|
|
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。" D- Q! A$ o( `& ~0 b: q
netlogo自带的social science--traffic grid这一例子当中,7 h( S* Q4 o9 p( c, h0 X1 B
globals) J7 ~2 ]9 l' r; x
[) I! m$ a0 ~4 w% D2 M/ x6 U( B J
grid-x-inc ;; the amount of patches in between two roads in the x direction0 Q; }: @$ G" I( t
grid-y-inc ;; the amount of patches in between two roads in the y direction) t. W, e* Y: z- S8 F/ J
acceleration ;; the constant that controls how much a car speeds up or slows down by if
( h. }& ^; Z$ B ;; it is to accelerate or decelerate
) w6 X/ I2 {3 B/ Z phase ;; keeps track of the phase
! U# g1 s; ]/ k num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure- `! H# {) Q5 g
current-light ;; the currently selected light
! c+ j. i. @* A% ]2 b5 c& J9 P5 [+ ]
7 F' T9 I! w6 F Y ;; patch agentsets( A& ^/ A( [1 t7 T' X0 O% m( i; q9 a
intersections ;; agentset containing the patches that are intersections& V& P: X7 F3 p {# q1 K( l: x! ~
roads ;; agentset containing the patches that are roads z+ c2 x6 J+ A' o
]
8 A7 C( q+ m& {1 E6 H% Z: x! w3 O
$ l5 T6 c+ S8 ^( Q. Y1 _turtles-own
0 y4 ~5 p0 z G& s0 L, D[
" U4 p7 j: R2 ]/ s# e4 l" O# {+ I speed ;; the speed of the turtle# g$ u9 ` M3 [
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 O9 [8 N& Z$ ~, U0 o
wait-time ;; the amount of time since the last time a turtle has moved% T' t4 ` |! O* ^
]
1 ]6 ?; i8 I& Q/ J- {) f5 M' f
patches-own
* k7 ~; S. S5 y6 O) m1 { B[
: c( u+ _/ F {2 i intersection? ;; true if the patch is at the intersection of two roads
# H; @/ t! X& c! S8 ?1 ?7 } green-light-up? ;; true if the green light is above the intersection. otherwise, false., E. _. s! E5 O8 r& V% c
;; false for a non-intersection patches.4 K4 u1 q) l2 k% B7 l- Z
my-row ;; the row of the intersection counting from the upper left corner of the- B# A0 w/ O2 `5 P# Y6 K5 R
;; world. -1 for non-intersection patches.! t$ @$ v3 f! y" a9 ]2 P7 ^7 k, T
my-column ;; the column of the intersection counting from the upper left corner of the3 L& b, {; n9 S* _7 q4 l
;; world. -1 for non-intersection patches.
. x( J4 Z$ t$ P my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 g. s3 B# y/ I7 A( w1 E( m8 ]1 F auto? ;; whether or not this intersection will switch automatically.9 O; |, ~8 h6 H) }
;; false for non-intersection patches.; E4 r3 }: |- ]' m" B2 Z* T* A7 r. o
]
+ A0 i1 e2 \! _! [. z' Q) j$ O8 H. H5 B A0 r, e8 Y
( u" S" K0 d" N1 g;;;;;;;;;;;;;;;;;;;;;;
/ l! V, F* ~) W C! ^: X;; Setup Procedures ;;
8 i1 q$ k& o/ c2 d( N;;;;;;;;;;;;;;;;;;;;;;+ @) n7 C- [. W- A/ l
, x5 v' Z. F# A7 V
;; Initialize the display by giving the global and patch variables initial values.
! W) x U9 O+ u% G! [/ o9 V# D1 E g;; Create num-cars of turtles if there are enough road patches for one turtle to7 g4 |4 f- G( V. w3 H0 e
;; be created per road patch. Set up the plots.
