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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。2 K" F6 W& p+ B( K
netlogo自带的social science--traffic grid这一例子当中,: }. H/ F- G$ P; d
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
9 Q7 W H4 X/ l1 c' I2 P, W( [ grid-y-inc ;; the amount of patches in between two roads in the y direction
* E% G# l- E3 E acceleration ;; the constant that controls how much a car speeds up or slows down by if
a; `- T# ~0 |" Q8 J L: \! K ;; it is to accelerate or decelerate9 Q' h! X' M1 g( c
phase ;; keeps track of the phase5 G1 R: z) ]7 I* c
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
2 \% f4 ^6 N1 ^$ ~, h current-light ;; the currently selected light
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;; patch agentsets
) |+ W/ f, ]: G* f( K intersections ;; agentset containing the patches that are intersections
/ f# y) |0 f" S roads ;; agentset containing the patches that are roads: ]" {( \6 L0 p/ \0 D# h1 V
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turtles-own
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speed ;; the speed of the turtle: M; O1 {. A }0 h# w! x
up-car? ;; true if the turtle moves downwards and false if it moves to the right, N3 g- k5 {' G- a9 i) f2 x
wait-time ;; the amount of time since the last time a turtle has moved- p ], H! U3 ~: [' ^* g2 [
]
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads: V' r, s# l8 {/ [8 V, v: C8 _ h
green-light-up? ;; true if the green light is above the intersection. otherwise, false., s* @( P, S5 l( ~ B' M" `" P
;; false for a non-intersection patches.; A& d: d# M4 A/ @6 I
my-row ;; the row of the intersection counting from the upper left corner of the0 m4 O) v% a" W
;; world. -1 for non-intersection patches.+ m1 t- p" T5 g( @2 X* }3 u1 ?
my-column ;; the column of the intersection counting from the upper left corner of the, p p* K! M) ~) A, {
;; world. -1 for non-intersection patches.1 Q$ ^* Z9 l" X4 K
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ a& E6 E. L+ | v% C8 l* f4 O. Z5 \ auto? ;; whether or not this intersection will switch automatically.& a8 z) i1 Y" U% r
;; false for non-intersection patches.
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" V8 W- f& n. U- o8 [;;;;;;;;;;;;;;;;;;;;;;& Q% ^% b$ Q/ @- w0 Q9 u7 I
;; Setup Procedures ;;
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# C; C1 _- j. _2 I9 l' };; Initialize the display by giving the global and patch variables initial values.) F6 X7 M8 J0 b0 d& E9 o0 q1 h
;; Create num-cars of turtles if there are enough road patches for one turtle to1 P) F: y% w9 ~. n
;; be created per road patch. Set up the plots.! R* n* n! t2 K
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
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8 N& D: V) ^. h( |/ A& [ set-default-shape turtles "car"
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4 W$ S: \, I/ X; R. D" A8 O if (num-cars > count roads)6 ^( P, m% V$ l
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user-message (word "There are too many cars for the amount of "; @* c0 O5 C. q0 @& ^( }' J v% L' Q
"road. Either increase the amount of roads "
0 I/ j7 R' y7 D' t "by increasing the GRID-SIZE-X or "# ?3 q7 k( ?$ |, w1 f8 r
"GRID-SIZE-Y sliders, or decrease the "
; b& u! P. D) Z8 p% c "number of cars by lowering the NUMBER slider.\n"
, O6 ^2 B, q% @5 Q4 |4 V% ] "The setup has stopped."); w# q: ]" b+ z$ ^8 Q3 n, {& ~
stop8 ~; [: ~7 N5 ^8 f( Q
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ n, h% C8 K7 n6 }3 Q( ? crt num-cars! B v; f& D" R8 l" ]8 l
[
/ u$ J) E: r2 }5 M) f setup-cars
1 ?1 i7 u8 x) a. B9 j5 L set-car-color5 J4 |* b9 A0 O% N4 _$ U* A" B8 l
record-data1 w% t8 z5 `" X' @# f
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6 [/ x" {, U* J& }) U( O ;; give the turtles an initial speed
! T6 {7 E7 Y% m! ` j% Y1 t ask turtles [ set-car-speed ]. {1 f/ \9 |+ S L; }4 U- W) P' S
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reset-ticks
$ ] w- O* o# \5 cend
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;; Initialize the global variables to appropriate values
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0 a; Z, ]$ c0 F: P, c, \' R set current-light nobody ;; just for now, since there are no lights yet
! F$ l }) }3 ^' H7 |# M7 | set phase 0
+ Z# e/ ^0 e! `- r. B) F: C0 n set num-cars-stopped 0
) E# `" J+ x* v5 [. f set grid-x-inc world-width / grid-size-x g1 R7 u& c5 |" _+ Z
set grid-y-inc world-height / grid-size-y
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. F1 n1 Y0 w( n; U. \) V, [: c/ | ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ h6 K; T; c$ B set acceleration 0.099
J- @6 c j8 ?+ P% [/ ^% lend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, U7 S' n- K+ Q% s
;; and initialize the traffic lights to one setting
9 T! r% g7 m8 Nto setup-patches
2 _" s& h: s: i* w+ J& Q ;; initialize the patch-owned variables and color the patches to a base-color1 y+ G! `% m. G% J% p9 \4 ^- k+ a
ask patches9 j/ S* I c0 @% D2 X0 R
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( v w' P* l& g" t4 R! b set intersection? false
2 M3 T" u) q9 `8 K) X% o+ |1 h0 a set auto? false: {' j6 V6 |6 V$ t
set green-light-up? true/ n/ m! z& u' D7 I
set my-row -1
5 E+ p& x! M* V; v set my-column -1% J0 y0 j$ | w4 P4 E
set my-phase -1" k0 X1 N0 |' x1 z% o
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets0 Y) E; t; O+ T4 P9 r6 S' @) A
set roads patches with( ]- v: w8 l+ l& F
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' p. o/ E, {4 Z2 Z6 C- W2 Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 W* l: T' A6 h$ W& d$ r5 G8 c
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end
' I% J5 M( \! K. c其中定义道路的句子,如下所示,是什么意思啊?
6 S: \9 n* ^3 g9 T" m4 a set roads patches with
# j, Y. `5 r7 K% ?* \& X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
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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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