|
|
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。8 F) ]5 m' _ O8 ?
netlogo自带的social science--traffic grid这一例子当中,
! v5 u" \# E2 Bglobals: D5 `. _4 Z6 e. |* w
[
$ J1 o& j9 q: {8 I) ? grid-x-inc ;; the amount of patches in between two roads in the x direction
- U: A$ ?9 ? P9 M# ^8 i8 B1 J grid-y-inc ;; the amount of patches in between two roads in the y direction& R7 J1 d5 Z6 w! b- _
acceleration ;; the constant that controls how much a car speeds up or slows down by if d7 u9 D5 A3 F% n3 }9 f* r+ b; ?
;; it is to accelerate or decelerate
: `. j. C7 L) H9 f" C phase ;; keeps track of the phase! J" v4 N! T! _ `0 m
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 B' V( G7 U& X) P: E
current-light ;; the currently selected light+ _" N4 P$ O }+ C+ K0 r: q1 Z6 g
% a2 b% d# `7 C' l# N: r. I) a8 ?
;; patch agentsets
! L5 d1 }5 B7 u5 `4 g intersections ;; agentset containing the patches that are intersections! b7 A! x+ M3 Y9 b: Q1 s }7 ~% \4 d
roads ;; agentset containing the patches that are roads. T& v- w) |1 v3 X6 ]
]' s: |- l( r+ G' u1 e. B% ?% E1 f
9 t% {" l" r8 U9 e9 t, \' Hturtles-own
5 |3 e/ r5 |5 \' E. D[- r# o& ?$ ^! I4 ?
speed ;; the speed of the turtle
% v: [/ d/ g8 x/ z$ s) g$ L up-car? ;; true if the turtle moves downwards and false if it moves to the right2 S$ Z! I$ q1 |4 P
wait-time ;; the amount of time since the last time a turtle has moved- [5 D' y! L- [6 u# `; w& W
]& b% q: @4 J/ k6 y1 O+ ?
6 w0 M7 v3 ]. v+ [
patches-own" p4 r. k ~8 R: j w: O# u
[" c; r# f1 A8 w; G+ |9 I
intersection? ;; true if the patch is at the intersection of two roads
" V% w4 S# u; K3 z green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ }) U9 ] ?* ~- U7 f; P) B$ Y! F* H ;; false for a non-intersection patches.% n/ V1 i [ h9 |( [/ N- G
my-row ;; the row of the intersection counting from the upper left corner of the: Z6 s8 [+ L. ?! V' b
;; world. -1 for non-intersection patches.
7 p$ s( d) q6 d d. ? my-column ;; the column of the intersection counting from the upper left corner of the
( c. }. p" y- \1 v ;; world. -1 for non-intersection patches.
g) v7 y6 m' r4 K my-phase ;; the phase for the intersection. -1 for non-intersection patches.. c) L4 _! q, J( [ q
auto? ;; whether or not this intersection will switch automatically.: R/ Z+ i0 h0 A8 r* Y
;; false for non-intersection patches.) U/ ^/ \7 @5 ]9 p# V' D4 N
]
+ R% q$ i! o/ J; z. ^5 D! P
4 t2 m& a; d! a& c v+ O/ w# f* ]# k b. B
;;;;;;;;;;;;;;;;;;;;;;
$ j6 C) c$ N; i" O+ a& c% U;; Setup Procedures ;;
6 p. u- z# w- k7 x/ i& |;;;;;;;;;;;;;;;;;;;;;;5 ?6 @$ z& R" j
/ R/ `: E0 _+ O& x+ p& n;; Initialize the display by giving the global and patch variables initial values.. g1 L0 Q! X/ x7 ]% [& E9 a
;; Create num-cars of turtles if there are enough road patches for one turtle to5 V m, \/ p4 I- F$ n6 n& o4 O) m
;; be created per road patch. Set up the plots.& L8 C4 Y9 K0 d7 M4 m
to setup6 P7 a; z) h& E# T4 V+ L
ca
$ }3 s" o) \7 |4 Y1 i& U" K1 y setup-globals
1 l" b- a Y8 }9 [! a3 }
& W7 g# a5 t/ X; b5 } ;; First we ask the patches to draw themselves and set up a few variables
& H* E. X1 C' t5 w setup-patches
# | J% P# X) G: F2 { make-current one-of intersections
- w3 I y; ^ Z6 |$ E label-current
0 r* `; ^0 C, p: [5 D' E' i
/ n8 w% N/ n) F* q1 B0 } set-default-shape turtles "car"! o& N" f* O9 I9 n, @! @9 S
5 S( ]6 X% k& X! \2 V. R2 r
if (num-cars > count roads)1 ]: o% ?/ [# U& q/ d) w
[
) r4 i: G2 }: _9 e1 m user-message (word "There are too many cars for the amount of "
" S4 Z" r$ Y! A. A "road. Either increase the amount of roads ", D* h. t; B2 m9 f
"by increasing the GRID-SIZE-X or "' o9 Y1 F4 p3 E8 _4 N5 Y- o' I4 ?