4 R2 _$ w9 m2 D1 |, M. l3 Lto setup0 N3 i7 X$ U9 O2 e' X) `
ca; u+ i' V( `6 z/ a! p
setup-globals
' B2 C: }" e- ?( W8 d$ L2 K- ~
;; First we ask the patches to draw themselves and set up a few variables; \; a7 R3 G% `* Y
setup-patches0 ^2 k, R! G! {7 h6 i
make-current one-of intersections
% V- E# z: U4 h }% \2 V( D% H label-current/ D& S( |. o9 \& m, I& E2 d( ^
B+ g5 A3 ~. @" s set-default-shape turtles "car"" x* \0 A$ V( q& q9 _
7 U \: h8 H& `. P7 q
if (num-cars > count roads)! e& Q y2 d# q6 B, r
[5 d, X6 M- v% J$ ` u6 V3 d
user-message (word "There are too many cars for the amount of ", K+ W& e0 c3 \$ s1 Q
"road. Either increase the amount of roads "
7 X7 f' Z* S/ ]6 w) V6 @$ P4 X "by increasing the GRID-SIZE-X or "* y8 j9 S& M0 T+ K/ V# x
"GRID-SIZE-Y sliders, or decrease the "
* x% m3 `" ~4 j# g/ q5 k) T7 O "number of cars by lowering the NUMBER slider.\n"' } \: @( `; H7 Y: d5 u* g3 K8 m, f
"The setup has stopped."); I: z; ~/ G! a
stop" [- v' N0 _+ b1 l. R: }
]! `3 {5 ^# e8 t# z& A
0 }+ E5 R) H, F" x
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 L7 h9 p- i% i- W4 ^ crt num-cars. W) B) l2 z. R& G( H+ t
[
* Q: Q6 }& e7 c3 |# K2 z setup-cars
% U& N$ o' @. [ set-car-color
0 P' N7 Q0 W8 }1 s# U1 I record-data
2 P' B- M2 \0 b$ ~ ]3 e! `( F! b* B" B! i9 o+ X/ |( {
! s( R- g h! } ;; give the turtles an initial speed- u/ |! v. T8 l9 }+ _; Z
ask turtles [ set-car-speed ]6 x% x1 p0 G& S) B* ?& D# _! Y
# _9 H8 Z4 r% R; K! I. O reset-ticks
- x; d! W: B& h+ n' D* @" Wend9 e) y+ V) B) T% c6 ?
: t; G9 l. `, u;; Initialize the global variables to appropriate values
! X& {. V6 x& q x, kto setup-globals, _6 D* U0 `% b9 D1 W+ \
set current-light nobody ;; just for now, since there are no lights yet7 Y0 q7 C$ `& F
set phase 0
3 _" m" L+ v( c% U# K* P set num-cars-stopped 0
5 D" M: }, K4 e: l' T! Y set grid-x-inc world-width / grid-size-x; x8 l( J% v) X1 i3 A7 N
set grid-y-inc world-height / grid-size-y# Q; c/ m% ?* {2 B7 V6 [8 t& Q1 j
8 y! k* ]' v `0 i7 J* c
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' l) E& ?6 d, V+ O$ o1 T. _ set acceleration 0.099& u( ]* i0 R5 |6 S) w$ T9 z
end" i- p& l1 w5 i7 b% j! } o
. I7 j# j* f& o6 J/ p9 S# j;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 c" p# ~7 Q9 r& \
;; and initialize the traffic lights to one setting6 }9 Y5 z. t3 Z- h% y: f3 S4 f) Q
to setup-patches! _ ?0 Z$ e) o4 ]0 ?$ ~6 S
;; initialize the patch-owned variables and color the patches to a base-color
) U, O# `( s+ B$ d0 V8 g ask patches
' _* S+ F: p4 F" t( W4 W1 C3 ~ [) @8 h R4 V$ V. V
set intersection? false: D' l* C% U9 P) G) F
set auto? false
4 o6 @* i1 a4 _ W2 z set green-light-up? true A; y6 r0 {' a1 M9 P
set my-row -1
: k# I: }5 N9 o4 k set my-column -1
0 L1 d) Y/ D/ I+ T set my-phase -1. J. J3 N N* z5 k$ q* A" v- L5 z
set pcolor brown + 3" I; J6 |& S$ _- x" D$ t5 D
]
. ^) u1 x7 F$ G8 C p4 w: z. c& z! _! y+ @4 `2 {8 n6 D
;; initialize the global variables that hold patch agentsets
$ e1 c6 a6 j9 ^* X( m- a F set roads patches with
' `' ^8 v. P! ^8 m) i- } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 {& W1 v4 ~2 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 ], k; w+ O L5 H5 n- e set intersections roads with$ ~( O c r9 d! q1 p7 b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 t1 V8 L' ~: ]( X; ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) g7 {# _0 N( k; `" t9 l
$ J) K& J, H/ Q' |6 `/ j
ask roads [ set pcolor white ]
. n2 I0 Y7 N) N: Q7 c3 N setup-intersections! Z0 \' e2 k! l8 q5 |7 x
end( n% @3 Q1 r( s# z Y U9 f' D! D! b
其中定义道路的句子,如下所示,是什么意思啊?
) Y- ?5 E+ m$ } set roads patches with
( E8 |, ^7 _) \2 p9 i) E- b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 O/ M" K. l$ }/ o0 I8 ^6 o: x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* p( Q* r9 ]# X; g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? |
|