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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 C3 P. R. v6 \$ p7 d Z4 g$ xnetlogo自带的social science--traffic grid这一例子当中,
+ ^& l# J3 G/ e4 F1 E* Y+ i z# bglobals! k7 R5 `; O0 z L6 J) B
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grid-x-inc ;; the amount of patches in between two roads in the x direction
/ j$ {* j4 ]& Q. I1 X6 M0 X! d* c grid-y-inc ;; the amount of patches in between two roads in the y direction
+ t7 C( ^6 I8 Y acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 D9 P0 R# ]' P$ H" t9 `& _ ;; it is to accelerate or decelerate
, B; I: t9 e M" p' ^& N phase ;; keeps track of the phase
3 O, B. w* L, L& \( N% b- j num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
( f& l/ G! x7 p current-light ;; the currently selected light
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: h* D) z+ V, r& l/ R+ S3 a0 Y/ a ;; patch agentsets
* v! R! Q; I) [' a& T' e3 E4 q intersections ;; agentset containing the patches that are intersections Z! U/ O6 ~$ k J, L4 P: I/ T
roads ;; agentset containing the patches that are roads) U% f2 q+ Z! W/ w) {" J
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+ i& V% b2 e# f+ G4 ?) V# X; g9 Pturtles-own: f! @2 y1 U' M6 O2 \7 _+ {
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. W! u8 B$ p) o+ B/ E: b4 J% T speed ;; the speed of the turtle
E* ^- g. F3 \) |2 S. Y6 Q up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 O9 R& n7 ^2 X9 r. i/ l wait-time ;; the amount of time since the last time a turtle has moved
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0 W$ ~8 b. i( A, Z- Z( tpatches-own) {2 j- c" Z& b/ `7 @' @' I% c) e" N
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3 L j- M$ N' j% L7 l( r, t intersection? ;; true if the patch is at the intersection of two roads
* i7 J8 y0 a7 S9 W! e! V green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 B; {& G# x+ {) V8 z7 }* H2 r ;; false for a non-intersection patches.7 ` X, R0 ~3 A, o2 n
my-row ;; the row of the intersection counting from the upper left corner of the
4 _0 W0 r7 \) N7 s/ p! L4 h5 e ;; world. -1 for non-intersection patches.
2 ] \' r0 j" V9 D( Q9 C% W( L my-column ;; the column of the intersection counting from the upper left corner of the
3 i) z( u( F/ r ;; world. -1 for non-intersection patches.
) `6 }7 Q6 ]3 V1 d2 N: Y3 I my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 m! e) n7 I6 X1 e, M/ s auto? ;; whether or not this intersection will switch automatically.
1 d- {! b5 v, A" v+ R2 }& ^ ;; false for non-intersection patches.1 _! D7 ~( \& t& r9 }. ^. y _
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M ^* o4 q# Y;;;;;;;;;;;;;;;;;;;;;;/ l# _2 R% {- u8 l2 t i
;; Setup Procedures ;;
# T9 w+ b7 U6 N$ w7 Y6 M;;;;;;;;;;;;;;;;;;;;;;$ N1 |8 Y: D/ _4 k
$ }1 {& ?% _; e0 h' q0 p;; Initialize the display by giving the global and patch variables initial values.5 O. E; J- B2 J4 f. S
;; Create num-cars of turtles if there are enough road patches for one turtle to4 r1 c- Q5 H% v. {: E$ S
;; be created per road patch. Set up the plots.6 ]6 c! ^4 V, ?2 _+ |) L) c
to setup
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7 d# Z6 X+ T) c1 o$ _7 @ setup-globals
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;; First we ask the patches to draw themselves and set up a few variables% L" Z* T5 V) f* _) g$ P8 Y7 p
setup-patches
" o. Z& v+ @$ U make-current one-of intersections& K% F0 `6 e8 c* E( f. r
label-current