"GRID-SIZE-Y sliders, or decrease the "+ i/ b1 f1 U7 u" |4 V
"number of cars by lowering the NUMBER slider.\n"& N- N) n9 Z$ x% ?2 r8 T
"The setup has stopped.") T- H. u- N3 Z1 v* ?
stop7 N, I1 q9 A+ R. h+ F
]
9 J6 i. A# G, \: U! h" y
, V# I$ `+ e0 r ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ T; Y+ E- n5 t2 V U1 e) W crt num-cars' P6 w8 L& g! Q$ u/ N
[9 n" K; u; r: o! j5 y. X) H7 q2 D) l
setup-cars
- C j6 C" \6 H* J7 W set-car-color
0 ^- V% K0 ]( R, L record-data
1 F& j$ p9 i# j6 q ]
) v1 U+ S: V6 F p& @1 H1 Z: Q8 o+ w
;; give the turtles an initial speed6 }% k1 ^9 e8 F( ]) s1 u9 E" S
ask turtles [ set-car-speed ]/ y! p1 Y! ?5 @2 R* `( @
, t- |: q$ u: f, }& G9 ^% u
reset-ticks
- r# r- a9 V4 ^2 Send. r# v5 S9 ]8 h* e. P; s
+ A" N4 w; T$ n6 F* q0 M* S2 Q;; Initialize the global variables to appropriate values
: }4 {( v, b$ D2 Pto setup-globals. n/ ]! e; \' T1 r7 _
set current-light nobody ;; just for now, since there are no lights yet
! z' q9 D" I- i set phase 0
: \. E- i6 ^7 k! l, i set num-cars-stopped 0& p/ t% f" q+ i8 i2 c: Z4 A
set grid-x-inc world-width / grid-size-x
7 I }( D( T; H2 ^ set grid-y-inc world-height / grid-size-y( X& M) L3 R7 r; b7 [% L
4 R5 ^$ |+ m" G# f
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 q6 y; N8 }7 O* h+ c. p
set acceleration 0.0997 n! a! T: k5 X3 q1 K
end
# V( |2 V, c4 R# }: H# t
! j+ C. j8 u* B" m/ Y& z' p9 _;; Make the patches have appropriate colors, set up the roads and intersections agentsets," p" k/ J. _: Y0 \% v
;; and initialize the traffic lights to one setting
& I! Q( f; T0 g$ P& Q9 K4 I ato setup-patches, ?; A" M( I3 U3 q
;; initialize the patch-owned variables and color the patches to a base-color
3 T" H; S1 p% }+ s ask patches
4 x3 M, |, C' W" ]8 k [
5 r k8 F3 r3 H% q8 E4 W set intersection? false/ S% m. E( A- E& G7 c6 G1 Q
set auto? false3 F5 @% M; f1 S
set green-light-up? true; ?% k v* Q+ ~! L
set my-row -1
) d: E2 r" M3 y; r- Z2 e set my-column -1+ } ?. x" o- D0 Y9 l
set my-phase -1
, g3 v$ w" F6 p set pcolor brown + 3
# M- q, [! j$ [) I7 d ]
- s7 S5 Z% N& M, X+ a! g5 J
) n7 F# T: l# i ;; initialize the global variables that hold patch agentsets
- U; t4 ]. u2 E set roads patches with8 e& e% g1 n+ X. U3 B6 V! ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# D6 g. e& D4 a+ [* Q$ ~9 ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 W$ o p' W7 B( m# P8 f- ?! R; ? set intersections roads with! j* }) S9 [1 ^! t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ ~. @$ A7 G9 x- N' W6 u3 ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( D3 w3 {- t- H) Q; f( K" s( G" N. J) W, }1 r
ask roads [ set pcolor white ]
8 V( W9 [1 o* I q setup-intersections
$ h! D# U/ ~- @- k! E0 rend \0 }/ i( e% u
其中定义道路的句子,如下所示,是什么意思啊?9 z2 `/ G6 K. R% U& w6 m) E; z
set roads patches with
4 `+ D' L8 B; P. r. ^ l) ? O) m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 ]0 l( J7 T o" A6 M; y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 s# t" Y3 E- V/ m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? |
|