+ Y% J ]/ y. I+ i! f! s5 `( K
9 [+ \+ j0 n% d+ I5 V ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! z! @0 t2 J! {; N
crt num-cars
- U! P: C! ~) B/ A4 f: Q [" i" l, e* Y! w& n8 R
setup-cars0 \9 t$ T. o# M! G* d4 d
set-car-color
( T2 K W$ c" `* w5 Y: A% k8 Y record-data
# a' a& `% N: D* M j% o# G ]4 E$ j/ X- {0 N0 ]8 B
9 q1 G9 m: t- R ;; give the turtles an initial speed
* R: A1 I/ j3 A6 u3 K' ^3 | ask turtles [ set-car-speed ]
2 g/ y1 o& M4 X, D3 N/ ]9 t' K
1 x9 j& n a" k* @9 B reset-ticks+ m5 ]! l2 r9 Z: t
end
, }0 `8 x( J' x* e9 D& w8 A! Z8 P- ?( U { Z/ t" ?/ N. u
;; Initialize the global variables to appropriate values2 m6 t0 f1 [) X& h1 f
to setup-globals
0 L+ j5 R A) L* {/ q; q# }6 O4 }3 z5 n set current-light nobody ;; just for now, since there are no lights yet
* T) z# a: ^; ~6 f" g N: C6 B set phase 0
l, } f9 O: c* }, M0 i set num-cars-stopped 0
3 t: @2 c4 G3 c& p5 ^; s* @9 s set grid-x-inc world-width / grid-size-x5 n% p8 ]9 o3 {# a3 `. D% k: X
set grid-y-inc world-height / grid-size-y2 S% ^1 a) x$ N6 [# w6 H# B- p2 X
, A5 k P' O5 n ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% G3 c! e! Z' i* X8 N/ U set acceleration 0.099
% u9 A7 ^5 R) t# Lend
9 k1 L/ w X5 l0 G! Q
r+ v; M& B! g- p* e3 b( r;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 ^0 \& E' q) p
;; and initialize the traffic lights to one setting( g$ x3 I5 p P4 g
to setup-patches
- i+ `, h: {1 @ ;; initialize the patch-owned variables and color the patches to a base-color+ W; N6 b$ D! @- {) Z
ask patches
7 K% s! U& V' N. B: G [
' b9 w- \& o) c5 `5 @ set intersection? false8 {* b ~) E9 K+ o2 x7 y! G
set auto? false
# n$ D9 L7 K/ {; p set green-light-up? true
0 O2 [& b/ Y2 J( R5 A set my-row -1. I/ x+ A) e0 X( P, u
set my-column -1
" y4 N& @8 Z4 O6 f# @2 } set my-phase -1& x9 ^, ]* h' a
set pcolor brown + 3( b- `( g3 k* \, H
]
6 F$ |6 A- r: N: z8 l" o2 C
# V* C6 F5 B- j ;; initialize the global variables that hold patch agentsets, v% x) B4 k6 Q5 O
set roads patches with9 r; O) u( Y9 Y( |2 W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 q: V& k! C; ~ D7 ?2 v: K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; n( X3 b* A( J) _: M& [ set intersections roads with
. l$ M% t9 m/ z; E# y: e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 o6 ~% l& m% f. A0 L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ E1 K1 a1 O1 J0 m
5 e) b4 y0 r6 g( t4 i5 T ask roads [ set pcolor white ]/ _ q3 l/ I' w5 q7 N! o
setup-intersections
" X; X* a3 M2 o- K. F9 I8 k' }end. `& d: e: U( y2 f9 t# Y# \ \
其中定义道路的句子,如下所示,是什么意思啊?
) X. i) k+ T9 N7 o set roads patches with
" B- |+ \. ], [' m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 K& w) H$ D. s% a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 ^7 ~) ~( _: z2 U
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? |
|