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; c; a4 s) n c0 _! S; y set-default-shape turtles "car"% I1 a: l2 y9 M8 r8 w
: j7 L5 t' O0 E/ |: W. r if (num-cars > count roads): f( f% _3 j4 V) ?$ Y# W% c
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user-message (word "There are too many cars for the amount of "
2 G G; ]' J! m& w( Y "road. Either increase the amount of roads "
9 Y( q1 E2 k$ \0 J "by increasing the GRID-SIZE-X or "
5 |# F1 Q5 n6 a "GRID-SIZE-Y sliders, or decrease the "
% @; Q% N9 f: _1 f "number of cars by lowering the NUMBER slider.\n"
/ Y) E4 R F( ~9 R- t9 f# ? "The setup has stopped.")* `: d9 P% l* p! b$ n) A
stop
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) | z5 ?+ e# A ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% \8 b E9 ?$ N+ _( d
crt num-cars3 B: ^9 U/ G# ]# \- Y+ h; ^
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setup-cars
2 ?) \2 `5 X n5 l5 k& t set-car-color
5 i% Y) a: ?/ h0 q record-data- C& a7 l1 R% A* |4 h6 A4 i" {5 F
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;; give the turtles an initial speed9 T U& T5 q5 m( k3 M5 u6 e2 ?7 j
ask turtles [ set-car-speed ]
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reset-ticks
5 j& G9 Z6 M2 p; yend, ?6 y5 K$ H5 F
4 C% c# ^1 ]; S1 d# M;; Initialize the global variables to appropriate values
% J/ K6 N" u1 s' }! F Z& J0 Q5 ~1 ~to setup-globals
/ T$ h& c9 V) _ set current-light nobody ;; just for now, since there are no lights yet
& p3 ~( a, O* N& Q! ?7 E2 j set phase 0
# D+ a# z* }# h/ Q } set num-cars-stopped 0
( a' v+ o' D* } set grid-x-inc world-width / grid-size-x# } w5 N( B7 I9 i
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
( P* ?. X: `/ p3 [- Q* e9 i7 Q( ]0 o set acceleration 0.099
% n( N8 ?% U4 r% c$ m# H* ]end$ w5 R6 g+ |! s, v! W( |8 K1 }1 K
}+ J" f; n6 D5 Z: U7 k& z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" |/ u- p& C9 P% F: P R) v' p;; and initialize the traffic lights to one setting* r& G( U8 ~; i: H: t
to setup-patches
& o w6 L% x+ H' Q! A, P* Z ;; initialize the patch-owned variables and color the patches to a base-color
% h: V2 S* Z' J( K( F1 ? ask patches5 {: O8 S1 q: u+ W- A
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+ V( i3 L3 B% V! V! O2 \$ V set intersection? false* w# M8 M5 A9 m, Z* C8 J+ a K
set auto? false6 D9 y7 f! v* d4 R) q
set green-light-up? true6 x. G2 g) h i4 N1 y7 e4 j
set my-row -10 C8 S$ B/ G9 H w$ x
set my-column -1
_! n1 u$ }" G set my-phase -1
/ z* |2 q' Y8 r+ \8 D# R8 i set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
! {+ r& G4 s4 C3 ?. ?9 @- j" C set roads patches with3 f7 E0 b7 q9 i# a) P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% N |) a( R; o. O, R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ h, ]/ I* [/ o: n set intersections roads with; d7 K f$ t' q& l1 f! y8 D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' d/ x- C5 @ O7 } g7 n (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( S X8 L4 ^' K) d: x4 a" _ w+ K
" x* a6 ]' A% ? ask roads [ set pcolor white ]
5 [( I+ W1 ` Q i. D9 Z setup-intersections
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# x, q( |# x* A0 y其中定义道路的句子,如下所示,是什么意思啊?3 @' a! p7 Y5 o0 ?+ U4 Q2 ?2 m
set roads patches with
! s: p$ G' b: c2 K" n& q0 n- B8 k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: C) h; d' F9 p8 F/ h7 J% v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# V( [7 l. F( J! Z9 l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? |
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